Dissertations / Theses on the topic 'MBBR'

Mestrado em Gestão Ambiental, Materiais e Valorização de Resíduos
O presente trabalho pretendeu analisar a aplicabilidade do reactor do tipo Moving Bed Biofilm Reactor (MBBR) no tratamento de efluentes vínicos. A natureza dos efluentes provenientes das adegas depende da região e do tipo de vinho processado e, para além disso, a sua quantidade e a qualidade variam significativamente ao longo do ano. Os principais objectivos deste trabalho foram analisar a aplicabilidade do reactor MBBR no tratamento de efluentes vínicos a operar com um tempo de retenção hidráulico de 24 horas, comparar o desempenho de reactores quando são utilizados meios de enchimento com características diferentes, comparar o desempenho de reactores com e sem recirculação de lamas e analisar o comportamento hidráulico deste tipo de reactores com e sem a presença de biomassa. Foram realizados ensaios em cinco reactores à escala laboratorial, em que quatro deles tinham enchimento, dos quais dois operaram com recirculação de lamas e os outros dois sem recirculação. O quinto reactor simulou um reactor de lamas activadas convencional com recirculação de lamas. Utilizaram-se dois tipos de enchimento, o Bioflow 9 e o Bioflow 40. Os modelos de escoamento hidráulico dos diferentes reactores foram determinados recorrendo a ensaios de tracer com e sem a presença de biomassa. Os ensaios efectuados demonstraram que os reactores que possuem enchimento têm comportamentos hidráulicos idênticos, sendo ambos caracterizados por modelos de mistura perfeita com zonas mortas e a percentagem de zonas mortas diminui nos ensaios realizados com biomassa (35-36% de zonas mortas para 10-12% de zonas mortas), concluindo-se que o grau de mistura melhora com a existência de biomassa. O reactor de lamas activadas foi caracterizado, em ambos os ensaios, pelo modelo de mistura perfeita com zonas mortas e curto-circuito, havendo uma ligeira alteração dos parâmetros quando o reactor opera com biomassa (28% de zonas mortas, 9% de curto-circuito para 26% de zonas mortas e 10% de curto-circuito). No presente estudo verificou-se que as condições limite de operação dos reactores foram alcançadas para um TRH de 24 h, 50% da altura do reactor com enchimento Bioflow 9 e o CQOalimentação = 8000 mg.L-1 (8,0. kgCQO.m-3.d- 1). Nestas condições o efluente tratado apresentou um CQOsolúvel = 1500 mg.L-1 correspondente a uma percentagem de remoção de CQO de 81%. Verificou-se também que para todos os reactores e em todas as condições operatórias testadas até à carga orgânica 6,5 kgCQO.m-3.d-1, a percentagem de remoção de CQO foi superior a 90%. Os resultados mais elevados registaram-se na carga 6,0 kgCQO.m-3.d-1, com valores próximos de 98%. Os valores de CQOsolúvel do efluente tratado nos diferentes reactores não ultrapassaram os 150 mg.L-1 até à carga 6,0 kgCQO.m-3.d-1, verificando-se um aumento significativo em cargas superiores. Concluiu-se que a recirculação de biomassa suspensa não exerce efeitos positivos na eficiência dos reactores, no entanto durante o período de arranque diminui significativamente o tempo de estabilização dos mesmos. ABSTRACT: The present study intended to evaluate the applicability of a MBBR reactor for the treatment of winery wastewaters. The wastewater originated in wine cellars strongly depends on the region and the type of wine processed and also its quantity and quality changes substantially during the year. The aims of this experimental study were to analyse the applicability of a MBBR reactor for the winery wastewater treatment operating with a hydraulic retention time of 24 hours, to compare the performance of reactors when different packing bed materials were used, to compare the performance of reactors with and without sludge recycling, and finally to examine the hydraulic behaviour of each reactor with and without biomass. Experiments were conducted with five lab-scale reactors where four had packing material, two operating with sludge recycling, two without it and a fifth reactor simulated a conventional activated sludge system. Two types of carrier elements were used, the Bioflow 9 and the Bioflow 40. The hydraulic flow models for the five reactors were determined recoursing to experimental studies with tracer elements in the presence and in the absence of biomass. Tracer studies demonstrated that the reactors filled with carrier elements had identical flow models and behaved as complete mixing reactors with dead spaces. The fraction of dead spaces decreases in experiments with biomass (35-36% of dead spaces to 10-12% of dead spaces), concluding that the degree of mixture improves in the presence of biomass. The activated sludge flow model was characterized, in both cases, as complete mixing reactor with dead spaces and short-circuiting with a slightly difference on the parameters in the presence of biomass (28% of dead spaces, 9% of short-circuiting to 26% of dead spaces and 10% of short-circuiting). In the present study it was verified that the limit operation conditions of the reactors were reached for a HRT of 24 h, 50% of the reactor volume packed with Bioflow 9 and a CODfeed= 8000 mg.L-1 (8,0 kgCOD.m-3.d-1). At this operational conditions the treated wastewater had a CODsoluble = 1500 mg.L-1 corresponding to a COD removal rate of 81%. It was also verified that for all the reactors and in all the operation conditions up to the organic load applied of 6,5 kgCOD.m-3.d-1, the COD removal rate was higher than 90%. The highest results were obtained at an organic load of 6,0 kgCOD.m-3.d-1 with values near 98%. The COD soluble values of the treated winery wastewater in the different reactors didn’t exceed 150 mg.L-1 up to an organic load of 6,0 kgCOD.m-3.d-1, and for higher loads a significant increase was verified. The sludge recycling doesn’t affect in a positive way the efficiency of the reactors, although during the start-up phase the reduction of the stabilization time was significant.

Mestrado em Estudos Ambientais
In this study cheese-whey conversion into VFAs as a source for biopolymers production was investigated. Cheese-whey was chosen due to its high organic content being a by-product from the cheese production factory, as a part of valorisation methodology for industrial waste streams. Cheese-whey acidification process was used as an alternative to the waste treatment technologies. To study the acidification of cheese-whey, a set of experiments was carried out to produce short-chain volatile fatty acids (VFAs), in order to find out its ratio to the total chemical oxygen demand (tCOD) of feed present in the reactor. The proportional amounts of Acetic, Propionic and i-Butyric acids towards the rest of the VFAs were also important in order to evaluate the MBBR efficiency for different operational parameters such as hydraulic retention time (HRT), alkalinity and organic load rate applied (OLR). To fulfil these goals the mass balances of the system were performed. The maximum production rates of Acetic, Propionic and i-Butyric acids associated with simultaneous changes in OLR and alkalinity at a constant HRT of 12 h, were investigated (70% and 65% of total VFAs produced – at Phases 0 and 4, respectively). The degree of acidification of cheese-whey to the short-chain VFAs was about 33% and 27% of the influent COD concentration, at Phases 0 and 4, respectively. The optimum operational conditions under study where the maximum production rates of Acetic, Propionic and i-Butyric acids occurred were at an alkalinity of 3.6 gCaCO3/L and an OLR = 35 gCOD/L*d (Phase 4). At this optimum conditions for acids production, the average rate of COD removal was equal to 20% and the rate of methane production was equal to zero.

The significant rise in the number of micro-breweries in North America has increased the need for efficient on-site industrial wastewater facilities. Brewery wastewater is considered to be a high strength food industry wastewater with high variability in terms of both organic and hydraulic loading. Small breweries require cost-effective, reliable, and simple to operate treatment technologies to properly manage their brewery wastewaters. Moving bed biofilm reactor (MBBR) technology has shown promise at the lab-scale and full-scale with respect to brewery effluent treatment. MBBR systems have the capability for short hydraulic retention times (HRT), high organic loading rates, as well as increased treatment capacity and stability due to biofilm retention, all within a compact reactor size when compared to other aerobic and attached growth treatment options. Two MBBR systems utilizing two different carrier types (Kaldnes K5 and Kontakt), and a suspended growth (SG) control reactor, were used in this study to investigate the impacts of surface area loading rate (SALR) and HRT on attached growth (AG) and SG kinetics and carrier type for brewery wastewater at 2000 mg-sCOD/L. An increase in SALR from 10-55 g-sCOD/m2/d while at an HRT of 12 hr resulted in no significant impact in total volumetric removal rates between the MBBR systems and the SG control reactor; however, MLSS concentrations were lower for the MBBR systems at SALRs below 55 g-sCOD/m2/d, which indicated AG contribution. Over 92% soluble chemical oxygen demand (sCOD) removal was achieved at each SALR in each of the three reactors. These results indicated that the reactors were substrate limited and SG controlled. Due to the SG dependency, the difference between the two types of carriers was indeterminate. A decrease in HRT from 12-3 hr while maintaining an SALR of 40 g-sCOD/m2/d resulted in a shift from SG to AG dependency in the MBBR systems. The total volumetric removal rates for the MBBR systems were significantly higher at HRTs of 3 and 4 hr as compared to the SG control reactor. The AG volumetric removal rates from both MBBR systems were highest at an HRT of 3 and 4 hr. At an HRT of 12 hr all three reactors maintained over 92% sCOD removal; however, at an HRT of 4 hr the SG control reactor dropped to 88% and at 3 hr to 61%, whereas the MBBR systems maintained 95% removal at an HRT of 4 hr and only decreased to 73% at 3 hr. These results indicated that the MBBR systems were more effective at lower HRT than the SG control reactor, with no significant difference observed between the two carrier types tested. Biofilm morphology and viability from each of the two carriers utilized in the study of moving bed biofilm reactor (MBBR) treatment of brewery wastewater were investigated using stereoscopy and confocal laser scanning microscopy (CLSM) in combination with live/dead cell staining. Both carriers demonstrated thicker and more viable biofilms at high SALR and denser and less viable biofilms at low SALR. At lower HRT, the carriers reacted differently resulting in thicker, but less dense biofilms on the Kontakt carriers and thinner, but more dense biofilms on the K5 carriers. However, no trend in cell viability was observed with change in HRT. Although the systems were suspended growth (SG) dominated, based on the MBBR kinetics and carrier biofilm morphology and cell viability, either carrier would be a viable choice for an MBBR treating brewery wastewater at HRTs between 4 to 12 hr and SALRs between 10-55 g-sCOD/m2/d.

Skogsindustriellt avloppsvatten behöver genomgå flertalet reningsprocesser innan det kan återföras till recipient. Vid Stora Ensos bruk i Skoghall används en luftad damm med slamåterföring som biologisk rening. Extraktivämnen i avloppsvatten försvårar luftning i dammen och problem med reningen kan uppstå då kommande skärpta utsläppskrav ska efterföljas från och med 2018. För att möjliggöra en kommande produktionsökning samtidigt som skärpta utsläppskrav följs driver nu Stora Enso ett investeringsprojekt för att effektivisera avloppsvattenreningen. En utredning ska genomföras med syfte att redovisa om ett försteg till den luftade dammen i form av en MBBR (Moving Bed Biofilm Reactor) skulle kunna underlätta rening i den luftade dammen. Om så är fallet kan en ökad produktion vara möjlig utan att ändra på dagens luftade damm samtidigt som utsläppsvillkor uppfylls. Detta är en fortsatt utredning av Karin Arvsells arbete som undersökte MBBR och luftad damm i labbskala. Stora skillnader mellan dessa arbeten är att vatten direkt från produktionen kontinuerligt går till försteget och att temperaturen i reaktorn inte regleras utan beror av vilka vattenflöden som skickas till luftad damm. En pilotanläggning byggdes upp på Stora Enso Skoghalls bruk där en Cipax-tank användes som reaktor och en bottenluftare byggdes på plats av en membranslang från luftad damm. Ett delflöde av det totala avloppsflödet till luftad damm leddes till reaktorn. Slang för inflöde gick in i botten av tanken för att bidra till omblandningen, resterande omblandning stod luftarsystemet för. Tanken var fylld med 800 liter vatten som reagerade med mikroorganismer växande som en biofilm på bärare. Uppehållstiden varierades med hjälp av en manuell ventil. För att utreda hur robust försteget är i förhållande till produktionsvariationer har TOC- och kloratreduktion analyserats samtidigt som tester har genomförts på ytaktiva ämnen, närsalter, SÄ, temperatur, VFA, SVI, EDTA, HRT och syrehalt. Luftningsförsök för att utreda hur effektiviteten på syresättningen påverkas av ett försteg samt kartläggning av mikroorganismer genomfördes. Pilotförsöken delades upp i tre olika försöksperioder. Under de 19 första dagarna genomfördes testperiod 1 där vattnet luftades i reaktorn utan bärare. Försöksperiod 2 var 45 dagar lång där avloppsvattnet reagerade med mikroorganismer växande som en biofilm på bärare. Försöksperiod 3 som var 16 dagar lång inleddes med att reaktorn isolerades. Utformningen av försöksperiod 3 är ett resultat av provsvar från försöksperiod 2 där det framkom att temperaturen sjönk nämnvärt under de timmar vattnet befann sig i reaktorn. Testperiod 2 visade reduktion av samtliga parametrar med en medelreduktion av TOC på 40 % och 86 % reduktion av klorat. Vid ytspänningsanalys visades en högre ytspänning på utgående vatten vilket tyder på att ytaktiva ämnen brutits ner. Detta underlättar luftningen vilket sågs tydligare efter luftningsförsök på ingående och utgående vatten där hastigheten för syretransporten dubblerades. Både frisimmande organismer och protozoer i form av klockdjur och toffeldjur hittades i vattnet. I samband med uppstart av testperiod 3 var CTMP-produktion och blekeri stoppat vilket ledde till att kvarvarande avloppsflöde hade en ingående temperatur på 51°C. Den höga temperaturen och det förändrade innehållet i avloppet samtidigt som reaktorn isolerades bidrog till att mikroorganismerna slogs ut. Klorat reducerades med 93 % och TOC reducerades med 19 %. Reduktionsgrader av övriga parametrar var lägre än tidigare och vid luftningsförsök visades ingen förbättring av syretransporten. Reduktionsgrader har varierat från dag till dag men då rimliga orsaker är kända kan resultaten anses trovärdiga, vilket innebär att ett biologiskt försteg i form av en MBBR som hanterar inkommande avloppsvatten med dess varierande temperatur kan underlätta rening för luftad damm. Ytaktiva ämnen bryts ner under den korta reaktionstiden i försteget och syretransporten dubbleras. Vid produktionsstörningar kan termofila förhållanden råda istället för mesofila som är fallet vid normalproduktion. Detta kan slå ut mikroorganismerna vilket påverkar avloppsvattenreningen negativt. För att lösa problemet kan eventuellt varma flöden ledas direkt till luftad damm eller att genom kylning hålla ingående temperatur under 45°C.
Paper mill wastewater passes through several different purification steps before being reintroduced to the recipient. Stora Enso paper mill in Skoghall uses an aerated lagoon with sludge recirculation as biological treatment. Extractives in wastewater aggravates the aeration in the pond and problems with the purification can occur when stricter emission requirements needs to be followed from 2018. Stora Enso is now running an investment project to improve the efficiency of the wastewater treatment to enable future production growth while stricter emission standards are followed. A pre-treatment step before the aerated lagoon designed as a MBBR (Moving Bed Biofilm Reactor) will be analyzed to present whether it can ease the wastewater treatment in the aerated lagoon or not. If so, production growth could be possible without change the present aerated lagoon while emissions conditions are met. This is a further investigation from Karin Arvsells work that studied a MBBR and aerated lagoon in lab scale. Large differences between these studies are that the wastewater goes to the pre-treatment continuously and the temperature is not regulated. A pilot plant was built at Stora Enso Skoghall mill where a Cipax-tank was used as a reactor and an aerator was built with membrane from the aerated lagoon. A partial flow of the total wastewater flow to the aerated lagoon was passed to the reactor at the bottom of the tank. The incoming wastewater and the aerator mixed 800 liters of water with the microorganisms growing as a biofilm on the carriers. The hydraulic retention time was controlled with a manual valve. TOC- and chlorate reduction, extractives, nitrogen, phosphorus, suspended solids, temperature, VFA, SVI, EDTA, HRT and oxygen content are analyzed to find out how robust the pre-treatment is. Tests were made to analyze how effective the oxygen dissolves after a pre-treatment and to identify the microorganisms in the wastewater. The experiments were divided into three different periods. Under the first 19 days was trial 1 performed where the water reacted in the MBBR without carriers. Trial 2 was 45 days long and the wastewater was pre-treated with microorganisms growing on carriers. Trial 3 lasted for 16 days and then the wastewater was treated in an isolated tank with carriers. The design of trial 3 was a result of the test results from trial 2 where the temperature dropped significantly during the hours the wastewater was treated in the reactor. Trial 2 showed reduction of all parameters with an average reduction of 40 % of TOC and 86 % reduction of chlorate. Surface tension analysis demonstrated a higher surface tension after the pre-treatment step which indicates that extractives were decomposed. The higher surface tension will ease the aeration in the aerated lagoon which was shown in the aeration tests were the rate of oxygen transport was doubled. Both free-swimming organisms and protozoa were found in the water. At the start of trial 3 the production of CTMP and the bleaching process were stopped. As a result, the remaining wastewater had a temperature of 51°C. The high temperature and the changed content of the wastewater at the same time as the reactor was isolated resulted in an elimination of the microorganisms. Chlorate was reduced by 93 % and TOC by 19 %. The reductions of the other parameters were lower than before and the aeration trials showed no improvement in oxygen transport. The reduction varied from day to day but since reasonable causes are known, the results are considered reliable. This means that a biological pre-treatment step in form of a MBBR can ease the purification in the aerated lagoon. Extractives are decomposed during the short reaction time and the oxygen transport is duplicated. If the production is disrupted, thermophilic conditions may occur instead of mesophilic conditions which are the normal setting. This may eliminate the microorganisms which affect the wastewater treatment negatively. To solve the problem, the hot water could be led directly to the aerated lagoon or by cooling the water keep the incoming temperature under 45°C.

O processo de tratamento de esgoto por lodo ativado pode ser adaptado para o recebimento de maior carga orgânica ou para a remoção de nitrogênio por meio da introdução de suportes plásticos móveis, em um processo conhecido por IFAS Integrated Fixed-Film Activated Sludge. O objetivo do projeto é avaliar comparativamente os desempenhos dos sistemas de lodo ativado e IFAS na remoção de matéria orgânica e nitrogênio de esgoto doméstico, associados à variação da idade do lodo com referência na biomassa suspensa. O efeito da adição de suportes plásticos móveis em sistemas existentes de lodo ativado é avaliado como forma de subsidiar análises de viabilidade de emprego dessa solução para a ampliação e adaptação de estações de tratamento de esgotos domésticos. A pesquisa foi desenvolvida em escala piloto, mantendo dois sistemas em funcionamento em paralelo, um representando um sistema de lodo ativado com remoção de nitrogênio e outro idêntico, exceto para a introdução dos suportes plásticos móveis. Desta forma, foi possível atribuir a diferença nos resultados à presença de biomassa aderida. Foram utilizados elementos suporte com área superficial específica de 300 m²/m³ e fração de enchimento de 50%. Ambos os sistemas foram mantidos em operação estável e eficiente, considerando a remoção de matéria orgânica. No entanto, o sistema IFAS teve melhor desempenho na remoção de nitrogênio em todas as fases experimentais, confirmando as vantagens antecipadas. Os resultados foram verificados em termos de taxas de aplicação previstas para cada porção de biomassa, de acordo com as idades do lodo estudadas.
The activated sludge wastewater treatment process can be retrofitted to either receive larger organic loads or for nitrogen removal by introducing plastic media carriers, in a process known as IFAS Integrated Fixed-Film Activated Sludge. The project aims to comparatively assess the performances of activated sludge and IFAS systems in removing organic matter and nitrogen from domestic sewage, associated to the variation of the sludge age with reference to the suspended biomass. The effect of adding plastic media carriers on existing activated sludge systems is evaluated as a subsidy for prefeasibility analysis of using this solution for the upgrading and retrofitting of municipal wastewater treatment plants. The study was developed on a pilot scale, operating two systems in parallel, representing an activated sludge system with nitrogen removal and another identical system except for the introduction of plastic media carriers. Thus, it was possible to assign the difference in results to the presence of attached biomass. Carriers were used with 300 m²/m³ specific surface area and 50% filling fraction. Both systems were kept under stable and efficient operation considering the removal of organic matter. However, the IFAS system had better performance at removing nitrogen in all experimental phases, confirming the anticipated advantages. The results were verified in terms of application rates expected for each portion of biomass in accordance with the sludge ages studied.

This master thesis is about mathematical modelling of the anammox process with a moving bed biofilm reactor (MBBR) for a reject water application. Specifically, the aim of my research was to find out whether the model proposed by Erik Lindblom in (Lindblom et al. 2016) is a good model for this purpose and worth continuous research and optimization. The code for the model, implemented in Matlab/Simulink, was given; although not initially functioning in the given condition. Some modifications needed to be done to make it function properly. In order to confirm that the code was working and used in a correct way some results in (Lindblom et al. 2016) were reproduced. Before starting the evaluation of the model, some much-needed optimizations of the code were done, substantially reducing the run time. A sensitivity analysis was done, and the five most sensitive parameters were picked out to be used in the calibration. The calibration improved the total fit of the model to the available measurements, although one of the model outputs could not be calibrated satisfactorily. In short, I found that although there are still problems left to solve before the model can be stated to accurately model the anammox process with MBBR, it appears promising. Most importantly, more measurement data are needed in order to make a proper validation and to do a better calibration.
CONAN

Lower production rate of solids in attached growth moving bed bioreactor (MBBR) systems as compared to conventional activated sludge (AS) systems makes them an attractive choice for municipal wastewater treatment (Ødergaard et al. 1994). However, the production of biologically-produced solids in MBBR systems is currently not well defined and requires additional investigation. Three identical MBBR reactors were operated under the same dissolved oxygen (DO) concentration, influent pH and volume of Anoxkalnes media in two different experimental phases. In the first phase, the hydraulic retention time (HRT) kept constant in three reactors and SALR increased and in the second phase, the SALR was the constant parameter while HRT increased. These two phases were implemented to investigate the effect of variations in HRT and SALR on biologically-produced solids in MBBR reactors. This study demonstrated that HRT and SALR play an important role in settling characteristics of the biologically-produced solids in MBBR systems.

There is an increasing need for tertiary level wastewater treatment in Canada, driven in some cases by both provincial and federal regulation (Canada Gazette, 2012). Tertiary nitrification is the biologically mediated oxidation of nitrogen in the form of ammonia to nitrate following secondary treatment of carbonaceous material (Barnes & Bliss, 1983). The application of tertiary nitrification can prove challenging in the Canadian climate because of the temperature sensitive nature of nitrifiers (Hwang & Oleszkiewicz, 2007). Hence the greater than 1000 lagoon treatment plants currently in operation throughout country are susceptible to the full onslaught of weather effects and as such their nitrification processes become non-existent during the winter months (Delatolla et al., 2011,Hoang et al., 2014). The moving bed biofilm reactor (MBBR) system has been studied and shows promise for continuous nitrification with prolonged exposure to cold temperatures (Hoang et al., 2014). They are marketed as cost effective and low operation intensive upgrade options for existing treatment plants as well as effective stand-alone systems and are currently in operation in many countries worldwide (WEF, 2011). Despite the MBBRs initial development as a nitrification technology, recent research has been focused on COD removal systems. Studies showing that MBBR performance is directly related to surface area loading rates (SALRs) and not carrier type or shape have been performed exclusively on COD removal systems. The influence of MBBR carrier type on system solids production has also been solely studied for COD removal and the principles learnt have been transferred to tertiary nitrification systems without confirmation that they hold true. There is an absence of research on tertiary nitrifying kinetics; the effect of loading and carrier type, the nature of the solids produced and the carrier biofilm characteristics. This study investigated three MBBR carrier types, the K3, M and P Anoxkaldnes carriers in an effort to quantify the effects of carrier type on nitrifying kinetics, biologically – produced solids and the bacterial community at normal and high loading conditions. Four tertiary nitrifying laboratory scale MBBRs were fed with synthetic wastewater and operated at a high loading condition (HLC) with a SALR of 1.89 ± 0.10 g-N/m2•d and a normal loading condition (NLC) with SALR of 0.91 ± 0.1 g-N/m2•d. At both HLC and NLC, results show no difference in the ammonia removal rates obtained by the different carrier types. It was however noticed that stressed operational conditions developed for the P and M carrier at the HLC due to the clogging of carrier pore spaces with biofilm and subsequent reductions in removal efficiency were observed. Despite the fact that larger surface area to volume carriers (such as the M and P) may lead to MBBR designs with smaller footprints and lower operational cost, the study revealed their greater propensity to become clogged under high loading conditions than the smaller surface area carriers (such as the K3 ). In addition the larger surface area carriers demonstrated longer transitional periods from high loading conditions to lower loading conditions. A reduction in effluent total suspended solids (TSS) concentrations and improved solids settleability was observed with the shift from HLC to NLC. These results suggest the avoidance of high loading conditions in tertiary nitrifying MBBR operation. If low loading rates are not achievable then system design may have to consider the incorporation of coagulant use or an advanced solids separation technique to meet effluent solids regulation. Variable pressure scanning electron microscope (VPSEM) images at HLC showed the presence of water mites on the K3 carrier and nematodes and ciliates on the M and P carriers. While NLC images do not show these organisms. VPSEM also measured thicker biofilms during the HLC than the NLC for all carriers. The results demonstrate a difference in the meso-environments and suggest a difference in the micro-environments of the biofilm attached to each carrier. Microbial analysis showed no shifts in the dominant nitrifying species between the loading conditions, as well as no differences in the percent live /dead cell coverage. Nitrosomonas and Nitrospira were identified as the dominant AOB and NOB genera respectively at both the HLC and the NLC. Clear shifts in the microbial populations were observed for specific bacteria; with filamentous bacteria being observed at greater relative abundance at HLC than HLC. The increased relative abundance of filamentous organisms are also associated with the significantly poorer effluent settling characteristics observed at HLC.

The separation of solids from biological wastewater treatment is an important step in the treatment process, as it has a significant impact on effluent water quality. The moving bed biofilm reactor (MBBR) technology is a proven upgrade or replacement wastewater treatment system for carbon and nitrogen removal. However, a challenge of this technology is the characteristics of the effluent solids that results in their poor settlement; with settling being the common method of solids removal. The main objective of this research is to understand and expand the current knowledge on the settling characteristics of MBBR produced solids and the parameters that influence them. In particular, in this dissertation, the impacts are studied of carrier types, biofilm thickness restraint design of carriers, and varying carbonaceous loading rates on MBBR performance, biofilm morphology, biofilm thickness, biofilm mass, biofilm density, biofilm detachment rate, solids production, particle size distribution (PSD) and particle settling velocity distribution (PSVD). With this aim, three MBBR reactors housing three different carrier types were operated with varying loading rates. In order to investigate the effect of carrier geometrical properties on the MBBR system, the conventional, cylindrically-shaped, flat AnoxK™ K5 carrier with protected voids was compared to two newly-designed, saddle-shaped Z-carriers with the fully exposed surface area. Moreover, the AnoxK™ Z-200 carrier was compared to the AnoxK™ Z-400 carrier to evaluate the biofilm thickness restraint design of these carriers, where the Z-200 carrier is designed for greater biofilm thickness-restraint. The Z-200 carrier is designed to limit the biofilm thickness to the level of 200 µm as opposed to 400 µm for the Z-400 carrier. Finally, to investigate the effects of varying carbonaceous loading rates on system removal performance, biofilm characteristics and solids characteristics, further analyses were performed at three different loading rates of 1.5 to 2.5 and 6.0 g-sBOD/m2·d in steady-state conditions. The PSD and the PSVD analyses were combined to relate these two properties. A settling velocity distribution analytical method, the ViCAs, was applied in combination with microscopy imaging and micro-flow imaging to investigate the relation of PSD and settling behaviour of MBBR produced particles. The obtained results have indicated that the carrier type significantly impacted the MBBR performance, biofilm, and particle characteristics. As such, the K5 carrier MBBR system demonstrated a statistically significantly higher carbonaceous removal rate and efficiency (3.8 ± 0.3 g-sBOD/m2·d and 59.9 ± 3.0% sBOD removal), higher biofilm thickness (281.1 ± 8.7 μm), higher biofilm mass per carrier (43.9 ± 1.0 mg), lower biofilm density (65.0 ± 1.5 kg/m3), lower biofilm detachment rate (1.7 ± 0.7 g-TSS/ m2·d) and hence lower solids production (0.7 ± 0.3 g-TSS/d) compared to the two Z-carriers. The Z-carriers' different shape exposes the biofilm to additional shear stress, which could explain why the Z-carriers have thinner and denser biofilm, resulting in higher solids production and lower system performance in comparison with K5. Moreover, the carrier type was also observed to impact the particle characteristics significantly. PSD analysis demonstrated a higher percentage of small particles in the Z-carrier system effluent and hence a significantly lower solids settling efficiency. Therefore, the solids produced in the K5 reactor have shown enhanced settling behaviour, consisting of larger particles with faster settling velocities compared to Z-carriers. This dissertation also investigated the effects of restraint biofilm thickness on MBBR performance by comparing the Z-200 biofilm thickness-restraint carrier to the Z-400 carrier. No significant difference was observed in removal efficiency, biofilm morphology, biofilm density, biofilm detachment rate, and solids production between the Z-200 to the Z-400 carriers. The PSD and the PSVD analyses did not illustrate any significant difference in the particles’ settling behaviour for these two biofilm thickness restraint carriers, indicating that the biofilm thickness-restraint carrier design was not a controlling factor in the settling potential of MBBR produced solids. Finally, this research studied the effect of varying loading rates and demonstrated a positive, strong linear correlation between the measured sBOD loading rate and the removal rate, indicating first-order BOD removal kinetics. The biofilm thickness, biofilm density and biofilm mass decreased when the surface area loading rate (SALR) was increased from 2.5 to 6.0 g-sBOD/m2·d. The solids retention time (SRT) was also shown to decrease by increasing the SALR, where the lowest SRT (1.7 ± 0.1 days) was observed at the highest SALR, with the highest cell viability (81.8 ± 1.7%). Significantly higher biofilm detachment rate and yield were observed at SALR 2.5, with the thickest biofilm and a higher percentage of dead cells. Consequently, a higher fraction of larger and rapidly settling particles was observed at SALR of 2.5 g-sBOD/m2·d, which leads to a significantly better settling behaviour of the MBBR effluent solids. This study expands the current knowledge of MBBR-produced particle characteristics and settling behaviour. A comprehensive understanding of the MBBR system performance and the potential influencing factors on the MBBR produced solids, particle characteristics, and their settleability will lead to optimized MBBR design for future pilot- and full-scale applications of the MBBR.

Textile wastewater often shows high color concentration, containing a large range of organic chemicals, with high chemical oxygen demand as well as hard-degradation materials. Therefore, understanding and developing effective textile industrial wastewater treatment technologies is environmentally important. Different treatments such as biological or physico-chemical processes have been studied to treat textile wastewater. Membrane Bioreactor (MBR) technology has been widely applied in textile wastewater treatment and Moving Bed Biofilm Reactor (MBBR) is a relatively novel technology to treat this type of wastewater. Both of them have some deficiencies and limitations during application. Thus, a MBBR-MBR hybrid system could be an attractive solution to the shortcomings of each treatment process. In this thesis, a hybrid MBBR-MBR system has been designed and applied for the treatment of textile wastewater. Additionally, the feasibility of reusing the treated water in new dyeing processes has been studied. The first step of the thesis work has been the comparative study of the treatment of textile wastewater by three treatment processes, conventional activated sludge (CAS), MBR and MBBR, working under the same operating conditions. The results showed that technically, MBR was the most efficient technology, of which the chemical oxygen demand (COD), total suspended solids (TSS), and color removal efficiency were 91%, 99.4%, and 80%, respectively, with a hydraulic retention time (HRT) of 1.3 days. MBBR, on the other hand, had a similar COD removal performance compared with CAS (82% vs. 83%) with halved HRT (1 day vs. 2 days) and 73% of TSS removed, while CAS had 66%. Economically, MBBR was a more attractive option for an industrial-scale plant since it saved 68.4% of the Capital Expenditures (CAPEX) and had the same Operational Expenditures (OPEX) as MBR. The MBBR system also had lower environmental impacts compared with CAS and MBR processes, since it reduced the consumption of electricity and decolorizing agent with respect to CAS. According to the results, the water treated by the MBBR system was reused to make new dyeings and the quality of new dyed fabrics was within the acceptable limits of the textile industry. Combined with the theory and experimental results, a hybrid MBBR-MBR reactor was designed and applied in textile wastewater treatment. The MBBR-MBR system achieved reducing the HRT to 1 day, which is very promising in textile industry comparing with conventional biological treatment. The removal efficiency of COD reached 93%, which is almost the maximum for a biological process treating this type of wastewater, as well as the color removal performance, which achieved 85%. Additionally, 99% of the TSS were removed due to the filtration. Furthermore, new dyeing processes reusing the treated water were performed. Color differences between new dyed fabrics and reference fabrics were found within the general requirement of textile industry (DECMC(2:1) < 1). Additionally, based on the experimental results in the pilot plant, an economic study and LCA analysis were carried out to evaluate the economic and environmental feasibility of the implementation of the hybrid MBBR-MBR on an industrial scale. Economically, MBBR-MBR had lower CAPEX and OPEX than CAS process due to lower effluent discharge tax and the decolorizing agent saved. The result of Net Present Value (NPV) and the Internal Rate of Return (IRR) of 18% suggested that MBBR-MBR is financially applicable for the implantation into industrial scale. The MBBR-MBR system also had lower environmental impacts compared with CAS process in the LCA study, especially in some categories, such as the Climate change, Human Health, Marine eutrophication, and ecotoxicity categories, thanks to the high quality of the effluent treated by MBBR-MBR and the avoiding of using extra decolorizing agent, a compound based on a quaternary amine.
Como uno de los sectores más antiguos y complejos dentro de las industrias manufactureras, la industria textil consume grandes cantidades de agua y produce grandes volúmenes de aguas residuales durante su producción. Las aguas residuales textiles presentan a menudo una elevada coloración, contienen una amplia gama de productos químicos orgánicos, con una alta demanda química de oxígeno, así como materiales con poco degrabilidad. Por lo tanto, comprender y desarrollar tecnologías de tratamiento de aguas residuales industriales textiles eficaces es muy importante ambientalmente. Se han desarrollado diferentes tratamientos, tanto procesos biológicos como físico-químicos para la depuración de aguas residuales textiles. La tecnología de Bioreactor de membranas (conocida por su acrónimo en inglés como MBR) se ha aplicado ampliamente en el tratamiento de aguas residuales textiles, mientras el Reactor de biofilm de lecho móvil (conocido por sus iniciales en inglés como MBBR) es una tecnología relativamente nueva para tratar este tipo de aguas residuales. Ambos muestran algunas deficiencias y limitaciones durante su aplicación. Por lo cual, un sistema híbrido MBBR-MBR podría ser una solución atractiva a los inconvenientes de cada uno de estos dos procesos individuales. En esta tesis se ha diseñado y aplicado un sistema híbrido MBBR-MBR para el tratamiento de aguas residuales textiles. Adicionalmente, se ha estudiado la viabilidad de reutilizar el agua tratada en nuevos procesos de tintura. El primer paso del trabajo desarrollado en la tesis ha sido el estudio comparativo del tratamiento de aguas residuales textiles mediante tres procesos de tratamiento, fangos activados convencionales (CAS), MBR y MBBR, trabajando en las mismas condiciones de funcionamiento. El rendimiento de cada proceso ha sido investigado y comparado desde una perspectiva técnica, económica y ambiental. Los resultados mostraron que, técnicamente, el MBR era la tecnología más eficiente, con valores de eliminación de demanda química de oxígeno (COD), sólidos en suspendidos totales (TSS) y de color de 91%, 99,4% y 80%, respectivamente, a un tiempo de retención hidráulica (HRT) de 1,3 días. MBBR, por otro lado, tuvo un rendimiento de eliminación de COD similar en comparación con CAS (82% frente a 83%), sin embargo reducía a la mitad el HRT (1 día frente a 2 días) y eliminaba un 73% de TSS , mientras que CAS tenía el 66%. Económicamente, MBBR era una opción más atractiva para una planta a escala industrial, ya que ahorraba 68,4% de los gastos de capital (conocidos por sus iniciales en inglés como CAPEX) y vi tenía los mismos gastos operativos (conocidos por sus iniciales en inglés como OPEX) que MBR. El sistema MBBR también tuvo menores impactos ambientales en comparación con los procesos CAS y MBR, ya que redujo el consumo de agente decolorante con respecto a CAS y de electricidad con respecto a MBR. Según los resultados de los análisis económicos y de Análisis de Ciclo de Vida (conocido por sus iniciales en inglés como LCA), el agua tratada por el sistema MBBR se reutilizó para realizar nuevas tinturas comprobando que la calidad de los nuevos tejidos teñidos se encontraba dentro de los límites aceptables de la industria textil. Combinado con la teoría y los resultados experimentales, se diseñó y operó un reactor híbrido MBBR-MBR para el tratamiento de aguas residuales textiles. El sistema MBBR-MBR logró reducir la HRT a 1 día, lo que es muy prometedor en la industria textil, en comparación con el tratamiento biológico convencional. La eficiencia de remoción de COD alcanzó el 93%, que es cercano al máximo para un proceso biológico de tratamiento de este tipo de aguas residuales. Así como el desempeño de remoción de color, que alcanzó el 85%. Además, se eliminó el 99% de los TSS debido a la filtración. A continuación, se realizaron nuevos procesos de tintura reutilizando el agua tratada. La calidad de los nuevos tejidos teñidos con agua tratada se comparó con los tejidos de referencia. Las diferencias de color entre los tejidos nuevos teñidos y los tejidos de referencia se encontraron dentro del requisito general de la industria textil (DECMC (2: 1) <1). La reutilización del agua tratada en nuevos procesos de tintura es beneficiosa tanto para la industria como para el medio ambiente ya que el sector textil es un consumidor intensivo de agua en sus procesos de tintura y acabado. Adicionalmente, con los resultados experimentales en la planta piloto, se realizó un estudio económico y un análisis de LCA para evaluar la viabilidad económica y ambiental de la implementación del sistema híbrido MBBR-MBR a escala industrial. Económicamente, MBBR-MBR tuvo los gastos de CAPEX y OPEX más bajos que CAS debido a las menores tasas de vertido de aguas residuales industriales y al ahorro de agente decolorante. El resultado del Valor Actual Neto (conocido por sus iniciales en inglés como VPN) y la Tasa Interna de Retorno (conocida por sus iniciales en inglés como TIR) del 18% sugirió que MBBR-MBR es financieramente viable para la implantación a escala industrial. El sistema MBBR-MBR también tuvo menores impactos ambientales en comparación con el proceso CAS en el análisis del ciclo de vida (LCA), especialmente en categorías, como cambio climático, salud humana, eutrofización marina y ecotoxicidad, gracias a la alta calidad del efluente tratado con MBBR-MBR y a evitar el uso de agente decolorante, que es un compuesto sintetizado a base de una amina cuaternaria.
Com un dels sectors més antics i complexos dins de les indústries manufactureres, la indústria tèxtil consumeix grans quantitats d'aigua i produeix grans volums d'aigües residuals durant la seva producció. Les aigües residuals tèxtils presenten sovint una elevada coloració, contenen una àmplia gamma de productes químics orgànics, amb una alta demanda química d'oxigen, així com materials poc degrabilidables. Per tant, comprendre i desenvolupar tecnologies de tractament d'aigües residuals industrials tèxtils eficaces és molt important ambientalment. S'han desenvolupat diferents tractaments, tant processos biològics com físic-químics per al tractament d'aigües residuals tèxtils. La tecnologia de Bioreactor de membrana (coneguda pel seu acrònim en anglès, MBR) s'ha aplicat àmpliament en el tractament d'aigües residuals tèxtils, mentre que el Reactor de biofilm de llit mòbil (conegut amb les seves inicials en anglès com MBBR) és una tecnologia relativament nova per tractar aquest tipus d'aigües residuals. Tots dos mostren certes deficiències i limitacions durant la seva aplicació. Per tant, un sistema híbrid MBBR-MBR podria ser una solució atractiva als inconvcenients de cadascun d’aquests dos processos individuals. En aquesta tesi s'ha dissenyat i operatt un sistema híbrid MBBR-MBR per al tractament d'aigües residuals tèxtils. Addicionalment, s'ha estudiat la viabilitat de reutilitzar l'aigua tractada en nous processos de tintura. El primer pas del treball desenvolupat a la tesi ha estat l'estudi comparatiu del tractament d'aigües residuals tèxtils mitjançant tres processos de tractament, fangs activats convencionals (CAS), MBR i MBBR, treballant en les mateixes condicions de funcionament. El rendiment de cada procés ha estat investigat i comparat des de les perspectives tècnica, econòmica i ambiental. Els resultats van mostrar que, tècnicament, MBR era la tecnologia més eficient, amb valors d’eliminació de la demanda química d'oxigen (COD), de sòlids suspesos totals (TSS) i de color de 91%, 99,4% i 80 %, respectivament, amb un temps de retenció hidràulica (HRT) de 1,3 dies. MBBR, d'altra banda, va tenir un rendiment d'eliminació de COD similar en comparació amb CAS (82% enfront de 83%), per contra aconseguia reduir a la meitat el HRT (1 dia enfront de 2 dies) i eliminava el 73% de TSS , mentre que CAS tenia el 66%. Econòmicament, MBBR era una opció més atractiva per a una planta a escala industrial, ja que estalviava el 68,4% de les despeses de capital (conegut amb les seves inicials en anglès com CAPEX) i tenia les mateixes despeses operatives (conegut amb les seves inicials en anglès com OPEX) que MBR. El sistema MBBR també va tenir menors impactes ambientals en comparació amb els processos CAS i MBR, ja que reduia el consum d’agent decolorant respecte a CAS i el consum d'electricitatrespecte a MBR i. Segons els resultats de les anàlisis econòmiques i de Anàlisi de Cicle de Vida (conegut amb les seves inicials en anglès com LCA), l'aigua tractada pel sistema MBBR es va seleccionar per a reutilitzar en noves tintures, comprovant quela qualitat dels nous teixits tenyits es trobava dins dels límits acceptables de la indústria tèxtil. Combinat amb la teoria i els resultats experimentals, es va dissenyar i operar un reactor híbrid MBBR-MBR per al tractament d'aigües residuals tèxtils. El sistema MBBR-MBR va aconseguir reduir la HRT a 1 dia, el que és molt prometedor en la indústria tèxtil en comparació amb el tractament biològic convencional. L'eficiència de remoció de COD va arribar al 93%, que és gairebé el màxim per a un procés biològic de tractament d'aquest tipus d'aigües residuals, així com el rendiment d’eliminació de color, que va arribar al 85%. A més, es va eliminar el 99% dels TSS gràcies a la filtració. A continuació, es van realitzar nous processos de tintura reutilitzant l'aigua tractada. La qualitat dels nous teixits tenyits amb aigua tractada es va comparar amb els teixits de referència. Les diferències de color entre els teixits nous tenyits i els teixits de referència es van trobar dins del requisit general de la indústria tèxtil (DECMC (2: 1) <1). La reutilització d'aigua tractada en nous processos de tintura és beneficiosa tant per a la indústria com per al medi ambient ja que el sector tèxtil és un consumidor intensiu d'aigua en els seus processos de tintura i acabat. Addicionalment, amb els resultats experimentals a la planta pilot, es va realitzar un estudi econòmic i una anàlisi de LCA per avaluar la viabilitat econòmica i ambiental de la implementació del sistema'híbrid MBBR-MBR a escala industrial. Econòmicament, MBBR-MBR va tenir despeses de CAPEX i OPEX més baixes que CAS degut a les menors taxes d’abocament d’aigües residuals industrialsi a l'estalvi d'agent decolorant. El resultat del valor actual net (conegut amb les seves inicials en anglès com VPN) i la Taxa Interna de Retorn (conegut amb les seves inicials en anglès com TIR) del 18% va suggerir que MBBR-MBR és financerament aplicable per a la implantació a escala industrial. El sistema MBBR-MBR també va tenir menors impactes ambientals en comparació amb el procés CAS en LCA, especialment en categories, com canvi climàtic, salut humana, eutrofització marina i ecotoxicitat, gràcies a l'alta qualitat de l'efluent tractat amb MBBR-MBR i al fet d’evitar l'ús de l’agent decolorant , que és un compost sintetitzat a partir d'una amina quaternària.
Enginyeria ambiental

Wastewater treatment plays significant role in the environmental protection. The process has direct impact on quality of air and water. All treated sewage reaches fresh water reservoirs as well as gasses escaping from the process are emitted to the atmosphere. Main aim of the thesis is to determine N2O emissions from partial nitritation/Anammox (deammonification process) in one-stage system applied in MBBR technology. Whole project was operated successfully on two pilot-scale reactors parallel, fed by the same reject water. Both reactors were filled to capacity of 200 L each, where 40% of the working volume was fulfilled by Kaldnes carriers suspended in liquid by mechanical stirrer. First reactor (R1) presented strategy of intermittent aeration with ratio (R=1/3) and stable DO concentration at amount of 1.5 mg O2/L, whereas second one (R2) operated in constant aeration with variable values of dissolved oxygen which differ in range of 1.0-2.5 mg O2/L. Every week analyses of ammonium and nitrogen forms were carried out in influent and effluent by Hach-Lange cuvettes. Results of measurements showed high NH4+-N removal efficiency of approximately 95% for R1 reactor and 86% for R2. During the process, the continuous measurement of nitrous oxide in gaseous and liquid phase was performed by Teledyne data logger and Unisense microsensor. Measurements during 4 months resulted in assessment of nitrous oxide emission tendency dependent on aeration system. The result from reactor R1 showed that 1.0-2.4% of N-load was emitted as N2O to the atmosphere, and 0.05-0.28% was released as dissolved N2O in outgoing water. Regarding reactor R2 tendency of nitrous oxide production is similar. Estimated emission of N2O in gaseous phase in reactor R2 is 1.4-2.0% of nitrogen load and 0.02-0.39% in liquid phase. All gathered results are shown in the appendix of the paper.

Kläder och textilier produceras och konsumeras i allt högre grad med stor påverkan på miljö, klimat och jordens resurser som följd. En attraktiv lösning på det är återvinning av kläder, vilket företaget re:newcell gör. Detta är en förstudie med syfte att undersöka vilka reningsmetoder re:newcell skulle kunna implementera för att förbättra sin vattenreningsprocess i framtiden. Tre ämnen vars halter i nuläget inte reduceras i reningen valdes ut till studien: nonylfenol, bromerade flamskyddsmedel och sulfat. En litteraturstudie kring dessa ämnen och möjliga reningsmetoder resulterade i att tre lämpliga reningsmetoder valdes ut till studien: ozonering, biologisk rening och jonbyte. En försöksplan utformades med målen att ta reda på (1) hur tidigare rapporterade ozondoser påverkade nonylfenolhalten i re:newcells vatten, (2) hur stor andel TOC (Total Organic Carbon) en MBBR (moving body bioreactor) kunde reducera och (3) ifall PBDE (bromerade flamskyddsmedel) och sulfat var möjliga att bryta ner med i en MBBR, (4) hur stort jonbytarfilter som skulle krävas i re:newcells process för att reducera sulfathalten samt (5) i vilken ordning reningsstegen bör implementeras i framtida reningsprocesser. Ozoneringsförsök utfördes på re:newcells laboratorium i Kristinehamn med totalt fem olika ozondoser. En biologisk MBBR utformades i laboratorium på Karlstad Universitet, där två olika uppehållstider testades för reducering av flamskyddsmedel, sulfat och TOC. Beräkningar på jonbytarfilter utfördes teoretiskt. En ozondos på 0,45 mgO3/mgCOD gav en reducering på ca 31 % och 0,75 mgO3/mgCOD gav 78 % reducering vid en nonylfenolhalt på 1100 mg/L. Resultaten från MBBR visar att bakterier trivs i re:newcells vatten och att de kunde reducera TOC med ca 50 %. Däremot kunde ingen reducering av sulfat uppmätas, vilket tyder på att ingen anaerob zon har uppstått. Halten av PBDE reducerades med ca 90 % med en uppehållstid på 45 h i MBBR, men om det beror på nedbrytning eller adsorption till slammet är inte fastställt. Resultaten från beräkningen på jonbytarfiltret visade att filtret behöver vara 5,7-15 m3 vid regenerering en gång per dygn i re:newcells nuvarande pilotskaliga process. Denna metod anses därmed inte vara en lämplig för sulfatreducering. Den framtida reningsprocessen föreslås starta med MBBR och efterföljande sedimentering, följt av kemfällning, sedimentering/flotation, sandfilter, ozonering och sist aktivkolfilter, men vidare studier rekommenderas rörande vilken ordning reningsstegen bör implementeras för optimal effekt. Vidare studier kring vilken ozondos som krävs och vilken uppehållstid som är optimal i MBBR föreslås också.
Clothes and textiles are increasingly produced and consumed causing a major impact on the environment, the climate and the earth's resources. One solution to the problem is to recycle clothes that are no longer used, which is what the company re:newcell does. This is a feasibility study aimed at investigating what purification methods re:newcell could implement to improve their water purification process in the future. Three substances not currently purified sufficiently were selected for the study: nonylphenol, brominated flame retardants and sulfate. A literature review on these substances and possible purification methods for them resulted in that the following methods were selected for the study: ozonation, biological purification and ion exchange. An experimental plan was developed with the aim of finding out (1) how previously reported ozone doses affected the nonylphenol content in re:newcell's water, (2) how much TOC an MBBR (moving body bioreactor) could reduce, (3) and whether the levels of brominated flame retardants and sulphate were possible to reduce in it,  (4) the required size of the ion exchange filter in re:newcells process to reduce sulfateand (5) the order in which the purification steps should be implemented in future purification processes. Ozonation experiments were carried out at re:newcell's laboratory in Kristinehamn with a total of five different ozone doses tested. A biological MBBR was designed in a laboratory at Karlstad University, where two different hydraulic retention times were tested for reducing flame retardants, sulfate and TOC. Calculations on ion exchange filters were performed theoretically. An ozone dose of 0.45 mgO3/mgCOD produced a reduction of about 31% and 0.75 mgO3/mgCOD produced a 78% reduction at a nonylphenol content of 1100 µg / L The results from MBBR showed that bacteria thrived in re:newcell´s water and that they can reduce TOC by about 50 %. However, reduction of sulfate could be measured, suggesting that no anaerobic zone has occured. The content of PBDE was reduced by about 90% with a hydraulic retention time of 45 hours in MBBR, but whether it is due to degradation or adsorbation to the sludge is not determined. The calculation regarding the ion exchange filter show that the filter needs to be 5,7-15 m3 when regenerated once a day in re:newcell's current pilot scale process this method is therefore not considered appropriate  for sulfate reduction for re:newcell. The future purification process is proposed to start with MBBR and subsequent sedimentation, followed by chemical precipitation, sedimentation / flotation, sand filter, ozonation and last activated carbon filter, but further studies are recommended regarding which order the purification steps should be implemented for optimal effect. Further studies on which ozone dose is required and which residence time is optimal in MBBR are also suggested.

Nitrification is currently the most common means of ammonia removal from wastewaters in temperate climates. In conventional suspended growth systems operating in northern climate regions, nitrification completely ceases at temperatures below 8°C. This is a considerable concern in passive treatment systems where wastewater temperatures can reach as low as 1°C for extended periods in the winter months. There is evidence biofilm technologies have the ability to nitrify at low temperatures, however, the literature is missing an understanding of low temperature nitrification and the subsequent impacts during seasonal changes. Additionally, there is an urgent need to gain a fundamental knowledge of the interplay between nitrifying performance optimization, biofilm morphology and the microbiome. This research aims to fill these needs using nitrifying moving bed biofilm reactors (MBBRs) at the lab and pilot scale. This research concluded the most important factor determining MBBR carrier selection is a combination of surface area and pore space size. Although high surface area to volume carriers are attractive, the propensity to clog at high loading rates significantly decreases the removal rates. The viability of the biomass and ammonia oxidizing bacterial communities were not significantly changed, indicating the ammonia removal rates were reduced due to loss of surface area in the clogged carriers. Operation at 1°C demonstrated significant rates of nitrification can be attained and stable for extended periods of operation. This study developed the first kinetic curve at 1°C with a maximum removal rate of 0.35 gN/m2·d. The performance of the post carbon removal nitrifying MBBR systems were shown to be enhanced at 1°C by an increase in the viable embedded biomass as well as thicker biofilm. This effectively increased the number of viable cells present during low temperature operation, which partially compensated for the significant decrease in rate of ammonia removal per nitrifying cell. At all studied loading rates at 1°C, the ammonia oxidizing bacteria were primarily in the family Nitrosomonadaceae (greater than 95 percent abundance of AOB population) and the nitrite oxidizing bacteria were primarily the genus Nitrospira (greater than 99 percent abundance of NOB population). Operation at 20°C demonstrated high rates of removal in high loaded condition and robustness in extreme low loaded conditions. In both high loaded and extreme low loaded conditions the viability of the nitrifying biomass was sustained, with the family Nitrosomonadaceae as the primary ammonia oxidizing bacteria and the genus Nitrospira as the primary nitrite oxidizing bacteria. In extreme low loaded conditions and as well during start-up phases there are high prevalence of bacteria not directly related to the nitrification process. Their presence however indicates a dynamic process with changes in microbial composition within the biofilm matrix in response to varying conditions. Change in microbial composition likely helps stabilize and maintain the biofilm matrix enhancing process robustness in the temperate climates. The new knowledge gained in this research optimizes the operation of nitrifying MBBR systems and elucidates the impacts of operational conditions on the biofilm and microbial community of nitrifying MBBR systems to further our understanding of nitrifying attached growth treatment technologies. The results of this study are anticipated to be used to design the first MBBR treatment system for year round ammonia removal in passive treatment systems located in northern climate regions.

Discharging cheese production wastewater with high concentrations of organics and nutrients is detrimental to receiving aquatic systems, as the release of these deleterious substances cause oxygen depletion, and eutrophication respectively. On-site treatment of cheese production wastewater requires the removal of high concentrations of organics and nutrients with a small land footprint to meet regulations. There is therefore a critical need for compact, high-rate, cost-effective wastewater technologies such a as the moving bed biofilm reactor (MBBR). Although MBBR systems have been well established for carbon and nitrogen removal, to date only a limited number of studies have achieved enhanced biological phosphorous removal in sequencing batch moving bed biofilm reactor (SB-MBBR) systems, and only for municipal-strength wastewater. Operating SB-MBBR systems under sequencing batch mode enables the reactor operation to be well synced to the fluctuating influent concentrations and flow characteristics of cheese production wastewaters. Furthermore, cycling between anaerobic and aerobic conditions can be achieved in a single sequencing batch reactor, which can promote the proliferation of poly-phosphate accumulating organisms. The SB-MBBR is studied in this research for the removal of carbon, nitrogen, and phosphorous from cheese production wastewaters. Specifically, the effects of anaerobic staging time, aeration rate, enhanced aerobic operation, and adding a second reactor in series was studied by analyzing the kinetics, biofilm characteristics, and microbiome. Extending the anaerobic staging time was shown to achieve aerobic soluble chemical oxygen demand removal rates of 92.5±2.8 g·m⁻²d⁻¹, by selecting for a thinner biofilm with, with a lower biofilm dry-density and a more rough biofilm surface, and therefore likely a biofilm with an enhanced mass transport. A significant shift in the microbiome was observed with longer anaerobic staging times and lower aeration, whereby possible putative poly-phosphate accumulating organisms including Brachymonas, and Dechloromonas were selected for in greater relative abundances compared to anaerobic bacteria. The total phosphorous removal in the possibly resulted from enhanced biological phosphorous removal, supported by the high abundance of putative poly-phosphate accumulating organisms (43.1±8.4%), which dominated the biofilms in the SB-MBBRs with 120 and 168 minute anaerobic staging times. Finally, total ammonia nitrogen oxidation was achieved through partial nitritation with a two reactor in series configuration with a removal rate of 1.07±0.05 g-N·m⁻²d⁻¹. Two SB-MBBRs operated in series was shown to be the superior strategy for achieving TAN compared to a single SB-MBBR with extended aerobic operation. By operating two SB-MBBRs in series, competition between autotrophic nitrifiers and heterotrophs is averted, and AOB proliferate in the biofilm, achieving TAN oxidation. Since TAN oxidation is likely achieved through partial nitrification, the SB-MBBR technology may be incorporated in a deammonification treatment train. The overall study presents novel information for the SB-MBBR design and operation, along with biofilm and microbiome fundamental findings that will guide future pilot- and full-scale applications of the SB-MBBR to treat cheese production wastewater.

The pulp and paper mill requires a lot of water during the production. Stora Enso Skoghall requires about 33m3 of water for 2204 lb produced carbon or paper. Before the wastewater returns to the recipient, the water must be purified from organic material. Organic material is naturally found in wood, and if a high level of organic material is added to the recipient it will lead to deficiency of oxygen in lakes. In order to avoid deficiencies of oxygen in lakes, the wastewater must go through a biological treatment, Stora Ensos biological treatment is consisting a long-term aerated active sludge, LAS, which is similar to a large pond. During a period, Stora Enso Skoghall constructed a pre-treatment step fort their LAS which is a Moving Bed Biofilm Reactor, MBBR. Stora Enso has been struggling to aerate the wastewater in the LAS, which has affected the production of the industry badly. The purpose of building the MBBR is to facilitate the LAS, in order to deliver full production. The biological treatment requires a lot of energy to operate the aeration system, about 50 percent of the total energy demand for a treatment plant goes to the biological treatment.   The purpose of this study is to examine the impact on the LAS if a MBBR-process is connected as a pre-treatment step. The aim of this study is to examine how the new biological treatment effects the energy demand considering aeration, compared to before the MBBR was connected. Wastewater samples were collected at Stora Enso Skoghall and taken to a laboratory at Karlstads University for analysis and tests. The wastewater samples have been studied regarding its content of TOC and how it affects the possibility of aerating the water. The a- and b-values, and as well the theoretical oxygen demand, were experimentally determined in cylinder aerators that contains 30 liters. The energy use for aeration of the MBBR and the LAS has been estimated. In order to compare if the new biological treatment effects the ability of purification in the existing LAS and if the energy demand changes, wastewater samples were taken before and after the MBBR was connected.   The result of this study shows that the MBBR has a positive impact on the existing LAS at Stora Enso Skoghall. There is a higher reduction of COD and the oxygen uptake capacity is better in the LAS, compared to before the MBBR was connected as a pre-treatment step. The total energy demand has increased with 58 percent, compared to the results before the MBBR were connected. The wastewater from the CTMP production contains high levels of TOC. It contains high levels of surfactants and high ionic strength, which usually worsen the ability of aeration. The flow into the MBBR contains mainly wastewater from the CTMP and the aeration tests showed that only 1-6 percent of the oxygen dissolved in it. As a result, the estimated energy demand remains very high. In conclusion, with the new biological treatment system the industry can now deliver full production of pulp and cardboard, while the LAS gets enough oxygen to effectively purify the wastewater. The MBBR relives the LAS through reduce the right amount of COD so the LAS can aerate the wastewater more easily. Moreover, the total energy demand of the biological treatment has increased when it comes to aerate the wastewater due to the fact that the production of pulp and cardboard has increased with 46 percent.

New federal regulations with regards to ammonia in wastewater effluent discharge will require over 1000 existing wastewater treatment facilities to be upgraded. Although biological treatment is the most common and economical means of wastewater ammonia removal, nitrification rates can be completely impeded at cold temperatures. Moving bed biofilm reactors (MBBR) have shown promise as an upgrade nitrifying unit at pilot-scale and full-scale applications with respect to low temperature nitrification. MBBR technologies offfer the advantages of less space requirement, utilizing the whole tank volume, no sludge recycling, and no backwashing, over other attached growth systems. Two laboratory MBBRs were used in this study to investigate MBBR nitrification rates at 20deg.C, after long-term exposure to 1deg.C, and at the kinetic threshold temperature of 5deg.C. Furthermore, the biologically produced solids from the MBBR system 20deg.C and after long-term exposure to 1deg.C, and the Arrhenius temperature correction models used to predict nitrification rates after long-term exposure to 1deg.C. The nitrification rates at 1deg.C over a four month exposure period as compared to the rate at 20deg.C were 18.7 + 5.5% and 15.7 + 4.7% for the two reactors. The nitrification rate at 5deg.C was 66.2 + 3.9% and 64.4 + 3.7% compared to the rate measured at 20deg.C for reactors 1 and 2, respectively, and as such was identified as the kinetic temperature threshold. The quantity of solids detached from the nitrifying MBBR biocarriers was low and did not vary significantly at 20deg.C and after long-term exposure to 1deg.C. Lastly, a temperature correction model based on exposure time to cold temperatures, developed by Delatolla et al. (2009) showed a strong correlation to the calculated ammonia removal rates relative to 20deg.C following a gradual acclimatization period to cold temperatures. Biofilm morphology along with biomass viability at various depths in the biofilm were investigated using variable pressure electron scanning microscope imaging (VPSEM) and confocal laser scanning microscope (CLSM) imaging in combination with viability live/dead staining. The biofilm thickness along with the number of viable cells showed significant increases after long-term exposure to 1deg.C while the dead cell coverage did not show significant increases after long-term exposure to 1deg.C while the dead cell coverage did not show significant changes. Hence, this study observed higher cell activities at warm temperatures and a slightly greater quantity of biomass with lower activities at cold temperatures in nitrifying MBBR biofilms. Using DNA sequencing analysis, 'Nitrosomonas' and 'Nitrosospira' (ammonia oxidizers)as well as 'Ntrospira' (nitrite oxidizer) were identified in which no population shift was observed during 20deg.C and after long-term exposure to 1deg.C. Furthermore, a number of non-nitrifiers were identified int he biofilm during warm and cold temperatures presenting the possibility that their presence may have provided some form of protection to the nitrifiers during long-term temperature exposure.

Moving bed biofilm reactors (MBBRs) have been used effectively to reach low nutrient levels in northern Europe for nearly 20 years at cold temperatures. A relatively new technology to the US, the MBBR has most typically been used in a post-denitrification configuration with methanol for additional nitrate removal. Methanol has clearly been the most commonly used external carbon source for post-denitrification processes due to low cost and effectiveness. However, with the requirement for more US wastewater treatment plants to reach effluent total nitrogen levels approaching 3 mg/L, alternative electron donors could promote more rapid MBBR startup/acclimation times and increased cold weather denitrification rates. Bench-scale MBBRs evaluating four different electron donor sources, specifically methanol, ethanol, glycerol, and sulfide (added as Na2S), were operated continuously at 12 °C, and performance was monitored by weekly sampling and insitu batch substrate limiting profile testing. Ethanol and glycerol, though visually exhibited much higher biofilm carrier biomass content, performed better than methanol in terms of removal rate (0.9 and 1.0 versus 0.6 g N/m²/day.) Maximum denitrification rate measurements from profile testing suggested that ethanol and glycerol (2.2 and 1.9 g N/m²/day, respectively) exhibited rates that were four times that of methanol (0.49 g N/m²/day.) Sulfide also performed much better than any of the other three electron donors with maximum rates at 3.6 g N/m²/day and with yield (COD/NO₃-N) that was similar to or slightly less than that of methanol. Overall, the yield and carbon utilization rates were much lower than expected for all four electron donors and much lower than previously reported; indicating that there could be advantages for attached growth versus suspended growth processes in terms of carbon utilization rates. The batch limiting NO₃-N and COD profiles were also used to find effective K_s values. These kinetic parameters describe NO₃-N and COD limitations into the biofilm, which affect the overall denitrification rates. Compared to the other electron donors, the maximum rate for methanol was quite low, but the estimated K_s value was also low (0.4 mg/L N). This suggests high NO₃-N affinity and low mass transfer resistance. The other three electron donors estimated higher K_s values, indicating that these biofilms have high diffusion resistance. Biofilm process modeling is more complex than for mechanistic suspended growth, since mass transfer affects substrate to and into the biofilm. Simulating the bench-scale MBBR performance using BioWin 3.0, verified that μ_max and boundary layer thickness play key roles in determining rates of substrate utilization. Adjustments in these parameters made it possible to mimic the MBBRs, but it is difficult to determine whether the differences are due to the MBBR process or the model.
Master of Science

L'objectif de cette thèse est d'évaluer le concept d'un dispositif intégré comprenant un bioréacteur à biofilm fluidisé bio-augmenté, couplé à une membrane de nanofiltration de type polyelectrolyte multicouche, destiné à éliminer les micropolluants en traitement tertiaire des eaux usées domestiques, traitées conventionnellement. Les résultats montrent que, pour des micropolluants ciblés, chacun des procédés est efficace comme traitement tertiaire. Les mécanismes biologiques et de rétention membranaires sont explicités. Cependant des challenges restent à relever en particulier pour l'étape de bio augmentation (survie et implantation de la souche apportée) pour une exploitation de cette étape. D'autre part, des investigations plus poussées sont nécessaires à l'élaboration d'une membrane fiable et robuste. Un tel procédé couplé MBBR-NF pourra alors être entièrement justifié dans le contexte d'une élimination performante de micropolluants ciblés. Il aura toute sa place dans le panel des technologies vertes pour la préservation de l'environnement
This thesis aims at answering whether the concept of an integrated layout comprised of a coupled "bioaugmented moving bed biofilm reactors (bMBBRs) - polyelectrolyte multilayer (PEM)-based nanofiltration (NF) membrane" can be considered as a promising technology to eliminate target MPs from conventionally-treated municipal wastewater. Results presented herein indicate that each given component of the layout is efficient in the tertiary removal of MPs. Still, several challenges ahead of the process bioaugmentation (such as the survival and maintenance of inoculated strains) must be in-depth studied to find convenient operating solutions. On the other hand, further investigations are definitely needed to achieve a robust PEM-based membrane as a long-lasting technology. Even though a coupled bMBBR-NF system for enhanced MPs removal can be experimentally justified is, however, practically questionable. "The tale of bMBBR-NF" deserves much more scientific endeavors as plenty of environmental considerations are placed in, whereby achieving a future Green technology will not be far from our expectation

O tratamento do lodo gerado em estações de tratamento de água para abastecimento (ETAs) é uma questão a ser equacionada em todo o território nacional. O tratamento desses lodos em estações de tratamento de esgoto (ETEs) é uma alternativa a ser estudada, pois pode levar a uma solução eficaz e de custos reduzidos se compararmos aos custos de implantação e operação de um sistema de tratamento de lodos nas próprias ETAs. O recebimento de lodo de ETAs em ETEs é feito em algumas ETEs dos Estados Unidos, porém no Brasil ainda são escassos estudos específicos para sanar as questões técnicas envolvidas tanto na etapa aeróbia quanto na anaeróbia. O sistema de tratamento de esgotos por lodos ativados utilizando mídia plástica como meio suporte ao crescimento microbiológico é outro atrativo ao recebimento de lodo de ETA em uma ETE, visto que estudos demonstram que este tipo de variante é capaz de tratar maior carga orgânica, sem sofrer qualquer inibição de processo. O presente estudo avaliou o recebimento de até 400 mg de SST de lodo de ETA por litro de esgoto em um sistema utilizando mídia plástica como meio suporte. O lodo de ETA utilizado foi proveniente de sistemas que utilizaram sais de Ferro e de Alumínio em seus processos. Não foi observada qualquer inibição no processo aeróbio quanto à remoção de matéria orgânica ou nitrogenada com o recebimento de lodo de ETA em qualquer concentração e operando um sistema com mídia plástica. A carga de DBO5,20 aplicada ao reator biológico ficou entre 1,7 a 15,3 gDBO5,20/m²/dia, e a concentração média da DBO 5,20 no efluente final esteve em todo o período do experimento em 34 mg/L. Com a utilização da mídia plástica o processo de nitrificação teve taxas de remoção passando de 0,9 gNKT/m²/dia para 1,7 gNKT/m²/dia, portanto aumento de 95%. A avaliação do lodo gerado no decantador primário da ETE Piloto demonstra que houve alteração em sua composição, principalmente na relação de SV/ST e o aumento na concentração de metais, principalmente o elemento Ferro. Estas características podem levar à inibição o processo anaeróbio. O teste de Atividade Metanogênica Especifica (AME) realizada com dosagens de 0,4 g e 0,8 g de ST de lodo de ETA demonstra que há inibição da metanogênese para concentrações acima de 0,4 g de ST. A concentração na qual não se observou efeito negativo corresponde a 10% da quantidade mássica que o digestor anaeróbio foi alimentado. Porém o teste de AME reproduz toxicidade aguda, não considerando a possível adaptação que pode ocorrer ou mesmo demonstrar que um esgoto que, em primeira análise é considerado biodegradável, tem na realidade toxicidade crônica. A operação do sistema utilizando mídia plástica levou a uma redução na produção de lodo na ordem de 57%. Antes da maturação do biofilme a produção era de 0,19 g SSV/g DQO removida e passou para 0,09 g SSV/g DQO removida.
An issue to be taken into account, regarding the continental size of the country is the sludge treatment generated in water treatment plants (WTPs). The treatment of the aforementioned sludge which is held in water treatment plant (WWTP) is a valid alternative considering its costs and efficacy as opposed to the budgetary considerations for the sludge treatment in the WTPs alone. The recipience of the sludge from WTP into WWTPs, is done by some North Americans WWTPs, in Brazil, nonetheless, such specific studies are of short supply to heal the technical questions regarding both the anaerobic and also the aerobic processes. The activated sludge operational swage system with plastic medium as means to aid the microbiologic development, also entices the reception of sludge from WTP into WWTPs, given the fact that some studies have demonstrated this variant type capable of treating a much bigger organic load not even suffering any inhibition over the process. This current study evaluated the reception of a sum up to 400 mg (milligrams) of sludge TSS by sewage liter in a plastic medium as means to aid such process. The sludge from WTP used in here came from systems which utilized Iron and aluminum salt in their processes. Any inhibition regarding the removal of organic or nitrogenated matter in the aerobic process operated with the plastic medium system with the reception of sludge from WTP was observed and/or noticed The BOD5,20 charge which was applied to the biological reactor ranked between 1,7 to 15,3 gDBO5,20/m²/day, and the BOD5,20 average concentration into the final effluent was all the time the experiment was going on in 34 mg/L. Regarding the usage of plastic medium over the nitrification process, removal which jumped from 0,9 gNKT/m²/day to 1,7 gNKT/m²/day, thus an increase of 95%. The evaluation of the sludge generated from the WWTPs primary settling tank demonstrates alteration in its composition, mainly related to VS/TS and the metal concentration augmentation, iron being the most present element in here. Such characteristics may lead to an inhibition regarding the anaerobic process. The specific methanogenic activity (SMA) taking into account the dosages: 0, 4 g and 0, 8 g of TS sludge from WTP shows methanogenesis inhibition for concentrations superior to 0, 4 g of TS. 10% of mass quantity is the amount which no negative effect was noticed when feeding the anaerobic digestor. The SMA test, however, reproduces acute toxicity, not taking into account the possible adaptation that may occur or even demonstrate that the sewage which at first instance could be considered biodegradable is in its real sense chronically toxic. The activated sludge operating with plastic medium has lead the sludge production to reduction of around 57%, before the biofilm maturation the production was 0,19 g VSS/g COD removed and it was upgraded to 0,09 g VSS/g COD removed.

As atividades industriais petroquímicas, incluindo as refinarias de petróleo, são grandes consumidoras de água e, consequentemente, grandes geradoras de efluentes industriais contendo uma infinidade de contaminantes. No caso das refinarias de petróleo brasileiras, o nitrogênio amoniacal tem se tornado um componente crítico a ser tratado, o que tem sido feito através de processos de tratamento biológicos que utilizam a nitrificação como base. Neste trabalho, foi avaliada a operação de um reator de leito móvel (MBBR), em escala de bancada, utilizando suportes de polietileno com área específica de 820 m2.m-3, para tratar um efluente proveniente de uma refinaria brasileira com alta concentração de nitrogênio amoniacal. O efluente bruto apresentou demanda química de oxigênio entre 100 e 300 mg.L-1, teores de nitrogênio amoniacal entre 60 e 90 mg.L-1 e condutividade elétrica entre 1 e 2 mS.cm-1. Mesmo com variações da qualidade da alimentação da planta ao longo do estudo, como o aumento das concentrações de contaminantes, incluindo inibidores da nitrificação típicos dos efluentes de refinaria, a planta atendeu à Resolução CONAMA 430/2011 (BRASIL, 2011), que limita a concentração de descarte em 20 mg.L-1 para o contaminante nitrogênio amoniacal, em 93% das medições. Para o caso de uma fictícia legislação mais restritiva, que exigisse limite de 5 mg.L-1 desse contaminante, houve sucesso no tratamento em 83% do tempo, com eficiência média de nitrificação de 93,1%, evidenciando que há uma possibilidade real de utilização do processo MBBR em refinarias brasileiras.
Petrochemical industrial activities, including oil refineries, are major consumers of water and thus generating large industrial wastewater containing a multitude of contaminants. In the case of Brazilian oil refineries, ammonia nitrogen has become a critical component to be treated, what has been done through biological treatment processes using nitrification as a basis. In this work, the operation of a bench scale moving bed reactor was evaluated (MBBR), using polyethylene biomedia with specific area of 820 m2.m-3, to treat an effluent from a Brazilian petroleum refinery containing high concentrations of ammonia nitrogen, was evaluated. The raw effluent contained between 100 and 300 mg.L-1 of Chemical Oxygen Demand, ammonia nitrogen content between 60 and 90 mg.L-1 and electrical conductivity between 1 and 2 mS.cm-1. Even with the variation of feed quality throughout the study, such as the increasing of concentrations of contaminants, including of typical refinery wastewater nitrification inhibitors compounds, the plant has met the legislation CONAMA 430/2011 (BRASIL, 2011), which limits the discarding concentration of ammonia nitrogen in 20 mg.L-1, in 93% of measurements. In the case of a fictitious more restrictive legislation, requiring a discharge concentration limit of 5 mg.L-1 for this contaminant, the treatment was successful in 83% of the time, with an average efficiency of 93.1% nitrification, showing that there is a real possibility to use the MBBR process in Brazilian refineries.

Muestra la optimización del funcionamiento de la planta de tratamiento de aguas residuales de origen domésticas, propiedad de Aquafil. A lo largo de la investigación se desarrolló la evaluación, análisis y optimización del tratamiento de aguas residuales mediante el adicionamiento de Biocarriers a los dos tanques reactores biológicos existentes, lo cual posibilitará que el sistema de lodos activados actual se transforme en un sistema “Moving Bed Biofilm Reactor” -MBBR- y que fundamentalmente consiste en el aumento de la biomasa en los tanques reactores lo cual permite una mayor degradación de la materia orgánica presente, con el cual se llegar a obtener un incremento del 40% de la capacidad total de tratamiento de la planta que es la meta. Culminado el proceso de optimización actualmente se cuenta con una planta capaz de tratar un caudal promedio de 280 m3/d, lo cual cubre los requerimientos de la población asentada en la ciudad de Caylloma y que comprende un total aproximado de 3200 habitantes.
Tesis

Water and wastewater treatment solutions incorporating biofilm systems are becoming increasingly popular due to more stringent regulations pertaining to drinking water and wastewater effluent discharge in Canada and in other parts of the world. As a major component of biofilm, extracellular polymeric substances (EPS) have been considered as an important factor affecting the physical and chemical properties of biofilm. Further, the selected method of EPS extraction and the methods of detecting the composition of the EPS have shown to affect the results of EPS measurements. In this research, protocols for EPS extraction and EPS composition analysis were investigated and optimized for nitrifying moving bed biofilm reactor (MBBR) biofilm. In addition, the confocal Raman microscopy (CRM) spectra of EPS in nitrifying MBBR biofilm and the protein, polysaccharide and extracellular DNA (eDNA) percent concentrations of the EPS were investigated at various operating temperatures. Further, the CRM spectra and the protein, polysaccharide and eDNA percent concentration of EPS in nitrifying MBBR biofilm along with the biofilm morphology and thickness and the viability of the embedded cells were investigated at various hydraulic retention times (HRTs). The EPS was characterized at various temperatures and HRTs in order to investigate potential correlation between the EPS components of the nitrifying biofilm and the ammonia removal kinetics. The biofilm morphology and thickness along with the bacterial viability of the biofilm were also investigated at various HRTs. Biofilm morphology images and thickness measurements were acquired using a variable pressure scanning electron microscope (VPSEM). The percentages of viable embedded cells in the biofilm were quantified using live/dead staining in combination with confocal laser microscopy (CLSM) imaging. The research demonstrates that an increase in protein content and subsequently a decrease in polysaccharides and eDNA contents in the EPS of nitrifying MBBR biofilm were observed at the lowest operational HRT and the highest temperature in this work. In particular, the EPS protein to polysaccharide (PN/PS) ratio of nitrifying MBBR systems was shown to significantly decrease below a value of 3 when the system was underloaded (observed at the highest operational temperature in this study) or hydraulically overloaded (observed at the lowest HRT in this study). As such, data obtained at lower operational temperatures, with the system no longer underloaded, and at longer HRTs, with the system no longer hydraulically overloaded, all demonstrate an EPS PN/PS ratio of approximately 3. Correlations were observed between the chemically measured EPS PN/PS ratios and the measured Raman spectra intensity ratios; supporting the concept of higher PN/PS ratios of EPS in more optimal nitrifying MBBR operations. Further, the ammonia removal kinetics and EPS response at HRT values of 0.75 and 1.0 h indicate that nitrifying MBBR systems may be optimized to operate at HRTs as low as 0.75 to 1.0 hour as opposed to conventional HRTs of 2.0 to 6.0 h.

CAPES
As indústrias de celulose são caracterizadas pelo alto consumo de água em seus processos produtivos, gerando consequentemente grandes volumes de efluentes líquidos que apresentam na maior parte de sua composição compostos lignínicos, matéria orgânica, cor e toxicidade. O efluente de celulose, quando não tratado ou tratado de forma indevida, pode comprometer a qualidade da água dos corpos receptores, por conter substâncias tóxicas à comunidade aquática. O objetivo do trabalho foi avaliar a eficiência de tratamento de efluente de celulose e papel por reator MBBR, através da remoção de matéria orgânica (DQO e DBO5), compostos fenólicos, cor, compostos lignínicos e aromáticos. Para isso um reator MBBR em escala de bancada foi operado por 180 dias com diferentes velocidades de carga orgânica 0,2; 0,4; 1,2; 4,0; 9,0 kgDQO/L.d. Neste foi quantificada também a biomassa aderida e em suspensão na massa liquida. O efluente analisado apresentou 48 e 94% de remoção de DQO e DBO5 respectivamente, também houve remoção de compostos fenólicos e cor de 24 e 12% para VCO de 0,4 kgDQO/L.d, para mesma VCO a remoção de compostos lignínicos e aromáticos foi de 16 e 8,5 % respectivamente.
The pulp mills are characterized by high water consumption their production processes, thereby generating large volumes of effluents that present in most of composition lignínicos compounds, organic matter, color and toxicity. The wastewater from pulp, if left untreated or treated improperly, can compromise the water quality of receiving waters, which contain substances toxic to the aquatic community. The objective of this study was to evaluate the efficiency of wastewater treatment of pulp and paper by MBBR reactor, through the removal of organic matter (COD and BOD5), phenolic compounds, color, and aromatic compounds lignínicos. To this reactor MBBR bench scale was operated for 180 days with different speeds organic load 0.2, 0.4, 1.2, 4.0, 9.0 kgCOD / Ld This was also quantified and attached biomass in suspension in the liquid mass. The wastewater analysis showed 48 and 94% removal of COD and BOD5 respectively, were also removing phenolic compounds and color of 24 and 12% for 0.4 kgDQO VCO / Ld VCO same for removal of aromatic compounds and was lignínicos 16 and 8.5% respectively.

I examensarbetet har möjlig denitrifikationshastighet för lakvattnet på Bredemads avfallsdeponi i Ljungby undersökts. Denitrifikationshastigheten har tagits fram i satsvisa och kontinuerliga försök där Reppos 40T och Brenntaplus VP1 har jämförts som externa kolkällor. De satsvisa försöken har genomförts i temperaturerna 15 °C, 20 °C och 22,5 °C och de kontinuerliga försöken har genomförts med reningsmetoden ”Moving Bed Biofilm Reactor” (MBBR) med bärare som hade en skyddad yta på 500 m2/m3. Denitrifikationshastigheten i g/(dygn•m2) med Reppos 40T var 0,45 och med Brenntaplus VP1 1,05. I reaktorn med Reppos 40T var fyllnadsgraden 48 % och denitrifikationshastigheten 4,5 g/(h•m3). I reaktorn med Brenntaplus VP1 var fyllnadsgraden 41 % och denitrifikationshastigheten 9,1 g/(h•m3).

As the microbrewery industry expands, disposal of brewery wastewater is becoming more of a concern, both for brewery operators and for local municipal wastewater authorities. Brewery wastewater is characterized as containing high strength organics and high variability in both organic and hydraulic loading. This high variability increased the challenge of treating brewery wastewater properly. Therefore, it is significant for optimizing the operation condition for the small-scale wastewater treatment system. This study conducted a batch study and a field study for optimizing a craft brewery on-site wastewater treatment system, which is equipped with two moving bed biofilm reactors (MBBR). In the batch study, a two-factor Box-Wilson central composite design (CCD) was adopted to find optimum biomethane production conditions for the digestion of brewery wastewater with a dairy manure inoculum. The effects of two major influencing factors of temperature (T) (25-49°C) and brewery wastewater concentration (BWC) (2-9 g VS/L) on biochemical methane potential (BMP) (CH₄ yield) and CH₄ maximum production rate (Rmax) were evaluated by applying response surface methodology (RSM). All of the trials presented a high organic removal efficiency with volatile solid (VS) 82-91%, soluble chemical oxygen demand (sCOD) 77-88%, and total chemical oxygen demand (tCOD) between 47% -76%. The experiment result suggested that the first-order kinetic rate constant and biogas content (methane percentage in the biogas) can be affected by the temperature. The mesophilic regime had the highest average rate constant, and the psychrophilic regime rate constant was significantly lower than the mesophilic and thermophile regime. The conditions in the thermophile range present a high variability for the first-order rate constant. The methane ratio in the biogas increased and stabilized by the operation time. Mesophilic and thermophilic regimes obtained a stabile biogas content around 25 days, and the psychrophilic regime spent extra time to stabilized. At the end of the anaerobic digestion, the psychrophilic, mesophilic, and thermophilic regimes had an average methane percentage of 47%,65%, and 67% respectively. Optimum BMP and Rmax were achieved under conditions of 49 °C and BWC of 5g VS/L. Correspondingly, the BMP and Rmax were 141.40 mL CH₄/g VS added and 36.5 mL CH₄/ day, respectively. However, by pursuing stability the preferable operational condition T=35℃ and BWC=5 g/L is recommended, at this condition methane yield is 110.07 CH₄/g VS added and maximum methane daily production is 28.06 CH₄/ day, which is similar to the maximum result. In field study, an on-site brewery wastewater treatment system equipped with two MBBR reactors was evaluated from October 12th, 2018 to February 10th, 2020 in Beau`s All-Natural Brewing Company, Vankleek Hill, Ontario, Canada. The aim of the study was to characterize the wastewater production (flow and organic loading rate), evaluate the operating conditions and performance of the MBBR system, and recommend improvements. Discharge from the brewery is highly variable for both organic and hydraulic loading with flow balancing recommended. The MBBR full-scale reactors operated at relatively stable conditions at a surface area loading rate (SALR) of less than 25 g/m2.d and dissolved oxygen (DO) greater than 2mg/L. Kinetic rate constants for suspended growth and attached growth biomass in the reactors were found to be similar at 0.0764-0.0908 h-1, however, a much larger attached growth mass in the reactors suggests that only a fraction of the attached growth biofilm is active. Effluent recycle was shown to be effective at controlling filamentous bacteria (type-0041) sludge bulking, reducing suspended solid concentration, and sCOD concentration.

Papermaking process require large amounts of energy and water; therefore, pulp and paper mills can be potentially very polluting. The wastewater resulting from the papermaking process must be carefully managed as it is very rich in dissolved organic matter and contain compounds that make it difficult to treat. MBBR technology emerged as a possibility to increase the treatment capacity and to make more compact treatment systems designed to remove high organic loads, since in addition to having biomass in suspension as the activated sludge process, also has biomass adhered to plastic supports. This research was commissioned by Stora Enso Kvarnsveden and emerged in need of a bioreactor modification due to reduction of the wastewater load after the closure of PM11 in 2013 and PM8 in 2017. An evaluation of the performance of bioreactors is necessary with possible results to only run one bioreactor in the future and save energy. For performance analysis, two weeks of measurements were performed, one with the two bioreactors running at the same time and one with only K150 reactor running, trying to simulate what happens if one of them is stopped. Analysis of the main operating parameters of the MBBR system were evaluated during this research. As result, it was recommended an action to remove the excess of adhered biomass and an increase of the filling rating to 50%, in order to optimize TOC reduction.

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico, Programa de Pós-Graduação em Engenharia Química, Florianópolis, 2013.
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A tendência é que nos grandes centros urbanos as estações de tratamento de efluentes apresentem arquitetura que privilegie plantas compactas, com operação estável, baixo impacto ambiental e visual, além de redução nos níveis de odores e ruídos. Neste cenário, as ETEs que empregam a tecnologia MBBR (reatores de leito móvel com biofilme) surgem como uma excelente alternativa, pois apresentam instalações compactas, com impactos relativamente baixos, além de serem altamente resistentes aos choques de carga orgânica, de temperatura e de toxicidade. Este processo utiliza elementos suportes para fixação do biofilme, mantidos em suspensão no reator através de sistemas de aeração ou agitadores mecânicos, empregando microrganismos em suspensão e aderidos aos meios suportes, aumentando a quantidade de biomassa contida no reator. Este trabalho investiga o desempenho de um MBBR quanto à remoção de carga orgânica e nitrificação, submetido a quatro diferentes condições experimentais, de acordo com o planejamento fatorial elaborado 22. Tendo como objetivo principal buscar a condição experimental que resulte em um melhor funcionamento do processo MBBR foram variadas a velocidade superficial do ar (UG) e o tempo de retenção hidráulica (TRH). O meio suporte utilizado, contendo 490 m2.m-3 de área superficial específica interna, foi introduzido no reator biológico de acordo com uma razão VS/VR (razão entre o volume de meio suporte e o volume do reator) de 25%. Após o reator biológico, alimentado com efluente sanitário, foi instalado um decantador para separação do efluente tratado do lodo excedente. O MBBR foi operado por um período total de 120 dias, sendo que cada condição experimental operou por 30 dias. As velocidades superficiais do ar empregadas foram de 1,78 e 3,57 m.h-1 e os tempos de retenção hidráulica de 8,33 e 12,00 h. A concentração de sólidos suspensos totais no meio reacional foi em média de 218 mg.L-1, característicos de sistemas MBBR. O biofilme apresentou boa atividade, medida através da taxa de consumo de oxigênio. As microscopias realizadas no período de testes mostraram o desenvolvimento de um biofilme fino e denso, recobrindo somente a superfície interna do meio suporte. Foi observada também à predominância de rotíferos, indicativos de alto tempo de retenção celular. As eficiências globais de remoção de DQO e o percentual de nitrificação, considerando os resultados obtidos nas quatro condições experimentais, foram de 73 e 89%, respectivamente. Sendo que a condição 3 (TRH = 8,33 h e UG = 3,57 m.h-1) apresentou os melhores resultados de eficiência. A análise dos efeitos das variáveis independentes (UG e TRH) sobre as variáveis de resposta (?DQO e ?N-NH4+) revelaram que para a eficiência de remoção de DQO, o tempo de retenção hidráulica foi o parâmetro que apresentou maior influência, enquanto que a eficiência de nitrificação foi mais afetada pela velocidade superficial do ar. As superfícies de resposta obtidas evidenciaram que para uma remoção de DQO e nitrogênio amoniacal de 76% e 90%, respectivamente, deve ser empregado TRH de 12,00 h e UG de 3,80 m.h-1. Com base nestes resultados, o investimento para implantação de uma planta MBBR é apenas 15% maior do que o investimento para um sistema de lodos ativados, possibilitando o uso desta tecnologia mesmo para ETEs de pequeno porte.

Abstract : Tendency in the urban centers is that the wastewater treatment plants present an architecture that favors compact plants, with stable operation, low visual and environmental impact, beyond the noise and odors levels reduction. On this scenery, WTP´s based on MBBR technology (Moving Bed Biofilm Reactor) come up with an excellent choice, because they have compact set installation, relatively low impact, besides being highly resistant to the shocks of organic load, temperature and toxicity. That process makes use of carrier for the biofilm growth, held in suspension in the reactor through the aeration or mechanic stirring system, by using microorganism in suspension and adhered to carrier, increasing amount of biomass in the reactor. This job investigates the performance of a MBBR concerning the organic load removal and nitrification, under four different operating systems, according to the undertaken factorial design 22. As prior aim, looking forward to an operational condition that comes to better MBBR working process, there were different levels on the air superficial velocity (UG) and hydraulic retention time (HTR).The used carrier, with 490 m2. m-³ specific surface area inner, was put in the biological reactor according to VS/VR (carrier filling ratio) of 25%. After the biological reactor, fed up with sewage, it was installed a clarifier to set apart treated effluent and excess sludge. MBBR was operated for a period of 120 days, being each experimental condition operated for 30 days. Air superficial velocity applied ranked from 1.78 and 3.57 m.h-1 and hydraulic retention time, from 8.33 and 12.00 h. Overall concentration of total suspended solids in the reaction mean was in the average of 218 mg.L-1, characterizing MBBR system. Biofilm showed good activity, measured through oxygen uptake rates. Microscopy performed in that testing period showed the development of the thin and thick biofilm, covering only the inner surface of the carriers. It was also noticed the rotifers prevalence, pointing out cells retention long time. Overall efficiency of COD removal and nitrification percentage, considering given results in the four operation systems, were between 73 and 89% respectively. Therefore, the condition 3 (TRH = 8,33 h e UG = 3,57 m.h-1) showed the best efficiency results. Analysis of the independent variable effects (UG and HRT) over the answering variables (?COO e ?N-NH4+) revealed that for the efficiency of COD removal ,hydraulic retention time was the parameter setting that showed more influence, while nitrification efficiency was more influenced by the air superficial velocity. Obtained response surfaces revealed that COD and ammonium nitrogen removal of 76% and 90%, respectively, it must be applied HRT of 12.00 h and UG of 3.80 m.h-1. Based on these results, investment for the deployment of a MBBR is only 15% higher than the investment for the activated sludge, making possible the usage of this technology even for smaller WTP's.

The study is about Nitrogen removal from the low concentrated mainstream wastewater after Upflow Anaerobic Sludge Blanket reactor process (UASB) by single-stage Partial Nitritation/Anammox process in a pilot scale reactor at Hammarby Sjöstad in Stockholm. A mixture of various concentrations of dissolved oxygen and different aeration methods have been tested in the pilot scale reactor in five months divided into five periods where the temperature was set at 15° C throughout the study. The best result was in period 4, the average nitrogen removal efficiency was 52% varying between 40 and 60 % with aeration method of the ratio R = 1/3 (R = 20 minutes with aeration to 40 minutes without aeration) and a dissolved oxygen concentration of 1.3 mg/L. Partial nitritation/Anammox is considered more environmentally friendly due to reduced energy requirements for aeration, no need for an external carbon source. The process also allows for a more cost-effective nitrogen removal from wastewater.
Vatten är nödvändigt för existensen av allt liv på jorden och spelar en avgörande roll i alla mänskliga aktiviteter. Antropogena aktiviteter förorenar denna viktiga resurs och medför stor risk för människors och djurs hälsa samt växter. Kvävebelastning från jordbruket och avloppsvatten i mark- eller vattenmiljön har resulterat till övergödning, vilket är ett miljö- och ekonomiskt problem på grund av en obalans mellan ekosystemtillförseln och den naturliga näringsförbrukningen. I denna studie behandlades avloppsvatten i en pilotskala reaktor med en integrerad fastfilm aktiverat slam (IFAS) som drivs med ett enstegs partial nitritation/Anammox-process. Kväverening från den lågkoncentrerade huvudström avloppsvatten efter Uppflöde Anaerob Slam Blankett reaktor process (UASB) undersöktes. En blandning av olika koncentrationer av upplöst syre och olika luftningsmetoder har testats i pilotskala reaktorn i fem månader uppdelad i fem perioder där temperaturen sattes vid 15° C under hela studien. De bästa resultaten i kväve reningseffektivitet var 52 % i genomsnitt i period 4 varierande mellan 40 och 60 %, luftningsmetod med ett förhållande av R = 1/3 (R = 20 minuter med luftning till 40 minuter utan luftning) och ett upplöst syre Koncentration av 1,3 mg/l. Jämförelsen tog hänsyn till alla former av utsläpp av kväve- och energikostnader för luftning. Under de senaste decennierna har vattenbehandlingsprocesserna haft många positiva utvecklingar, vilket har lett till en kvalitetsförbättring av vatten samtidigt som kostnaden för kväveavlägsnande från avloppsvatten har minskat. För närvarande flyttar kvävereningsteknik från konventionell nitrifikations/denitrifikationsprocessen till partiell nitritation/Anammox (PN/A) -processen kallad deammonification. Det verkar som om den största svårigheten är att upprätthålla en stabil ackumulation av nitrit medan man försöker delvis med nitritation av ammonium. Partiell nitritation/Anammox (PN/A) anses vara mer kostnadseffektivt avlägsnande av kväve från avloppsvatten, mer miljövänligt än konventionella nitrifikations-denitrifikationsprocesser på grund av minskat energibehov för luftning och inget behov av en yttre källa av kol.

Il presente elaborato si pone l'obiettivo di confrontare ed analizzare due configurazioni diverse di un depuratore di acque reflue appartente ad un'azienda che produce alimenti. Le configuarazioni in questione sono: fanghi attivi e MBBR (Moving Bed Biofilm Reactor). L'analisi è stata effettuata mediante un modello di qualità delle acque, in particolare Qual2k, software gratuito promosso dall' Environmental Protection Agency (EPA). Infatti, è stato valutato il comportamento del corpo idrico in cui sversa lo scarico dell'azienda, prima nel caso di trattamento a fanghi attivi, poi nel caso di trattamento con MBBR. Si tratta di un canale di bonifica appartenente al Consorzio di Bonifica della Romagna Occidentale, in particolare si tratta dello Scolo Diversivo in Valle. E' un canale di piccole dimensioni, infatti, dall'analisi è risultato che le reazioni di degradazione degli inquinanti che solitamente avvengono spontaneamente all'interno di un corpo idrico superficiale, in questo caso fanno fatica ad avvenire. Di fatti il volume di reazione non è sufficiente affinchè il corso d'acqua riesca ad autodepurarsi ed è quindi importante fare attenzioni alle concentrazioni degli scarichi che avvengono all'interno e cercare di adottare tecnologie sempre migliori per ovviare al problema.

Effective treatment of wastewater is an important process in reducing the environmental impact of industry and human activity. Although conventional water treatment systems can adequately remove the principle components of waste (i.e. substances that can be represented the majority of biological and chemical oxygen demand) several materials are poorly or slowly removed. Tertiary treatment polishing processes are therefore required to remove these contaminants to ensure complete wastewater treatment. This thesis reports investigations made using film reactors that are used to remove recalcitrant materials such as ammonia- nitrogen and endocrine disrupters that although present in low concentrations, if left untreated can have a strong impact on the environment. Film reactors potentially offer several process advantages over conventional activated sludge treatments systems as they allow very long residence time and contact with high concentrations of fixed microbes with the low concentrations of pollutants so enhancing kinetic performance and efficiency of the process. Two reactor configurations, a partial fixed bed (PFBR) and moving bed biofilm reactors (MBBR) were investigated. A thirty liter reactor with a working volume of 16 liters was constructed and contained fixed microbial films on either free suspended or fixed beds plastic packing (K2 AnoxKaldnes). The investigation of ammonia-nitrogen oxidation showed that after a suitable acclimation period (2 weeks) that ammonia was oxidise rapidly reducing the feed concentrations of 35 mg/L to < 2 mg/L in the effluent. To assess the performance for ammonia-nitrogen removal the reactors operated for long periods (up to 3 months) with continuous feed using the reactor in either PFBR or MBBR modes in addition of 17alpha-ethynylestradiol (EE2) and mestranol (MeEE2), the endocrine disrupting compounds commonly found in municipal wastewater. These substances is derived from a synthetic hormones if found in the natural environment can reduced the productivity of the fish as this can cause feminization in aquatic organisms with disastrous consequences on fish populations. The MBBR and PFBR systems were used to investigate the co-metabolism of ammonia-nitrogen, 17alpha-ethynylestradiol (EE2) and mestranol from model waste water feed containing 35 mg/L of ammonia-nitrogen and 100 mug/L of 17alpha-ethynylestradiol (EE2) and mestranol (MeEE2). A kinetic analysis of the systems were made and for the PFBR reactor, the specific growth rate, mumax of 7.092 d-1 with saturation constants, Ks of 1.574 mg/L. The kinetic analysis for the MBBR system was 6.329 d-1 for the mumax with the K.S of 0.652 mg/L. When the PFBR was used removal of EE2 represents 70% MeEE2 was removed. MBBR were shown to be more effective and efficient in removing ammonia-nitrogen reducing the levels under good conditions to > 2 mg/L while the PFBR could also achieve 2 mg/L. The MBBR system was also more competent in the removal of 17alpha-ethynylestradiol (EE2) and mestranol compared to PFBR. This work demonstrates that there are considerable advantages to using thin film reactors as polishing step for the tertiary treatment of waste waters when to compared to other processes in reducing the inorganic pollutants as endocrine disrupting compounds. The significance of these results is discussed in this context.

By rethinking wastewater treatment plants (WWTPs) as resource recovery facilities, it is possible to de- velop the next generation of WWTPs. Moreover, it allows to accomplish environmental goals, such as reducing the CO2 footprint, and comply with increasing effluent standards regarding the concentration of nitrogen in a more sustainable way. This research study aims to analyse the possibility of recirculating carbon within WWTPs in form of volatile fatty acids (VFAs) produced by co-fermentation of primary sludge and food waste. The obtained fermentation liquid is utilised as carbon source to enhance the denitrification process in a post-anoxic denitrification plant setup. Two pilot scale fermentation reactors were semi-continuously operated, systematically varying only in pH. By controlling one reactor to pH 10, while the second reactor was operated without pH control, it was possible to assess the influence of the pH on the carbon recovery process. Despite the pH not being controlled in the second fermentation reactor, it adjusted itself to a stable pH around 5.4. The co-fer- mentation process was monitored by weekly analysis of the SCOD and total amount of VFAs (TVFA). While the alkaline conditions in the reactor operated at pH 10 allowed a higher hydrolysis of the sub- strate, the second reactor, operated without pH control, achieved a more distinct acidification, due to the lower pH. Consequently, the SCOD in the reactor operated without pH control contains a higher percentage of TVFA amounting to 64 % in comparison to the reactor operated at pH 10 with 40 % TVFA. Furthermore, the achieved degree of fermentation was assessed by calculating the net increase of TVFA per gram of VS, respectively VSS. A higher degree of fermentation was achieved without pH control, resulting in a higher VFA yield compared to the fermentation reactor operated at pH 10. Moreover, anal- ysis of the individual VFAs by gas chromatography showed distinct differences in the composition of the fermentation liquids. According to the findings, the reactor operated at pH 10 produced mainly acetic acid (61 %), followed by propionic acid (18 %) and n-butyric acid (14 %). In contrast, the fermentation reactor operated without pH control produced mainly n-caproic acid (47 %), followed by acetic acid (25 %) and n-butyric acid (16 %). Despite the similar fermentation substrate supplied to both reactors, the acidic conditions in the reactor operated without pH control allowed carboxylic acid chain elongation from acetic acid to n-caproic acid, resulting in the main difference of the fermentation liquids. The fermentation liquid of the two reactors was filtered, diluted to a concentration of 5 g COD/L and supplied as additional carbon source to enhance denitrification in two continuously operated pilot scale moving bed biofilm reactors (MBBR), applying a carbon-to-nitrogen ratio of 4.5. One of the denitrifica- tion MBBRs received the carbon recovered by fermentation at pH 10 as external carbon source, whereby the carbon source produced by fermentation without pH control was supplied to the other MBBR. The maximal achieved denitrification rate was quite similar for both MBBRs amounting to 3.25 g NO3- Neq/(m2·d) for the MBBR receiving the carbon source recovered by co-fermentation at pH 10 and 3.38 g NO3-Neq/(m2·d) for the MBBR receiving the VFA-mix obtained by co-fermentation without pH control. However, the MBBR provided with the carbon source recovered by co-fermentation under acidic conditions achieved a higher average denitrification rate of 2.5 g NO3-Neq/(m2·d), compared with the MBBR receiving carbon produced by co-fermentation at pH 10 (1.8 g NO3-Neq/(m2·d)). The lower efficiency of the MBBR supplied with additional carbon recovered by fermentation at pH 10 is caused by an accumulation of NO2-N during the denitrification process. This accumulation of NO2-N indicates suboptimal conditions, both due to the composition of the supplied carbon source and an overall higher pH during the denitrification process, which might supress facultative anaerobes, such as denitrifiers. Nevertheless, this study shows that both VFA-rich carbon sources obtained by co-fermentation of pri- mary sludge and food waste are suitable to enhance denitrification of municipal wastewater, with the carbon source recovered by fermentation without pH control achieving a higher denitrification effi- ciency.
Eine Neuinterpretation kommunaler Klärwerke als Rohstoff-Rückgewinnungsanlagen ermöglicht die Entwicklung der Kläranlagen der Zukunft. Umweltziele, wie die Reduktion des CO2-Fußabdrucks und die Einhaltung steigender Abwasserstandards im Hinblick auf die Stickstoffkonzentration können somit nachhaltiger erreicht werden. Diese Forschungsstudie zielt darauf ab, die Möglichkeit der Rückführung von Kohlenstoff in Kläranlagen in Form leichtflüchtiger Fettsäuren (engl. volatile fatty acids, VFAs) zu untersuchen. Diese VFAs werden durch Co-Fermentation von Primärschlamm und Lebensmittelabfäl- len erzeugt und als zusätzliche Kohlenstoffquelle einer nachgeschalteten Denitrifikation zugeführt, um die Prozesseffizienz zu steigern. Zur Erzeugung der VFAs wurden zwei Fermentationsreaktoren halbkontinuierlich im Pilotmaßstab be- trieben, welche systematisch im pH-Wert variierten. Der Einfluss des pH-Wertes auf den Kohlenstoff- rückgewinnungsprozess konnte beurteilt werden, indem ein Reaktor auf pH 10 geregelt wurde, während dieser im zweiten Reaktor nicht beeinflusst wurde. In diesem stellte sich aufgrund ablaufender Reakti- onen ein stabiler pH-Wert um 5,4 ein. Der Co-Fermentationsprozess wurde durch wöchentliche Analyse des gelösten chemischen Sauerstoffbedarfs (engl. soluble chemical oxygen demand, SCOD) und der Ge- samtmenge an VFAs (TVFA) überwacht. Während die alkalischen Bedingungen in dem bei pH 10 be- triebenen Reaktor eine höhere Hydrolyse des Substrats ermöglichten, erreichte der zweite Reaktor auf- grund des niedrigeren pH-Werts eine stärkere Versäuerung. Folglich enthält der SCOD in dem Reaktor, der ohne pH-Regelung betrieben wurde, mit 64 % einen höheren Anteil an TVFA im Vergleich zu dem bei pH 10 betriebenen Reaktor mit 40 % TVFA. Außerdem wurde der erreichte Fermentationsgrad durch Berechnung der Nettozunahme der TVFA pro Gramm flüchtige Feststoffe (VS) bzw. flüchtige suspendierte Feststoffe (VSS) erfasst. Ein höherer Fer- mentationsgrad konnte ohne pH-Regelung erzielt werden, welche eine höhere VFA-Ausbeute im Ver- gleich zur Fermentation bei pH 10 zeigt. Deutliche Unterschiede in der Zusammensetzung der gewon- nenen VFAs konnten durch Analyse mittels Gaschromatographie erfasst werden. Demzufolge entstand bei der Fermentation bei pH 10 hauptsächlich Essigsäure (61 %), gefolgt von Propionsäure (18 %) und n-Buttersäure (14 %). Im Gegensatz dazu, produzierte der Fermentationsreaktor ohne pH-Regelung überwiegend n-Capronsäure (47 %), gefolgt von Essigsäure (25 %) und n-Buttersäure (16 %). Trotz des gleichen Fermentationssubstrates, welches beiden Reaktoren zugeführt wurde, ermöglichen die sauren Bedingungen in dem Fermentationsreaktor ohne pH-Regelung, eine Verlängerung der Carbonsäureket- ten von Essigsäure zu n-Capronsäure. Nach Filtration der in verschiedenen Milieus gewonnenen Fermentationssubstrate und Verdünnung auf eine Konzentration von 5 g COD/L, wurden diese zwei im Pilotmaßstab kontinuierlich betriebenen Fließbett-Biofilmreaktoren (engl. Moving bed biofilm reactor, MBBR) als zusätzliche Kohlenstoffquelle zur Denitrifikation zugeführt. Über die gesamte Versuchsdauer wurden ein MBBR mit dem alkalisch gewonnenen und der Andere mit dem im sauren Milieu erzeugten VFA-Mix betrieben. Das Kohlenstoff- Stickstoff-Verhältnis (C/N Ratio) lag dabei bei 4,5. Beide MBBRs wiesen eine vergleichbare maximale Denitrifikationsrate von 3,25 g NO3-Neq/(m2·d) (VFAs pH 10) und 3,38 g NO3-Neq/(m2·d) (VFAs pH un- geregelt) auf. Der MBBR, welcher die im sauren Milieu rückgewonnene Kohlenstoffquelle erhielt, er- reichte im Durchschnitt eine höhere Denitrifikationsrate von 2,5 g NO3-Neq/(m2·d) als der MBBR, der den bei pH 10 gewonnenen VFA-Mix erhielt (1,8 g NO3-Neq/(m2·d)). Die im Vergleich geringere Effizi- enz der alkalisch rückgewonnenen Kohlenstoffquelle wird durch eine NO2-N-Anreicherung während der Denitrifikation verursacht, welche suboptimale Bedingungen während des Prozesses indiziert. Dies ist sowohl auf die Zusammensetzung der zugeführten Kohlenstoffquelle, als auch auf einen insgesamt hö- heren pH-Wert während des Reduktionsprozesses zurückzuführen, der fakultative Anaerobier, wie bspw. Denitrifikanten, unterdrücken kann. Dessen ungeachtet zeigt diese Studie, dass beide durch Co- Fermentation von Primärschlamm und Lebensmittelabfällen gewonnenen VFA-reichen Kohlenstoff- quellen zur Verbesserung der Denitrifikation kommunalen Abwassers geeignet sind, wobei die durch Fermentation ohne pH-Regelung erzeugte Kohlenstoffquelle eine höhere Effizienz aufweist.
Det är möjligt att utveckla den nya generationen av avloppsreningsverk genom att ompröva avloppsreningsverk som resursanläggning. Därtill möjliggör det att uppnå miljömål som att minska koldioxidavtrycket och följa ökande utsläppskrav, t.ex. för kvävekoncentration, på ett mer hållbart sätt. Denna forskningsstudie syftar till att analysera möjligheten att återcirkulera kol inom reningsverket i form av lättflyktiga fettsyror (engl. volatile fatty acids, VFAs), producerades genom samfermentering av primärslam och matavfall. Det erhållna fermenteringssubstratet används som extern kolkälla för att förbättra processeffektiviteten i en efterdenitrifikationsanläggning. Två pilotskaliga fermenteringsreaktorer drevs i semikontinuerligt driftläge med endast en skillnad i pH. Det var möjligt att utvärdera pH-påverkan på kolåtervinningsprocessen genom att kontrollera pH- värdet i en reaktor till pH 10, medan den andra reaktorn drevs utan pH-kontroll. På grund av reaktionerna som fortlöpte, justerade sig den icke-kontrollerade reaktorn själv till ett stabilt pH runt 5,4. Samfermenteringsprocessen övervakades genom veckoanalys av kemisk syreförbrukning i filtrerade prover (engl. soluble chemical oxygen demand, SCOD) och total mängd av VFAs (TVFA). Medan den alkaliska miljö i den första reaktorn gynnade en högre hydrolys av substratet, uppnådde den andra reaktorn en mer tydlig surgöring på grund av det lägre pH-värdet. Följaktligen innehåller SCOD i reaktorn som drivs utan pH-kontroll en större andel TVFA – 64 % av SCOD - jämfört med reaktorn som drivs vid pH 10, där TVFA utgör 40 % av SCOD. Vidare analyserades den uppnådda fermenteringsgraden genom att beräkna nettoökningen av TVFA per gram VS, respektive VSS. En högre jäsningsgrad uppnåddes i sur miljö, vilket resulterade i en högre VFA-produktion jämfört med fermenteringsreaktorn som drevs vid pH 10. Därtill visade analys med gaskromtografi av de individuella VFA tydliga skillnader i sammansättning av substraten. Enligt rönen producerade reaktorn vid pH 10 mestadels ättiksyra (61 %) följt av propionsyra (18 %) och n-smörsyra (14 %). Däremot producerade fermenteringsreaktorn utan pH-kontroll mestadels n-kapronsyra (47 %) följt av ättiksyra (25 %) och n-smörsyra (16 %). Detta visar att trots att samma fermentationssubstrat användes för båda reaktorerna möjliggör den sura miljön i reaktorn utan pH-kontroll karboxylkedjeförlängningen från ättiksyra till n-kapronsyra. Fermentationssubstraten av de två reaktorerna filtrerades, utspäddes till en koncentration av 5 g COD/L och tillfördes som extern kolkälla, med ett kol/kväve-förhållande på 4,5, för att förbättra denitrifikationen i två kontinuerliga drivna biofilmreaktorer med rörliga bärare (engl. moving bed biofilm reactor, MBBR). En MBBR erhöll under hela experimentets gång den kolkälla som bildats under alkaliska förhållanden och den andra MBBR:en erhöll motsvarande kolkälla som bildats i den sura miljön i fermenteringsreaktorn utan pH-kontroll. Den maximala uppnådda denitrifikationskapaciteten var ganska likartad för båda MBBR: 3,25 g NO3-Neq/(m2·d) för den MBBR som opererades med den alkaliska erhållen kolkällan och 3,38 g NO3-Neq/(m2·d) för MBBR som erhöll den utspädda fermenteringsvätskan bildad utan pH-kontroll. Emellertid uppnådde den MBBR som erhöll kolkällan bildad i sura miljön en högre genomsnittlig denitrifikationskapacitet på 2.5 g NO3-Neq/(m2·d) jämfört med MBBR som fick kolkällan producerad genom fermentering vid pH 10 (1.8 g NO3-Neq/(m2·d)). Den lägre effektiviteten i den MBBR som fick den alkaliskt erhållna kolkällan orsakas av en ansamling av NO2-N under denitrifikationsprocessen, vilket indikerar suboptimala förhållanden. Detta beror både på sammansättningen av den tillförda kolkällan och ett högre totalt pH-värde under reduktionsprocessen, vilket kan hämma fakultativa anaerober såsom denitrifierare. Trots det visar denna forskningsstudie att båda de VFA-rika kolkällorna erhållna genom samfermentering av primärslam och matavfall är lämpliga för att förbättra denitrifikationen av kommunalt avloppsvatten, varvid kolkällan som produceras genom fermentering utan pH-kontroll uppnår en högre denitrifikationseffektivitet.

Mestrado em Engenharia do Ambiente
A diminuição dos recursos fósseis bem como a abundância de biomassa renovável e que pode ser valorizada tem levado a encarar com boas perspectivas o processo de biorefinaria, sendo actualmente uma área em grande desenvolvimento. No sector dos plásticos os PHAs tem-se revelado uma alternativa sustentável em relação aos plásticos convencionais. O principal substrato para produzirem estes biopolímeros são os AOVs, produtos resultantes da fermentação acidogénica de resíduos orgânicos, como por exemplo o soro de queijo. Os AOV são compostos de alto valor económico devido às suas diversas aplicações. Neste trabalho foi estudado o processo de acidificação anaeróbio de soro de queijo, com a imposição na alimentação de valores de alcalinidade de 2000 e 5000 mg CaCO3/L e cargas orgânicas de 20 e 50 gCQO/L.d. Foram avaliadas as condições que produziam maior quantidade de ácidos e quais os tipos de ácidos mais produzidos em cada condição, num reactor MBBR. Foi também comparado a produção de AOV num reactor CSTR para a condição de 2000 mgCaCO3/L e 20 gCQO/L.d. Comparando as condições de 20 g CQO/Ld. e alcalinidade 2000 mg CaCO3/L e 5000 mg CaCO3/L é possível verificar que a produção de ácidos foi de 43301 mgCQO/L ± 618,3 e 5184,4 mgCQO/L ± 640,5, respectivamente, e o grau de acidificação foi de 41,6% ± 5,9 e 50,8%, respectivamente. Para a carga de 50 gCQO/L.d. e 2000 mgCaCO3/L verifica-se uma produção de ácidos de 10335,7 mgCQO/L ± 1077,6 e um grau de acidificação de 41,3%. Enquanto que para a mesma carga orgânica e alcalinidade 5000 mgCaCO3/L obteve-se 8693,6 mgCQO/L ± 1960,2 e um grau de acidificação de 30,1%. O ácido n-butírico é o mais produzido nas quatro condições. No reactor CSTR obteve-se uma média de 3555,69 mgCQO/L ± 706,89 e um grau de acidificação de 34,9%, valores estes menores do que os obtidos no MBBR nas mesmas condições. Todos os tipos ácidos são produzidos em maiores quantidades no MBBR, excepto o ácido i-valérico e n-caproico.
The decrease of fossil resources and the abundance of renewable biomass can be valued has led to face with good prospects biorefinery process , currently being an area in great development . In the plastics sector PHAs has proved to be a sustainable alternative to conventional plastics. The main substrate to produce these biopolymers are AOVs , products resulting from acidogenic fermentation of organic wastes such as cheese whey . AOVs have high economic value due to its various applications . In this work was studied,for various conditions of alkalinity , 2000 and 5000 mgCaCO3 / L and organic loading rate of 20 and 50 gCOD / L.d. that produced the largest amount of AOVs and wich kind of acids were produced in each condition , on a MBBR reactor . It was also compared the production of acids in a CSTR for the condition of 2000 mgCaCO3 /L and 20 gCOD / L.d. Comparing the conditions of 20 gCOD / L.day to 2000 mg CaCO3 / L and 5000 mg CaCO3 / L is possible to verify that the production of AOV were 43301 mgCQO/L ± 618,3 and 5184,4 mgCQO/L ± 640,5, respectively, and the degree of acidification was 41,6% ± 5,9 and 50,8% ± 3,9,respectively. For organic loading rate of 50 g COD / L.d. and 2000 mg CaCO3 / L there is a production of acids of 10335.7 mg COD / L ± 1077.6 and a degree of acidification of 41,32 %. While in the same organic loading and alkalinity of 5000 mg CaCO3 / L was obtained 8696,6 mg COD / L ± 1960,2 of AOVs and a degree of acidification of 30,1 %. N-butyric acid is the most produced AOV on all MBBR conditions. In the CSTR was obtained an average of 3555.69 COD mg / l ± 706.89 of AOVs and a degree of acidification of 34.92 %, which are lower than those obtained in the MBBR the same conditions. All kind of AOV are produced in a larger quantities on MBBR except i-valeric and n-caproic.

There is an urgent need to develop ammonia removal treatment systems for municipal and industrial wastewater treatment due to the increasingly stringent ammonia effluent discharge regulations implemented by Canada, the United States, and the European Union. The objective of this dissertation is to develop new understanding and advance the current design and operation of total ammonia nitrogen (TAN) removal via the moving bed biofilm reactor technology (MBBR) for municipal and industrial wastewaters. The first specific objective is to develop a passive, low operationally intensive, efficient and robust design strategy for municipal wastewater treatment to achieve partial nitritation (PN) as a pre-treatment to anammox treatment without using control strategies such as operating at low dissolved oxygen, or the use of inhibitors. This first objective includes developing new knowledge of the biofilm, biomass and microbiome of attached growth PN systems. The second specific objective is to investigate the impact of defining a maximum biofilm thickness, via bio-carrier design, to enhance the effects of free nitrous acid inhibition for PN of municipal wastewaters. The third objective is to investigate the effect of influent copper concentration on nitrifying MBBR systems over long-term operations, to demonstrate the feasibility of the nitrifying MBBR as a solution for TAN removal from gold mining wastewaters. The results pertaining to the first objective, achieved via a study investigating the operation of a nitrifying moving bed biofilm reactor at elevated TAN surface area loading rates (SALRs) of 3, 4, 5, and 6.5 g TAN/m²∙d with the aim of achieving passive PN, demonstrates that operating at a TAN SALR value of 6.5 g TAN/m²∙d can achieve PN without restricting dissolved oxygen or using inhibitors. Operating at a TAN SALR value of 6.5 g TAN/m²∙d achieves a TAN surface area removal rate (SARR) of 3.5 g TAN/m²∙d, and a nitrite accumulation of 99.8% of the oxidized TAN, demonstrating the suppression of nitrite oxidizing bacteria (NOB) activity, while achieving elevated TAN SARR values. At the molecular-scale, there is a statistically significant change in the ammonia oxidizing bacteria (AOB) to NOB ratio from 1:2.6 to 8.7:1 as the TAN SALR increases from 3 to 6.5 g TAN/m²∙d; however, even at a TAN SALR value of 6.5 g TAN/m²∙d there is an NOB abundance of approximately 2%; thus demonstrating that NOB remain present in the biofilm, while their activity is suppressed by operation at elevated TAN SALR values. Furthermore, this system was shown to achieve stable PN consistently for over a period of 10 months of operation, demonstrating a robust, passive, low operational strategy for attached growth PN. The second objective of this dissertation is addressed through a study that compared the carrier design of defined maximal biofilm thickness (z-prototype carrier) to undefined maximal biofilm thickness (chip-prototype carrier) for PN via free nitrous acid inhibition of tertiary, low carbon, municipal wastewaters. The study demonstrates that defined maximal biofilm thickness is a preferred design choice to achieve attached growth PN. The chip-prototype carrier shows biofilm thicknesses and biofilm mass values that are ten-fold higher than the z-prototype carrier, which is shown to contribute to the impact of free nitrous acid on AOB and NOB activities. The z-prototype carrier shows PN is achieved after 3 hours of exposure to free nitrous acid while the chip-prototype carrier does not achieve PN within this same time of exposure. Therefore, the defined maximal biofilm thickness carrier is identified in this research as the preferred design option to achieve attached growth PN for municipal, low carbon, tertiary wastewater treatment. The results of the third objective, achieved via a study investigating the effects of influent copper concentrations on nitrifying MBBR during long term operations to gold mining wastewaters, demonstrates that there is no AOB inhibition in attached growth systems exposed to 0.1, 0.3, 0.45, and 0.6 mg Cu/L for long exposure times. A trend of increasing nitrite accumulation with increasing influent copper concentrations is shown, indicating that NOB inhibition occurs at influent copper concentrations of 0.3 mg Cu/L and greater, with the greatest NOB inhibition observed with an influent copper concentration of 0.6 mg/L. There is no statistically significant difference in biofilm characteristics at the copper concentrations tested; however, there is a trend of increasing biofilm thickness and biofilm roughness with increasing copper concentrations. This study demonstrates the resilience of the nitrifying biofilm to copper inhibition and demonstrates that the nitrifying MBBR is a promising system for removing TAN in mining wastewater in the presence of copper.

Active sludge membrane bioreactor (AS-MBR) is a process of membrane separation of activated sludge. This is increasingly becoming an alternative for wastewater treatment plants as improved effluent quality often is required together with special limitations. A major drawback for the process is however membrane fouling, which needs to be further handled in order to create a cost-beneficial solution. Fouling can potentially be reduced by applying biofilm (BF) instead of activated sludge. Prospects of even more compact plants, with reduced aeration requirements, and improved effluent quality are other driving forces for investigation of BF-MBR. The limited literature concerning BF-MBR illustrates however varying degrees of success. The first part of this report presents the available knowledge on fouling in both AS-and BF-MBRs. The overall objective of this thesis was to carry out a comparison between membrane performances in the two systems. This was done by operating two equal pilot plants in parallel for several months, while water quality and fouling were measured. The results revealed less fouling and better treatment in the AS-MBR. Additionally, it was found that the AS-MBR reactor water contained significantly less submicron organic material which often is found to be an important foulant. In order to evaluate the impact on the membrane performance, the amount of suspended solid was increased in the BF-MBR. A clear improvement was found with increased amounts of suspended solids, and the finalexperiment indicated even better membrane performance when compared to the AS-MBR. Some suspended solid should therefore be present in order to form of a protective cake layer on the membrane surface and prevent other foulants from adsorbing directly to the membrane. The suspended solids may also flocculate the smaller foulant prior to deposition on the surface. Increased operating problems regarding BF sludge needs however further analysis. The results obtained in this study supports that the BF-MBR membrane can be operated just as well the AS-MBR, or maybe even better under the right circumstances. Configurations with increased amounts of suspended solid in an external membrane reactor should therefore further be evaluated, as well as the prospects of an optimum concentration of suspended solid.

Eutrophication is an imbalance of aquatic system functioning due to an uncontrolled discharge of nutrients, i.e. nitrogen (N) and phosphorus (P), in water bodies. European legislation has defined discharge limits for BOD5, COD and TSS for wastewater treatment plants (WWTPs) serving >2000 population equivalent (PE). Moreover, stringent nutrient-discharge limits have been set for treated effluents from WWTPs larger than 10000 PE discharging into sensitive areas. Nevertheless, for small communities (below 2000 PE), the current national directive (D. Lgs. n°152/2006) and European legislation does not oblige to respect the discharge limits required for larger communities, although strict purification values can be set at local level, mainly depending on the receiving water body (e.g. lake or river). Italy is characterized by the existence of a huge amount of low-populated locations, as almost 44% of the municipalities count less than 2000 inhabitants. Centralised wastewater treatment is not always feasible or the most cost-effective option for all sites due to geographical conditions and dispersed settlements. The aim of this doctoral thesis was to study a compact solution for the removal of C, N and P for the treatment of low- and medium-strength municipal wastewater that may help small communities to implement efficient and low-cost wastewater treatment. The combined removal of carbon and nutrients via simultaneous nitrification and denitrification (SND) coupled to P removal in moving bed biofilm reactors (MBBRs) was chosen as a potentially advantageous system for the scope as biofilm reactors enable the formation of a stratified biofilm with different microbial families depending on wastewater composition and operating conditions. Although satisfactory removal efficiencies have been achieved by operating single-stage MBBR as sequencing batch reactors (SBR) alternating anaerobic and aerobic/anoxic conditions, the MBBR-SBR technology is best suited to treat industrial wastewater, being discontinuously produced during the day, while a continuous-mode operation would be more suitable for municipal wastewater treatment. In this PhD work, SND coupled to P removal was investigated in continuous-flow single-stage MBBRs adopting different aeration strategies, i.e. stable microaerobic conditions and intermittent aeration (IA) conditions. The microaerobic conditions were set by maintaining a dissolved oxygen (DO) of 1.0 (±0.2) mg L-1, resulting in a simultaneous removal of COD, total inorganic nitrogen (TIN) and dissolved phosphorus (P-PO43-) with average efficiencies of 87%, 58% and 66% respectively, at feed C/N ratio of 4.2. At feed C/N ratio of 2.7, average TIN RE was 46% due to lack of electron donor for denitrification. At the same time, at feed C/N ratio of 5.6, excess overgrowth of heterotrophic aerobic bacteria (HAB) led to poor nitrification, determining an average TIN RE of 51%. Subsequently, aeration strategy was shifted from a continuous aeration mode to a microaerobic/aerobic IA condition. SND process and P removal were studied in a continuous-flow IAMBBR under different DO regimes (0.2–2, 0.2–3 and 0.2–4 mg L-1). Simultaneous removal of dissolved organic carbon (DOC), TIN and P-PO43- removal efficiencies of 100%, 62% and 75% were achieved at DO range at 0.2–3 mg L-1 and at feed C/N ratio of 3.6. The bacterial community composition of the IAMBBR biofilm was investigated by Illumina sequencing, revealing the coexistence of nitrifiers (Nitrosonomas and Nitrospira) and denitrifiers with P-accumulating ability indicated as putative PAO (Hydrogenophaga), which were abundantly detected throughout the entire study. As last step, the feasibility of coupling a simultaneous partial nitrification and denitrification (SPND) to P removal were studied in two continuous-flow IAMBBRs. The effect of feeding two different carbon sources, i.e. ethanol and acetate, on the reactor performances and microbial community composition was also investigated. The inhibition of nitratation phase (NO2-→NO3-) allowed to reach average DOC, TIN and P-PO43- REs of 100%, 81–88% and 83–86% at DO range of 0.2–3 mg L-1 and feed C/N ratio of 3.6. Finally, the effect of different feed C/P ratios (22 and 11) on P removal and microbial community of both biofilm and suspended biomass was studied. Illumina sequencing displayed the presence of putative PAOs such as Hydrogenophaga and Acidovorax, while typical NOB were never detected. MBBRs performing combined SPND and P removal achieved a 20% higher TIN RE compared to previous SND process under similar DO and C/N conditions. This work shows that efficient, simple and low-cost C, N and P removal can be achieved in MBBR by controlling the aeration pattern and at certain C/N/P ratios. Therefore, microaerobic/aerobic MBBRs are proposed as an interesting solution for implementing wastewater treatment in small communities.

Tiivistelmä. Oulun Veden Taskilan jätevedenpuhdistamolla otettiin käyttöön syksyn 2018 aikana MBR-tekniikkaa jätevedenpuhdistuksen tehostamiseksi sekä käsittelykapasiteetin lisäämiseksi. MBR eli kalvobioreaktori (englanniksi membrane bioreactor) on yhdistelmäprosessi, jossa aktiivilieteprosessin orgaanisen aineen poisto yhdistetään kalvosuodatuksen mekaaniseen lietteen poistoon. Taskilan MBR-yksikkö toimii perinteisen aktiivilieteprosessin rinnalla. Esiselkeytetystä vedestä noin 35 % käsitellään MBR-yksikössä ja loput perinteisessä aktiivilieteprosessissa. Tässä diplomityössä keskitytään kalvosuodatukseen ja MBR-tekniikkaan Taskilan jätevedenpuhdistamolla. Taskilan MBR-yksikkö muodostuu hienovälppäyksestä, kahdesta ilmastusaltaasta ja neljästä MBR-kalvosuodatuslinjasta. Kalvosuodatuksessa on käytössä onttokuitukalvot, joiden huokoskoko on 0,04 µm. Kalvojen kokonaissuodatuspinta-ala on liki 50 000 m², jolloin MBR-yksikön keskivirtaama on 864 m³/h. MBR-linjojen keskivirtaama riippuu veden lämpötilasta. Talvikaudella veden lämpötilan ollessa alle 10 °C, MBR-linjat suodattavat virtaamalla 216 m³/h. Välikaudella sekä kesäkaudella veden lämpötilan ollessa yli 10 °C, linjakohtainen virtaama on 288 m³/h. Suodatuskäytössä olevien linjojen lukumäärää ohjataan MBR-yksikön virtauspyynnin sekä ilmastusaltaan pinnankorkeuden mukaan. Tällöin suodatuskäytössä on samanaikaisesti 2–4 MBR-linjaa. Kalvot ovat herkkiä isoille partikkeleille sekä mekaaniselle kulutukselle. Hienovälppäys on siten erityisen tärkeä vaihe MBR-yksikön alussa. Kalvojen puhtaanapito sekä likaantumisen ja tukkeutumisen ennaltaehkäisy ovat tärkeässä roolissa suodatuksen toimintatehokkuuden ylläpitämisessä. Suodatuksen aikainen kalvoilmastus sekä ajoittainen vastavirtahuuhtelu irrottavat kiintoainetta kalvojen pinnalta. Lisäksi MBR-linjoille suoritetaan kemiallisia pesuja. Ylläpitopesuja suoritetaan viikoittain 1–3 kertaa ja liuotuspesuja huoltotoimenpiteenä 1–2 kertaa vuodessa. Pesukemikaaleina voidaan käyttää natriumhypokloriittia tai sitruunahappoa. Käyttöönoton jälkeen loka-joulukuussa 2018 MBR-yksikön puhdistustulokset ovat olleet erittäin hyviä verrattuna lupaehtoihin sekä perinteisen aktiivilieteprosessin tuloksiin. MBR-lähtevä vesi on miltei kiintoainevapaata. Lisäksi fosfori, COD ja BOD ovat poistuneet todella tehokkaasti. Bakteerianalyysien perusteella kalvosuodatus poistaa tehokkaasti myös E. coli -bakteerit sekä suolistoperäiset enterokokit. Työssä käsitellään puhdistustuloksia kiintoaineen, kokonaisfosforin, kokonaistypen, CODcr:n sekä BOD7ATU:n osalta. Lisäksi työssä esitellään bakteerianalyysejä sekä Euroopan päästörekisterin mukaiset analyysit. MBR on uusi tekniikka Suomen haastavissa ja muuttuvissa ilmasto-olosuhteissa. Kevään kylmät sulamisvedet, kesäaikainen typenpoisto sekä syyssateet luovat omat haasteensa kalvosuodatukselle, mutta vaativat myös erilaisia ratkaisuja. Taskilan MBR-yksikön tulokset ja prosessin toiminta erilaisissa olosuhteissa ovat arvokasta kokemusta mahdollisille uusille MBR-laitoksille Suomessa ja Pohjoismaissa.MBR technology in Taskila wastewater treatment plant. Abstract. Oulu Waterworks upgraded Taskila Wastewater Treatment Plant by installing MBR technology. During the autumn 2018 MBR technology was launched for more efficient wastewater treatment and increasing the plant capacity. Membrane bioreactor (MBR) is a combination process where the organic matter removal in activated sludge process is combined with the mechanical sludge removal in membrane filtration. In Taskila WWTP, the MBR unit operates alongside the conventional activated sludge process. Approximately 35% of the pre-sedimented wastewater is treated in the MBR unit and rest in the conventional activated sludge process. This Master’s Thesis is focused on membrane filtration and MBR technology in Taskila Wastewater Treatment Plant. Taskila MBR unit consists of fine screening, two aeration basins and four MBR trains. Hollow fiber membranes with the pore size of 0.04 µm are used in the filtration process. Total filtration area in Taskila MBR unit is almost 50 000 m² and the average daily flow of the MBR unit is 864 m³/h. The average daily flow of the individual MBR train is dependent on the water temperature. During the winter period (water temperature < 10 °C), the average daily flow of the MBR train is 216 m³/h. During the interim period (water temperature 10 °C ≤ T < 12 °C) and the summer period (water temperature ≥ 12 °C), the average daily flow of the MBR train is 288 m³/h. The number of trains in production is calculated based on the plant demand and the water level in aeration basins. There are 2–4 trains in production (filtrating) at the same time. Membranes are sensitive for large particles and mechanical wear. Fine screening is thus a particularly important step at the beginning of the MBR unit. Membrane cleaning and prevention of fouling and clogging play an important role in maintaining the efficiency of filtering. Solid matter can be removed from the membrane surface with constant membrane aeration and with backpulse. In addition, there are chemical cleanings for the membranes. Maintenance clean is done 1–3 times a week for every MBR train and recovery clean is done 1–2 times a year for each train. Sodium hypochlorite and citric acid can be used for the cleanings. After the commissioning in October–December 2018, purifying results of the MBR unit has been very good compared to requirements and results of the conventional activated sludge process. MBR permeate is almost free from suspended solids. In addition, phosphorus, COD and BOD have been removed extremely effectively. Based on the bacteria analysis, membrane filtration has removed E. coli and enterococcus bacteria effectively from wastewater. In this Thesis, purifying results considering suspended solids, total phosphorus, total nitrogen, CODcr and BOD7ATU are presented. In addition, bacteria analysis and analysis for European Pollutant and Transfer Register are considered. MBR is a new technology in Finland and its challenging and changing climate. Cold melting waters in spring, total nitrogen removal in summer and the autumn rains create their own challenges for membrane filtration, but also require different solutions for the process. The results from the Taskila MBR unit and the operation of the process under different conditions will give valuable experiences for potential new MBR plants in Finland and in the Nordic countries.

Bakgrund: Mindfulness är ett nytt koncept inom omvårdnad. Mindfulness-based stress reduction (MBSR) är ett program som utvecklats från mindfulness inom vården. MBSR har studerats i samband med olika sjukdomar däribland cancer. Bröstcancer är den vanligaste maligna cancern hos kvinnor världen över och att få en cancerdiagnos medför både fysiska och psykiska svårigheter. Syfte: Att beskriva effekter av MBSR på personer med bröstcancer. Metod: Litteraturöversikt baserad på RCT-studier (randomised controlled trials). Datainsamling gjordes via CINAHL, Medline och PsychINFO och tolv RCT-studier granskades med en induktiv ansats. Resultat: Resultatet bygger på tolv RCT studier som jämför MBSR med vanlig behandling (VB) och är indelat i effekter avseende fysiskt välmående, effekter avseende psykiskt välmående, effekter avseende hantering och effekter avseende socialt välmående. Slutsats: Generellt finns kortsiktiga positiva effekter till följd av MBSR-programmet hos personer med bröstcancer. Dock är dessa effekter ofta uppmätta direkt efter interventionen och flera studier visar att dess effekt minskar efter tolv månader. Evidensen för att använda MBSR i vården av personer med bröstcancer är ännu låg och fler studier med längre uppföljning bör göras.
Background: Mindfulness is a fairly new concept in nursing. The MBSR-programme (Mindfulness based stress reduction) was developed from mindfulness in healthcare. MBSR has been studied in relation to different healthcare settings and illnesses there among cancer. Breast cancer is the most common cancer amongst women worldwide. To live with cancer entails both psychological and physical issues. Aim: To describe the effects of MBSR on persons with breast cancer. Method: A literature review based on RCT-studies (randomised controlled trials). Data collection was done using CINAHL, Medline and PsychINFO and twelve RCT-studies was examined with an inductive approach. Results: The result is based on twelve RCT-studies comparing MBSR with standard treatment and presented in effects related to: physical wellbeing, psychological wellbeing, coping and social wellbeing. Conclusion: Generally, there are short term positive effects of the MBSR-programme on persons with breast cancer. These effects are often measured directly after the intervention and several studies show that the effects diminish after twelve months. Evidence to use MBSR in healthcare for persons with breast cancer is still low and more studies with longer follow up should be conducted.

Cette thèse propose un modèle dynamique d'un bioréacteur à membrane submergée (sMBR) comprenant les comportements physiques et biologiques du processus. La filtration (aspect physique) est un modèle de résistances en série composé de la résistance réversible (liée au processus de formation d'un gâteau qui peut être enlevé par lavage de l'air) et de la résistance à colmatage irréversible. La fonction biologique est mise en œuvre par l'extension du modèle de chemostat simple avec un mécanisme de filtration.L'analyse du modèle comprend : l'analyse asymptotique, l'observabilité, la contrôlabilité et l'étude dynamique lente et rapide. Cette dernière, basée sur le théorème de Tikhonov, révèle la possibilité de simplifier la dynamique du modèle en découplant le processus en trois échelles de temps : l'évolution du colmatage à long terme (dynamique lente), la dégradation biologique ( dynamique rapide) et la formation du gâteau (dynamique ultrarapide). Comme les processus avec sMBRs sont relativement nouveaux, les données réelles de processus sont difficiles à obtenir. Ainsi, une installation pilote d'un système de recirculation de l'aquaculture avec une sMBR est conçue, construite et automatisée. Des mesures en ligne du processus, tels que la température, les matières en suspension (MES), l'ammoniac et les concentrations des effluents nitrates, la croisée de l'air et des débits d'effluents et la pression transmembranaire, sont réunis afin de valider le modèle proposé.Pour mettre en évidence le cadre général du modèle proposé, le même modèle est composé d'ensembles de données réelles obtenues à partir d'une installation de traitement des eaux usées à sMBR. Par conséquent, une identification de paramètre est organisée en trois étapes correspondant aux trois échelles de temps obtenues à partir de l'analyse analytique. L'identification de paramètre est implémentée en utilisant une fonction de coût aux moindres carrés pondérés et l'inverse de la Fisher Matrix Information (FIM), qui est utilisé pour obtenir les intervalles de confiance des paramètres calculées par une borne inférieure sur la matrice de covariance des estimations des paramètres. La capacité du modèle à prédire la pression transmembranaire et la dégradation biologique est prouvée par la validation du modèle et la validation croisée des résultats.Concernant le contrôle du processus, deux approches différentes sont utilisées : un contrôleur partielle linéaire basé sur la théorie de Lyapunov est conçu afin de stabiliser la production encrassement en actionnant dans la croisée de l'air et les flux d'effluents; une commande prédictive de modèle non linéaire (NMPC) est mise en œuvre afin d'optimiser le taux de production d'effluent et de maximiser la période entre deux opérations de lessivage chimique.Les résultats présentés dans cette thèse montrent l'importance des études analytiques sur des modèles afin de traiter la cognition et la simplification de modèle. Un autre point important est la structure du modèle dynamique simple avec une petite quantité de paramètres. Ce travail montre que cette structure est suffisante pour mettre en œuvre des stratégies de contrôle avancé sur les processus sMBR et même de prédire la dégradation biologique et la dynamique de croissance du colmatage
This thesis proposes a simple submerge membrane bioreactor (sMBR) dynamic model that comprises physical and biological process behaviors. The filtration, physical aspect, is a resistance-in-series model that is composed with reversible resistance, linked to sludge cake formation process that can be detached by air scouring, and the irreversible fouling resistance. The biological feature is implemented extending the simple chemostat model to the filtration mechanism. The model asymptotic analysis, observability, controllability and fast and slow dynamic study are carried out. The latter, based on the Tikhonov's theorem, reveals the possibility to simplify model dynamics by decoupling the process in three time scales, i.e. long-term fouling evolution (slow dynamic), biological degradation (fast dynamic) and fouling cake formation (ultrafast dynamic). As sMBR processes are relativity new, real process data are scarce. Thus, a recirculating aquaculture system pilot plant with an sMBR is design, build and automated. Process online measurements such as: temperature, total suspended solids (TSS), ammonia and nitrate effluent concentrations, air cross- and effluent flow rates and trans-membrane pressure are gathered in other to validate the proposed model. To evidence the model general framework the same model is confronted with real data sets obtained from an sMBR wastewater treatment plant. Therefore, a parameter identification is organized in three steps corresponding to the three time scales obtained from the analytical analysis. The parameter identification is implemented using a weighted least-squares cost function and the inverse of the Fisher Information Matrix (FIM), which is used to obtain the parameters confidence intervals, is computed by a lower bound on the covariance matrix of the parameter estimates. The model capacity to predict trans-membrane pressure and biological degradation is proved by model validation and cross-validation results, in which an accurate correlation coefficients (R^2) of approximately 0.83 are obtained. Concerning the process control, two different approach are used: a partial-linearizing feedback Lyapunov controller is designed in order to stabilize the fouling production by actuating in the air cross- and effluent flows; and a nonlinear model predictive control (NMPC) is implemented in other to optimize the effluent production rate and maximize the period between two chemical cleaning procedures. The results included in this thesis show the importance of analytical model studies in order to process cognition and model simplification. Another important point is the simple dynamic model structure, with a small quantity of the parameters, which is adequate to implement advanced control strategies on sMBR processes and, similarly, to predict biological degradation and fouling build-up dynamics

Hälso- och sjukvården har traditionellt arbetat kurativt. Tidigare forskning har visat att samhällsutvecklingen de senaste 20 åren, med högt tempo och stora krav, har resulterat i en ökning av stressrelaterad ohälsa, både nationellt och internationellt. Vinsterna med att arbeta hälsofrämjande är uppmärksammat i allt fler studier och det är därför av relevans att studera om Mindfulness-Based Stress Reduction (MBSR), en förgrening av mindfulness, kan fungera som en effektiv och bidragande resurs för ett mer begripligt, hanterbart och meningsfullt liv. Syftet med denna litteraturstudie var att belysa de hälsofrämjande effekterna av MBSR. Tio artiklar valdes för granskning och utifrån artiklarnas resultat framkom två kategorier: Kortvariga hälsofrämjande effekter och långvariga hälsofrämjande effekter. Resultatet visade att MBSR har hälsofrämjande effekter, både ur ett kortvarigt och långvarigt perspektiv. Genom kontinuerligt utövande av MBSR ökar självkännedomen och medvetenheten, vilket resulterar i större hanterbarhet i vardagen och utövarna upplever en större meningsfullhet. Den mängd och bredd av olika hälsofrämjande effekter som uppmärksammats i denna litteraturstudie bör vara indikation på vidare forskning för fler användningsområden samt motivationens inverkan på utövande. Fler studier bör även inkludera ett samhällsperspektiv där de kostnadseffektiva aspekterna av MBSR undersöks.
Health services have traditionally worked curative. Previous studies have shown a societal development during the last 20 years, indicating an increased pace and great demands that results in decreased health due to stress, nationally as well as internationally. However, the benefits of working with health promotion is noted in more and more studies and therefore it is relevant to study whether MBSR, a further development of mindfulness, can be used as an effective resource in order to contribute and achieve a more comprehensible, manageable and meaningful life. The purpose of this study was to examine the health effects of MBSR. Ten articles were selected for review and based on the results collected from all articles, two categories were revealed: Short-term health benefits and long-term health effects. The results showed that MBSR has health effects, from both a short-term and long-term perspective. Through continuous pursuit of MBSR increases self-knowledge and awareness, resulting in greater manageability of everyday life and practitioners experience a greater meaningfulness. The variety and breadth of various health promoting effects that was highlighted in this literature study might indicate further research regarding more uses and how motivation influence the amount of exercise and effect. More studies should also include a societal perspective, where the cost aspects of MBSR are investigated.

This study details a genetic investigation of ecgonine degradation by P. fluorescens MBER. Transposon (Tn5) insertional inactivation mutagenesis was performed to create mutants blocked in the ecgonine degradative pathway. By this method, 87 such mutants were isolated and analysed to identify where in the genome the interruption had occurred. At the whole cell and cell-free extract level, no intermediary metabolites were detected in these mutants by either TLC or GC/MS analysis. The genetic location of Tn5 in the DNA was therefore investigated to obtain sequence data around the insertion site which might identify the gene into which insertion occurred. This genetic analysis revealed that the transposon had inserted in an identical fragment in all 87 mutants, indicating a hyper-insertion region in the DNA. Sequence data flanking the insertion site did not exhibit homology to any known sequences in world-wide databases; the identity of the interrupted gene currently remains unknown. Co-isolated with the unidentified sequence, however, was DNA exhibiting high homology to a phenol hydroxylase, and a benzene monooxygenase. Initial enzyme induction studies revealed that the meta-cleavage pathway associated with catechol metabolism in P. fluorescens MBER was induced by growth on ecgonine as the sole source of carbon. Putative evidence obtained during the course of this study infers that aromatic degradative enzymes may be involved in the later stages of ecgonine degradation. The results obtained are also discussed in the light of subsequent work, which discovered the unidentified DNA interrupted by Tn5 insertion resulting in loss of ecgonine degrading ability was not co-located with the putative benzene monooxygenase and phenol hydroxylase.

This thesis explores the transformation of the Buddhist technique of mindfulness as it is applied in psychotherapy. It is based on primarily on the experience of a Mindfulness-based stress reduction (MBSR) course as taught in Montreal in 2015, as well as some prior experiences of mindfulness meditation at the Palyul Center and Acceptance and Commitment Therapy in Ottawa. Written as an auto-ethnography, the thesis provides an intimate first hand immersion experience into mindfulness meditation through a phenomenological approach in anthropology. The sociopolitical aspects of MBSR are also discussed through a related Deleuzo-Guattarian framework. The central argument of the thesis is that while effective in the management of stress MBSR fails to address deeper and more severe forms of suffering, stressing the management of emotions rather than their exploration. This fact coupled with the omission of the Buddhist concept of no-independent self and training in mindfulness results in MBSR being a territorializing force of self-surveillance and a social pacifier .The question emerging from this exploration brings us to revisit the role of ethics in the application mindfulness in therapy.

Younger breast cancer survivors often report problems related to sexuality following surgical and adjuvant treatment that often lead to sexual distress and body image distress. This research was conducted as an exploratory study within a larger R01 trial with the purpose to evaluate sexual distress and body image related-distress in younger women with breast cancer and to examine the extent to which the Mindfulness-Based Stress Reduction-Breast Cancer (MBSR(BC)) was efficacious in improving distress related to sexuality, i.e. sexual distress and body image related-distress. The aims of this study were to: 1) evaluate the efficacy of the MBSR(BC) program in improving the psychological symptoms of sexual distress and body image related distress; and 2) evaluate whether positive effects achieved from the MBSR(BC) program are modified by specific patient characteristics measured at baseline. Ninety-one participants were randomized to either the MBSR(BC) intervention or Usual Care (UC) and assessments were conducted at baseline, 6-week and 12-week follow-up for sexual distress, body image related distress, demographic data as well as clinical history. For aim 1, analysis of covariance (ANCOVA) and linear mixed model (LMM) analysis were the methods used to evaluate the efficacy of the MBSR(BC) program. For aim 2, ANCOVA and stepwise multiple linear regression were used to evaluate the patient characteristics at baseline that modified the effects achieved from the MBSR(BC) program. Results showed the mean age of the sample was 57 years and 74% were White, non-Hispanic. Chi square analyses found that there were no significant differences between the MBSR(BC) and UC groups on baseline demographic or clinical characteristics. For Aim 1, results of the ANCOVA analyses found that there was no significant difference between the MBSR(BC) and UC groups at the 6-week follow-up on sexual distress or body image related distress (both p > .05). However, ANCOVA analyses found that there was a significant relationship between baseline scores and scores at the 6-week follow-up for both sexual distress (p < .0001) and body image related distress (p < .0001). Further ANCOVA analyses for Aim 1 found that there was a trend towards a statistical significance for the difference between the MBSR(BC) group and UC groups at the 12-week follow-up for both sexual distress (p = .09) and body image related distress (p = .06). Results of the Linear Mixed Model (LMM) analyses, implemented to assess sexual distress over time, showed a significant main effect (ME) of time (p < .000) and a trend towards significance for the time by assignment interaction (p = .104). The LMM analyses for body image disturbance resulted in a significant ME of (p < .000) and an interaction that approached significance (p = .071). For aim 2, ANCOVA results found that age at baseline was a significant predictor of change at 6 weeks in levels of body image related distress (p = .007), but no relationship was observed for sexual distress. Further, analysis using a stepwise multiple linear regression analysis found age at baseline to be the only significant predictor of both baseline sexual distress (p = .004) and baseline body image related distress (p = .008). Although the MBSR(BC) program was not tailored for integrating sexuality content, results of this stress reducing program (MBSR(BC)) program, adapted for breast cancer survivors, appeared to benefit these young women. The findings of this study identify that there is a need for stress reducing interventions addressing problems related to sexual distress and body image related distress. In addition, these results identified that clinically, BCS should be assessed for sexual distress and body image disturbance post-treatment, and interventions to assist with this distress should be incorporated into their plan of care.

Sydvästra stockholmsregionens va-verksaktiebolag – Syvab äger och driver Himmerfjärdsverket som just nu genomgår en storskalig om- och utbyggnad för att kunna hantera både ökad belastning och de strängare reningskrav som förväntas i framtiden. Reningsverket kommer att byggas om till en MBR-process, d.v.s. MembranBioReaktor. I samband med det här har en MBR-pilotanläggning tagits i drift. I pilotanläggningen fördelas avloppsvattnet i tre på varandra följande s.k. kaskader som vardera är utrustade för fullständig kväverening.  Syftet med detta projekt var att undersöka varför det observerats lägre denitrifikationshastigheter i pilotanläggningen jämfört med dimensionerande data vid tillsats av extern kolkälla (metanol). För att undersöka detta utfördes först en litteraturstudie för att få förståelse för processerna samt vilka parametrar som påverkar denitrifikationen.  Därefter gjordes tre olika typer av försök. Det ena var efterdenitrifikationsförsök som gjordes för att följa upp den maximala denitrifikationshastigheten i slammet. Det andra testet undersökte det linjära sambandet för denitrifikationshastighetens temperaturberoende. Slutligen gjordes kväveprofiler för att beräkna momentana denitrifikationshastigheter i processen genom att ställa upp massbalanser över de analyserade parametrarna. Data från resultaten utvärderades tillsammans med tidigare insamlade data från pilotanläggningen.  Resultaten från både efterdenitrifikationsförsöken och kväveprofilerna visade att denitrifikationshastigheten var lite högre än tidigare försök som gjorts (maximalt uppnåddes 2,0 mg NO3/gVSS, h) men fortfarande lägre än den dimensionerande hastigheten på 3,5 mg NO3/gVSS, h. Enligt temperaturförsöken som gjordes ökar denitrifikationshastigheten med 10,3% per °C.  De högre hastigheterna tros till viss del bero på högre temperatur men främst på lägre syrehalter i processen vilket kan ha förändrat bakteriesammansättningen i slammet till fördel för denitrifikationen. Utifrån försöken som gjorts verkar den dimensionerande denitrifikationshastigheten vara orimligt hög.
Sydvästra stockholmsregionens va-verksaktiebolag – Syvab owns and operates the Himmerfjärdsverket plant, which is currently undergoing a large-scale refurbishment and expansion to cope with both increased loadings and the stricter treatment requirements expected in the future. The plant will be converted to an MBR process, i.e. Membrane BioReactor. In conjunction with this, an MBR pilot plant has been commissioned. In the pilot plant, the wastewater is distributed in three successive cascades, each equipped for complete nitrogen removal.  The aim of this project was to investigate why lower denitrification rates were observed in the pilot plant compared to the design data when an external carbon source (methanol) was added. To investigate this, a literature study was first carried out to gain an understanding of the processes and the parameters affecting denitrification.  Thereafter three different types of experiments were performed. One was a post- denitrification experiment to monitor the maximum denitrification rate of the sludge. The second test examined the linear relationship for the temperature dependence of the denitrification rate. Finally, nitrogen profiles were made to calculate denitrification rates in the process by setting up mass balances over the analysed parameters. The data from the results were then evaluated together with previously collected data from the pilot plant.  The results from the post-denitrification experiments and the nitrogen profiles showed that the denitrification rate was faster than in the previously performed experiment (maximum of 2,0 mg NO3/gVSS, h was achieved) but still lower than the designed rate for the process of 3,5 mg NO3/gVSS, h. According to the temperature experiments performed, the denitrification rate increases by 10.3% per °C.  The faster denitrification rates can be explained partly due to higher temperatures in the process but mainly due to lower oxygen levels in the process which may have altered the bacterial composition of the sludge in favor of denitrification. Based on the experiments carried out, the designed denitrification rate appears to be higher than what can be achieved in the pilot plant.

This diploma thesis is focused on the topic of membrane technologies used in wastewater treatment. The research part of the thesis deals with membrane separation of activated sludge, and the focus is on the submerged membrane modules. The thesis contains basic principles of MBR systems, an overview of used membrane modules, modes of operation, advantages and disadvantages of using this process. The practical part of the thesis proposes the intensification of WWTP Perná with using MBR technology. This part includes the technical-economic assessment of the activation WWTP with the third stage of treatment and activation WWTP with MBR.