Dissertations / Theses on the topic 'Effluent treatment'

The objective of this study was to investigate the anaerobic biological treatment of an organic-bearing wastewater from a particular paper manufacturing process at laboratory scale. The process produces paper by re-pulping waste paper. Effluent from the process has a Chemical Oxygen Demand (COD) concentration of approximately 4500 mg/l with a sulphate content of approximately 300 mg SO₄²⁻/l. The upflow anaerobic sludge bed (UASB) reactor was selected for the study. Important information derived from the laboratory treatability study was: (l) the extent of COD removal possible; (2) the effluent quality; (3) the maximum COD leading rate (kgCOD/m³ reactor/day) which can be achieved while maintaining reasonable COD removal, and the influence on loading rate of temperature: (4) the nature of the sludge produced in the reactor with particular reference to the extent of pelletisation: and (5) the effect of reactor effluent recycling on alkalinity requirements.

FundaÃÃo Cearense de Apoio ao Desenvolvimento Cientifico e TecnolÃgico
The current investigation aimed to study post-treatments for effluents of anaerobic sludge blanket reactors by using both natural (Moringa oleifera, Lam) and unnatural coagulants. For that, many jar-tests were conducted either using sewage or effluent of a lab-scale UASB (upflow anaerobic sludge blanket) reactor. Many dosages of natural (Moringa oleifera) and unnatural (ferric chloride) coagulants were tested with sewage. Afterwards, the coagulants effect associated to a polymer (FO 4140) was assessed in the physical-chemical and microbiological parameters of the UASB reactor effluent. The results indicated that the natural coagulant moringa provided low turbidity removal in comparison with the unnatural coagulant ferric chloride, for both sewage and UASB effluent, questioning the real application of moringa in the physical-chemical treatment of sewage. Additionally, a negative effect of the moringa seeds was verified after the detection of a considerably increase of the Chemical Oxygen Demand (COD) and turbidity, while testing the UASB effluent. The results show that, in general, the moringa seeds were inefficient on the removal of physical-chemical and microbiological contaminants present in sewage and anaerobic effluents.
O presente trabalho teve como objetivo estudar pÃs-tratamentos de efluentes provenientes de reatores anaerÃbios de manta de lodo pelo uso de coagulantes naturais (Moringa oleifera, Lam) e nÃo naturais. Para tanto, foram realizados vÃrios ensaios de jar-test utilizando tanto esgoto sanitÃrio bruto quanto efluente de um reator UASB (upflow anaerobic sludge blanket) em escala de laboratÃrio. Foram testadas vÃrias dosagens dos coagulantes natural (Moringa oleifera) e nÃo-natural (cloreto fÃrrico) utilizando esgotos brutos domÃsticos. Em seguida foram estudados os efeitos dos coagulantes associados ao auxiliar de coagulaÃÃo (FO 4140), nos parÃmetros fÃsico-quÃmicos e microbiolÃgicos do efluente do reator UASB. A partir dos resultados, verificou-se que o coagulante natural moringa forneceu baixas remoÃÃes de turbidez na comparaÃÃo com o coagulante nÃo-natural cloreto fÃrrico, tanto para o esgoto bruto como para o efluente do reator UASB, questionando-se a real aplicaÃÃo da moringa no tratamento fÃsico-quÃmico de esgoto sanitÃrio. Adicionalmente, verificou-se um efeito negativo do uso das sementes de moringa, mediante a detecÃÃo de um aumento considerÃvel nas concentraÃÃes finais de DQO e turbidez, quando o efluente anaerÃbio era testado. Os resultados mostraram que, de uma forma geral, a semente de moringa se mostrou ineficiente na remoÃÃo de contaminantes fÃsico-quÃmicos e microbiolÃgicos presentes em esgotos sanitÃrios brutos e efluentes anaerÃbios.

To avoid the spread of disease from sewage treatment effluents, pathogenic microorganisms present must be destroyed by one or a combination of disinfection methods. Chlorine remains the predominant disinfectant used although it consumes considerable amounts of energy and has associated exposure risks from production, transportation and storage of this poisonous gas. In addition to bacteria and other objectionable microorganisms, color, suspended and colloidal solids also require removal from water for reuse. Aluminum and iron additions have been used to coagulate and remove non-settleable solids. By electrically dissolving aluminum to form solids-bridging aluminum hydroxide, the water itself can also be disinfected by the effects of electrical fields and its reactions to form disinfectant chemicals and direct destruction of microorganisms in the water. This research investigated the effects of electrical current, time, and chloride concentration on the electrochemical disinfection of sewage treatment plant effluent using aluminum electrodes to substitute for chlorine disinfection.

The increasing cost of effluent treatment in the wool scouring industry is rapidly becoming a determining factor in the viability of existing scouring operations and new installations alike. This thesis details the development of an integrated effluent treatment process capable of treating the worst polluted effluent from a wool scour "heavy flow-down", to the point where it can either be economically discharged to local trade waste sewer, or directly discharged to river or ocean outfall with minimal environmental impact. The existing proprietary chemical flocculation process, Sirolan CF™, was improved by the addition of a bio-flocculation stage and turbidity monitoring and control, and the product from this process fed to an aerobic biological treatment system based upon the traditional activated sludge process. The biological treatment process was found to remove up to 98% of the BOD5 loading from the pre-treated liquor with a hydraulic residence time of at least 50 hours being required in the aerobic digestion vessels. A residual biorefractory COD of approximately 3,600mg/L was identified which could not be removed by biological treatment. When operating continuously, the biological process was observed to metabolically neutralise the pH 3.0 - 4.5 feed from the chemical flocculation system to pH > 7.0 without the need for supplemental addition of neutralising agents such as sodium hydroxide. This in itself provides a significant economic incentive for implementation of the process. Kinetic analysis of the biological process carried out under controlled laboratory conditions using a Bioflo 3000 continuous fermentor showed that the bio-chemical process followed substrate inhibition kinetics. An appropriate kinetic model was identified to represent the behaviour of the substrate degradation system, and modified by inclusion of a pseudo toxic concentration to account for the effect of pH inhibition upon the biological growth rate. The process was verified both at pilot plant scale and at demonstration plant scale at an operational wool scour. The demonstration plant was of sufficient size to handle the full heavy effluent flow-down from a small wool scour. At the time of publishing three full-scale effluent treatment systems based on this research had been sold to both domestic and international clients of ADM Group Ltd. who funded the research.

The discharge of untreated aquaculture effluent can pollute receiving water bodies. I tested the feasibility of using salt-tolerant plants (halophytes) with potential as forage and oilseed crops, as biofilters to treat saline aquaculture effluent. Plants were grown in draining lysimeters in greenhouses and irrigated with effluent salinized with NaCl. Irrigation water came from a recirculating tilapia culture system. I measured yield potential, water use and capacity for nitrogen and phosphorus uptake. In Experiment 1, Suaeda esteroa, Salicornia bigelovii and Atriplex barclayana (Chenopodiaceae) were grown in sand in 0.02 m³ lysimeters. Plants were irrigated with effluent of 0.5 ppt, 10 ppt and 35 ppt salinity, to meet evapotranspiration demand and to allow 30% of the applied water to leach past the plant root zone. Despite the high leaching fraction and short residence time of water in the pots, the plant-soil system removed 98% and 94% of the applied total and inorganic nitrogen, respectively, and 99% and 97% of the applied total and soluble reactive phosphorus respectively. For all species, salt inhibited (P ≤ 0.05) the growth rate, nutrient removal, and volume of water the plants could process. The salt marsh species S. esteroa and S. bigelovii performed better than the desert saltbush, A. barclayana, at 35 ppt. In Experiment 2, Suaeda esteroa, was grown in lysimeters containing approximately 0.8 m³ sandy loam soil and irrigated three times per week with 31 ppt NaCl effluent. I used five irrigation treatments, ranging in volume from 50 to 250% of the potential evaporation rate. Plant biomass and water consumption increased significantly (P ≤ 0.05) with increasing irrigation volume. Nitrate concentrations in water draining from the lysimeters decreased during the experiment, and were significantly lower in the high-volume treatments than in the low-volume treatments. Phosphorus concentrations in the leachate water increased during the experiment as a function of increasing irrigation volume. Irrigating halophyte crops with aquaculture wastewater of seawater-salinity may be a viable strategy for disposal of effluent.

This study focussed on extending and applying techniques to measure hydrodynamic characteristics in treatment units at sewage works. Use was made of tracer dye studies and a spreadsheet based analysis tool. The resulting infonnation about residence time, tank conguration and pathological behaviour was linked to other infonnation from respirometry and flow and load studies. Characterising the wastewater process will become increasingly important as the economic and compliance drivers in the operation of wastewater treatment facilities become increasingly pronounced. Case studies at Royton WWTW, Chorley WWTW, Preston WWTW and Montebello WWTW were used to develop, improve and apply the methodology. Tests at Royton and Chorley were used to develop the practical side of conducting tracer studies. The Preston case study was used to improve the diagnostic methodology. It was demonstrated that consent failures as a result of events are usually a result of a number of (linked) factors, in the case of Preston influenced by the tank conguration. The response of a pulse of dye was measured at Preston in vessel outlet throughout the works. The tracer dyeresponse was used to predict the response to a discharge of high ammoniacal leachate liquor and compared to measured data. This type of calibration experiment facilitated the simulation of different discharge event scenarios. The tracer and modelling techniques were incorporated in a general diagnostic methodology, which caters for a phased approach in diagnostic studies. A series of diagnostic tables take the user through cause - effect hypotheses and possible measurement techniques to use in the diagnostic investigation. Although the diagnostic methodology proved to be a versatile asset optimisation tool, which required considerable less effort than deterministic models, implementation in United Utilities' AMP3 Capital Investment Programme was problematic. The size of the programme and lack of resources forced the company to implement standard rather than tailor-made solutions. However, the diagnostic methodology can easily be applied elsewhere in the wastewater industry.

When secondary sewage effluent is converted to snow, the nutrients and residual organics become concentrated in the early meltwater discharge through melt-freeze processes within the snow-pack. The early season melt comes off relatively slowly. Providing the soil can absorb the early melt, the bulk of the nutrients will be removed even if later season melt rates exceeds the soil's infil-trability. This could provide an inexpensive method for nutrient removal from secondary sewage effluents. Laboratory experiments showed that the degree of impurity concentration was largely independent of the number of diurnal melt-freeze cycles, snow depth, snow temperature and initial concentration of impurity in the snow. As a result, the removal of impurities from a snowpack can be expressed in terms of the cumulative melt discharge. A simple exponential decay process was found to describe the impurity removal well for most cases. The first 20% of the melt removed, on the average, 65% of the phosphorus and 86% of the nitrogen from snow made from sewage effluent; and 92% of the potassium chloride from snow made from potassium chloride solution. Stripping of ammonia during snow production and melting increased the overall nitrogen removal to about 90%. A field investigation of salt movement through a natural snowpack confirmed the laboratory results.
Applied Science, Faculty of
Civil Engineering, Department of
Graduate

Content: Sustainable tannery effluent treatment system in achieving required discharge standards including Total Dissolved Solids (TDS) is one of the major challenges faced by the World Leather Industry. Conventional treatment system reduces Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), Suspended Solids (SS), heavy metals etc. and not the TDS and salinity. To achieve the TDS level, the tanneries in South India were forced to adopt Zero Liquid Discharge (ZLD) system by incorporating Reverse Osmosis (RO) system and Multiple Effect Evaporator (MEE). Though recovery of water is beneficial to certain extend in adopting ZLD system, the major challenges are high energy consumption, huge operation & maintenance cost and no safe disposal method for large quantity of mixed/contaminated salt generated from MEE. In view of the challenges faced in adoption of ZLD system, sustainable major technological developments have been made to control more than 50% of TDS in the effluent by adopting cleaner tanning process, segregation of saline streams, treatment and recovery of chromium and salt for reuse by the member units. The balance composited waste stream with low TDS is further treated and taken for mixing/dilution with treated domestic sewage to achieve all discharge standards including TDS. This development is being implemented in many tannery clusters in India such as Pallavaram in South India and Jajmau, Unnao, Banthar, etc. in North India. The Common Effluent Treatment Plants (CETPs) are being upgraded with financial support from Govt. of India and respective State Governments. Take-Away: Improved Chrome Recovery System for Reuse, Recovery of Salt from Saline Stream and Reuse, Sustainable TDS Management

Thesis (Masters of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, [2018].
Enhancing the efficiency of large scale photocatalytic systems has been a concern for decades. Engineering design and modelling for the successful application of laboratory-scale techniques to large scale is obligatory. Among the many fields of research in heterogeneous photocatalysis, photocatalytic reaction engineering can initiate improvement and application of conservative equations for the design and scale-up of photocatalytic reactors. Various reactor configurations were considered, and the geometry of choice was the annular shape. Theory supports the view that annular geometry, in the presence of constant transport flow properties, monochromatic light, and an incompressible flow, will allow a system to respect the law of conservation of mass. The degradation of a simulated dye, methyl orange (MO), by titanium dioxide (TiO2) with a simulated solar light (halogen lamp) in a continuous recirculating batch photoreactor (CRBPR) was studied. A response surface methodology (RSM) based on central composite design (CCD) was applied to study interaction terms and individual terms and the role they play in the photocatalytic degradation of MO. The studied terms were volume (L), TiO2 (g), 2 (mL), and initial dye concentration (mg/L), to optimize these parameters and to obtain their mutual interaction during a photocatalytic process, a 24 full-factorial CCD and RSM with an alpha set to 1.5 were employed. The polynomial models obtained for the chosen responses (% degradation and reaction rate constant, k) were shown to have a good externally studentized vs normal percentage probability fit with R2 values of 0.69 and 0.77 respectively. The two responses had a common significant interaction term which was the H2O2 initial dye concentration term. The optimum degradation that was obtained in this study was a volume of 20 L, TiO2 of 10 g, H2O2 of 200 mL and the initial dye concentration of 5 mg/L which yielded 64.6% and a reaction rate constant of 0.0020 min-1. The model of percentage degradation was validated on a yield of 50% and 80% over a series of set volumes and the model validation was successful.

Thesis (MSc)--Stellenbosch University, 2000.
ENGLISH ABSTRACT: A severely polluted industrial effluent is generated by the local gelatinmanufacturing industry. Due to increasingly stringent restrictions on discharge qualities enforced by the National Water Act of 1998 and National Environmental Management Act of 1998, as well as increasing trade-effluent charges implemented via the Local Municipal Bylaws, the industry is compelled to consider a system to pre-treat the polluted effluent. A study was undertaken to examine the viability of anaerobic treatment of the gelatin-manufacturing effluent, since the anaerobic digestion technology is well recognised for the high success rate in the treatment of high-strength, complex wastewaters. Various laboratory and pilot-scale studies were done, using different hybrid Upflow Anaerobic Sludge Blanket (UASB) and contact designs. Two mesophilic laboratory-scale hybrid UASB digester designs, fitted with polyethylene (AD-1) and polyurethane (AD-2), performed well at a hydraulic retention time (HRT) of 1.0 d. Chemical oxygen demand (COD) removal efficiencies of up to 90% (avg. 53%) for AD-1 and 83% (avg. 60%) for AD-2 at organic loading rates (OLR) of 9.56 and 4.62 kg COD.m-3.d-1, respectively, were obtained. High sulphate (S04) removal efficiencies of up to 96% (avg. 86%) for AD-1 and 98% (avg. 82%) for AD-2 were also achieved, respectively. A maximum total solid (TS) removal of 65% (avg. 25%) for AD-1 and 62% (avg. 28%) for AD-2 was reported. An average methane content of 80% (AD-1) and 79% (AD-2) with average methane yields per COD removed of 2.19 and 1.86 m3. kg CODremoved.df-o1r AD-1 and AD-2 were found, respectively. When the same digesters (AD-1 and AD-2) were combined in a muItiphase series configuration, a total COD removal efficiency of up to 97% (avg. 80%) at an OLR of 8.32 kg COD.m-3.d-1,was achieved. Excellent total S04 removals of 96% (avg. 69%) were accomplished. Up to 82% TS (avg. 29%) was also removed during this study and the biogas consisted of 89% methane (avg. 79%). For this multi-phase combination up to 92% volatile fatty acids (VFA) (avg. 48%) were removed, indicating possible selective phase separation of the respective fatty acid producing/utilising bacterial populations. The use of a laboratory-scale UASB bioreactor with recirculation, resulted in COD removal efficiencies of up to 96% (avg. 51%) at an HRT of 3.0 d, and 95% (avg. 54%) at a HRT of 1.0 d. Low performances were generally found, with average S04 and TS removals of 59% (max. 97%) and 26% (max. 67%), respectively at an HRT of 1.0 d. The biogas production was very low throughout the study (0.05 - 0.63 I,d-1 ). A pilot-scale UASB reactor (300 I) was constructed and performed satisfactory with a 58% average COD removal and maximum of 96%. S04 and TS removals up to 96% (avg. 44%) and 93% (avg. 63%), respectively, were obtained. The methane content of the biogas was 85%. The pilot-scale studies were conducted under actual field conditions, where various shock and organic loads had to be absorbed by the system. The pilot-scale contact configuration (300 I) did not perform satisfactory as a result of continuous blockages experienced in the feed and recirculation lines. Maximum COD, S04, VFA and TS removal efficiencies of 41% (avg. 27%), 62% (avg. 41%), 64% (avg. 27%) and 39% (avg. 21%), respectively, were obtained. The results of all the studies indicated acceptable COD removals with increasing OLR's. Indications of the presence of active methanogenic and sulphate-reducing bacterial populations were apparent throughout the studies. One possibility for the successful start-up and commissioning of the anaerobic reactors was the use of a well-adjusted biomass, which consisted of highly selected and adapted microbial consortium for the specific gelatinmanufacturing effluent. It was clear from this study that gelatin-manufacturing effluent can be treated successfully, especially with the use of the UASB design. A welldefined data base was constructed which could be of great value for further upscaling to a full-scale digester.
AFRIKAANSE OPSOMMING: 'n Hoogs besoedelde industriele uitvloeisel word gegenereer deur die plaaslike gelatien-vervaardigings industrie. As gevolg van toenemende streng beperkings op die kwaliteit van uitvloeisels wat bepaal word deur die Nasionale Water Wet van 1998 en Nasionale Omgewings Bestuurs Wet van 1998, asook toenemende munisipale heffings wat geimplementeer word via Plaaslike Munisipale Wette, word die industrie verplig om die uitvloeisel vooraf te behandel. 'n Studie is onderneem om die lewensvatbaarheid van anaërobe behandeling van gelatien-vervaardigings uitvloeisel te ondersoek, aangesien anaërobe verterings tegnologie alombekend is vir die goeie sukses behaal in die behandeling van hoë-sterkte, komplekse uitvloeisels. Verskeie laboratorium- en loods-skaal studies is gedoen, met verskillende hibried Opvloei Anaërobe Slykkombers (OAS) en kontak ontwerpe. Goeie werksverrigting was verkry by 'n hidroliese retensie tyd (HRT) van 1.0 d met twee mesofiliese laboratorium-skaal hibried OAS verteerder ontwerpe wat uitgevoer was met poli-etileen (AD-1) en poli-uretaan (AD-2) materiaal. Chemiese suurstof behoefte (CSB) verwyderings van so hoog as 90% (gem. 53%) vir AD-1 en 83% (gem. 60%) vir AD-2 by organiese ladingstempo's (OLT) van 9.56 en 4.62 kg CSB.m-3.d-1,was onderskeidelik verkry. Hoë sulfaat (S04) verwyderings van tot 96% (gem. 86%) vir AD-1 en 98% (gem. 82%) vir AD-2 was ook onderskeidelik verkry. 'n Maksimum totale vaste stof (TVS) verwydering van 65% (gem. 25%) vir AD-1 en 62% (gem. 28%) vir AD-2 is gerapporteer. 'n Gemiddelde metaan inhoud van 80% (AD-1) en 79% (AD-2) met 'n gemiddelde metaan opbrengs per CSB verwyder van 2.19 en 1.86 m3.kg CSBverwyder.dv-i1r AD-1 en AD-2, was onderskeidelik gevind. Met die aanwending van dieselfde twee verteerders (AD-1 en AD-2) in 'n series gekoppelde multi-fase konfigurasie, is 'n totale CSB verwydering so hoog as 97% (gem. 80%) verkry by 'n OLT van 8.32 kg CSB.m-3.d-1. Uitstekende totale S04 verwydering van 96% (gem. 69%) is behaal. Tot 82% TVS (gem. 29%) was vewyder gedurende die studie en die biogas het uit 89% metaan (gem. 79%) bestaan. Vir die multi-fase kombinasie is 'n maksimum van 92% vlugtige vetsure (WS) (gem. 48%) verwyder, wat dui op die moontlike skeiding van selektiewe fases van die onderskeie vetsuur produserende/verbruiker bakteriële populasies. CSB verwydering van tot 96% (gem. 51%) by 'n HRT van 3.0 d en 95% (gem. 54%) met 'n HRT van 1.0 d was verkry, tydens die gebruik van In laboratorium-skaal OAS bioreaktor met hersirkulasie. Lae werksverrigting was oor die algemeen waargeneem, met gemiddelde S04 en TVS verwyderings van 59% (maks. 97%) en 26% (maks. 67%) by In HRT van 1.0 d. Die biogas produksie was baie laag gedurende die studie (0.05 - 0.63 I,d-\ In Loods-skaal OAS verteerder was opgerig en bevredigende resultate was verkry met In gemiddeld van 58% CSB verwydering en maksimum van 96%. S04 en TVS verwyderings so hoog as 96% (gem. 44%) en 93% (gem. 63%) is onderskeidelik verkry. Die metaan inhoud van die biogas was 85%. Die loods-skaal studie was uitgevoer gedurende ware veld kondisies, waartydens verskeie skok en organiese ladings deur die sisteem geabsorbeer is. Die loods-skaal kontak konfigurasie (300 I) het nie bevredigende resultate getoon nie, as gevolg van voortdurende blokkasies wat ondervind is in die toevoer en hersirkulasie pype. Maksimum CSB, S04, WS en TVS verwyderings van 41% (gem. 27%), 62% (gem. 41%), 64% (gem. 27%) en 39% (gem. 21%) was onderskeidelik verkry. Die resultate van al die studies het aanvaarbare CSB verwydering aangedui by toenemende OLT's. Indikasies van aktiewe metanogene en sulfaat-reduserende bakteriële populasies was ook teenwoordig gedurende die studies. Die suksesvolle aansit-prosedure en begin van die anaërobe verteerders kan toegeskryf word aan die gebruik van In goed aangepaste biomassa, wat uit hoogs selektiewe en aangepaste mikrobiese populasies vir die spesifieke uitvloeisel bestaan. Hierdie studie het getoon dat gelatien-vervaardigings uitvloeisel suksesvol met die OAS ontwerp behandel kan word. In Goed gedefinieerde data basis kan voorsien word, wat van groot waarde sal wees vir verdere opgradering na In volskaalse verteerder.

The feasibility of using hydrochloric acid (HCl), heat, dilution and magnetic stirring for the pre-treatment of palm oil mill Effluent (POME) before the primary anaerobic treatment was investigated in this study. The theoretical background of oily water emulsion which is the characteristic of POME was reviewed. A range of experiments was performed on samples made up of different combinations of the three major components of POME namely, palm oil, solid from decanter and water. The results suggest that the development of a pre-treatment system to remove the 0.5- 1.2% residue oil and 3-4% solid matter from the fresh POME is feasible thus it could improve the efficiency of further downstream POME treatment.Experiments were conducted to examine the rate of oil flotation from the mixtures of different ratios of palm oil and water treated with different concentrations of HCl, and temperatures and magnetic stirring. Similarly, a series of experiments were performed to determine the rate of solid settlement from palm oil-solid mixture, solid-water mixture and palm oil-solid-water mixture of different ratios treated with different concentrations of HCl and different temperatures. The data obtained from the experiments were used to determine the optimum dosage of HCl used and the temperature required for best oil recovery and solid settlement.From the kinetic studies, the models of the kinetic rate of palm oil flotation and solid settlement were derived. A macro kinetic modeling was adapted to the oil flotation while a power model was used for solid settling. The results showed that treatment with 0.5% HCl was sufficient to increase the rate of oil flotation significantly in Palm oil-water mixture. However, the effect was dependent on the oil-water ratio. An increase in temperature gave higher rate of oil flotation but not as great as that of HCl treatment. Dilution was found to be the two other factors that affected the rate of flotation. The solid settling rates in all tested samples were not significantly affected when they were treated with HCl. The rate of solid settlement was found to be temperature dependent. The optimum temperature for the rate of solid sedimentation was found to be in the region of 800C. Similar positive effect was also observed for a more diluted sample of Solid-Palm oil-Water mixture.

The sponsored bench-top scale Monoethylene glycol distillation unit located at Curtin University was designed and operated to use realistic production fluids, such as condensate mixtures and formation water/brines to simulate conditions representative industrial MEG systems. Many parameters such as MEG inlet concentration, temperature, rebiler temperature, inlet mass flowrate and reflux ratio have been experimentally examined to achieve the optimum conditions for the distillation process. These results were then compared with the results from HYSYS simulation.

The low-rate trickling filter is the most common biological treatment process used in small and medium sized sewage works in the UK. It produces an inconsistent effluent quality, which has traditionally been related to seasonal changes in solids accumulation, grazing activity and sloughing of microbial film. The final effluent solids and, organic matter content is then too high for discharge or reuse. Given the increasingly stringent effluent standards, both in terms of quality and consistency, tertiary treatment is often required. This study was designed to investigate the key parameters affecting the performance of low-rate trickling filters and the characteristics of their effluents in terms of contaminant size, which might influence the efficiency of crossflow filtration as a tertiary treatment for the trickling filter.

The research project was formulated to solve serious environmental and possible public health problems in rural and regional areas caused by the common failure of soil disposal systems used for application of effluent from on-site domestic sewage treatment systems. On-site sewage treatment systems adopt a treatment train approach with the associated soil disposal area playing a crucial role. The most common on-site sewage treatment system that is used is the conventional septic tank and subsurface effluent disposal system. The subsurface effluent disposal area is given high priority by regulatory authorities due to the significant environmental and public health impacts that can result from their failure. There is generally very poor householder maintenance of the treatment system and this is compounded by the failure of the effluent disposal area resulting in unacceptable surface and groundwater contamination. This underlies the vital importance of employing reliable science-based site suitability assessment techniques for effluent disposal. The research undertaken investigated the role of soil physico-chemical characteristics influencing the behaviour of effluent disposal areas. The study was conducted within the Logan City Council area, Queensland State, Australia. About 50% of the Logan region is unsewered and the common type of on-site sewage treatment used is a septic tank with subsurface effluent disposal area. The work undertaken consisted of extensive field investigations, soil sampling and testing, laboratory studies and extensive data analysis. In the field study, forty-eight sites were investigated for their effluent application suitability. The sites were evaluated based on the soil physico-chemical characteristics. The field investigation indicated that there were nine soil orders in the study area. These soil orders were Dermosols, Chromosols, Kandosols, Kurosols, Vertosols, Sodosols, Tenosols, Rudosols and Anthrosols. The soils in all the investigated sites were acidic soils in the pH range between 5 and 6.5. The complexity of the large data matrix obtained from the analysis was overcome by multivariate analytical methods to assist in evaluating the soils' ability to treat effluent and to understand the importance of various parameters. The analytical methods selected to serve this purpose were PROMETHEE and GAIA. The analysis indicated that the most suitable soils for effluent renovation are the Kandosols whilst the most unsatisfactory soil order was found to be Podosol. The GAIA analysis was in agreement with quantitative analysis conducted earlier. An extensive laboratory column study lasting almost one year was undertaken to validate the results of the data analysis from the field investigation. The main objectives of this experiment were to examine the soil behaviour under practical effluent application and to investigate the long-term acceptance rate for these soils. Twelve representative soils were selected for the column experiment from the previously investigated sites and undisturbed soil cores were collected for this purpose. The results from the column study matched closely with the evaluation conducted at the earlier stages of the research. Soil physico-chemical analysis before and after effluent application indicated that the soils' acidity was improved toward neutrality after effluent application. The results indicated that soils have a greater ability to handle phosphorus than nitrogen. The most favorable cation exchange capacity for soils to treat and transmit effluent was between 15 and 40 meq/100g. Based on the results of the column study, the long-term acceptance rate (LTAR) was determined for the investigated twelve soil types. Eleven out of twelve soils reported specific LTAR values between 0.18-0.22 cm/day. For the duration of the laboratory study, the Podosol order did not reach its LTAR value due to the extremely sandy nature of the soil. The time required to achieve LTAR varied between different soils from 40 to 330 days. The outcomes of this research was integrated into a soil suitability map for on-site sewage treatment systems for Logan City Council. This will assist the authorities in providing sustainable solutions for on-site systems failure.

En este trabajo se aplican diferentes estrategias de control en las plantas de tratamiento de aguas residuales. El primer objetivo es la mejora del rendimiento de control. Básicamente, esto sirve como una prueba de que la estrategia de control propuesta se ha aplicado correctamente. El objetivo final es el efecto de la estrategia de control aplicada sobre el rendimiento de la planta. En concreto, mejorar la calidad del efluente, reducir costes de operación y evitar violaciones de los límites establecidos en el efluente. La evaluación de las diferentes estrategias de control se lleva a cabo en primer lugar con el Benchmark Simulation Model No. 1 (BSM1), y en segundo lugar con Benchmark Simulation Model No. 2 (BSM2). BSM1 se centra en el tratamiento biológico mediante reactores de lodos activos, y la evaluación se basa en una semana de simulación. BSM2 es una versión extendida del BSM1, agregando el tratamiento de lodos y proporciona un afluente más elaborado y variable, con un año de evaluación. Los enfoques de control se basan en Control Predictivo basado en Modelo, control difuso, funciones que relacionan las variables de entrada y las manipuladas, y Redes Neuronales Artificiales. El Control Predictivo basado en Modelo se propone para una mejora del tracking. El control difuso y las funciones se implementan para mejorar los procesos de desnitrificación o de nitrificación en base a los objetivos propuestos. Sus parámetros de sintonía se seleccionan mediante análisis trade-off. Las Redes Neuronales Artificiales se aplican para detectar riesgo de violaciones y obtener una selección automática de la estrategia de control adecuada. Se muestran los resultados y se comparan con las estrategias de control por defecto y con la literatura. Para el rendimiento de control, se obtiene una mejora satisfactoria. En cuanto al rendimiento de la planta, en la mayoría de los casos se evitan violaciones de los límites establecidos de nitrógeno total y de amonio y nitrógeno amoniacal, mientras que también se consigue una mejora de la calidad del efluente y una reducción de costes de operación.
In this work different control strategies are applied in wastewater treatment plants. The first objective is the control performance improvement. Basically, this serves as a proof that the proposed control strategy has been applied properly. The final objective is the effect of the applied control strategy on the plant performance. Specifically, the effluent quality improvement, costs reduction and avoiding violations of the established effluent limits. The evaluation of the different control strategies is carried out first with Benchmark Simulation Model No. 1 (BSM1), and secondly with Benchmark Simulation Model No. 2 (BSM2). BSM1 is focused on the biological wastewater treatment by activated sludge reactors, and the evaluation is based on a week of simulation. BSM2 is extended adding the sludge treatment and provides a more elaborated and variable influent with an assessment of one year. The control approaches are based on Model Predictive Control, Fuzzy Control, functions that relate the input and manipulated variables and Artificial Neural Networks. Model Predictive Control is proposed for tracking improvement, Fuzzy Controllers and functions are implemented to improve the denitrification or nitrification processes based on the proposed objectives. Their tuning parameters are selected by trade-off analyses. Artificial Neural Networks are applied to detect risk of violations for an automatic selection of the suitable control strategy. The results are presented and compared with the default control strategy and with the literature. For the control performance, a satisfactory improvement is obtained. Regarding the plant performance, in most of the cases, violations of the established limits of total nitrogen and ammonium and ammonia nitrogen are avoided, as well as an effluent quality improvement and cost reduction are achieved.

Soil aquifer treatment (SAT) for filtered primary effluent was simulated using two 1-m plexiglass columns (7 .62 cm i.d.) packed with sandy loam soil. When 0 2 was available, the organic levels achieved (mean DOC: 5.5 mg/1, mean UV A254: 0.1 cm-1) in the renovated water were not significantly different from those obtained when secondary eflluents are used. The combination of aerobic processes coupled with sorption and filtration were responsible for the removal of particulate (mean turbidity: 0.77 N.T.U.) and dissolved organic matter. Continuous 0 2 availability tended to block denitrification reactions causing nitrification to control the fate and transport of nitrogen species. The denitrification potential of filtered primary effluent, reflected in 32-57% overall nitrogen removals, was confirmed by nitrate effluent spiking and oxygen limited conditions with the decrease in organics removals. Relatively little phosphorus was retained through one-meter depth of soil during SAT. Significant removals on total (3-5 log units) and fecal (close and below detection limits) coliforms were achieved under continuous 0 2 availability. Coliphage removal efficiency, however, was less (