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Blecken, Godecke-Tobias. "Biofiltration technologies for stormwater quality treatment." Doctoral thesis, Luleå tekniska universitet, Arkitektur och vatten, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-18090.
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Due to high runoff volumes and peak flows, and significant contamination with (inter alia) sediment, metals, nutrients, polycyclic aromatic hydrocarbons and salt, urban stormwater is a major cause of degradation of urban water ways. Since current urban drainage systems, which heavily rely on piped sewer networks, may not be sustainable, attempts are being made to develop and refine sustainable urban drainage solutions, notably in Water Sensitive Urban Design (WSUD) and Low Impact Development (LID) concepts. Promising systems recommended for application in both WSUD and LID are stormwater biofilters (also known as bioretention systems or rain gardens) using vegetated filter media. Besides their capacity to attenuate flows and minimise runoff volumes, stormwater biofilters have proven efficacy for enhancing effluent water quality. Furthermore, they can be aesthetically pleasingly integrated even in dense urban environments. However, there are still gaps in our knowledge of the variability of biofilters' pollutant removal performance, and the factors that affect their performance.In the studies this thesis is based upon, the effects of various ambient factors, stormwater characteristics and modifications of filter design on the removal of metals, nutrients and total suspended solids (TSS) in biofilters, and pollutant pathways through them, have been investigated. For these purposes, standard biofilters and variants equipped with a submerged zone, a carbon source and different filter materials were exposed to varying temperatures and dry periods, dosed with stormwater and snowmelt, and the inflow and outflow concentrations of the pollutants were measured.Although removal percentages were consistently high (>70%), demonstrating that biofilters can reliably treat stormwater, the results show that metal outflow concentrations may vary widely depending on the biofilter design and the ambient conditions. Prolonged drying especially impaired their removal efficiency, but variations in temperature and filter media variations had little effect on metal removal rates. The adverse effects of drying could be mitigated by using a submerged zone, and thus providing a more constant moisture regime in the filters between storm events. Combined with embedded organic matter, the submerged zone especially significantly enhances Cu removal, helping to meet outflow target concentrations. Similarly, installing a mulch layer on top of the filter provides additional sorption capacity, hence metals do not ingress far into the filter and are mainly trapped on/in the top layer by sorption processes and/or mechanical trapping associated with TSS. This leads to significant metal accumulation, which facilitates biofilter maintenance since scraping off the top layer removes high proportions of previously accumulated metals, thus delaying the need to replace the whole filter media. However, removal of accumulated pollutants from the filter media is crucial for successful long-term performance of the filters to ensure that no pollutant breakthrough occurs.Nitrogen removal was found to be more variable than metal removal, and to be adversely affected by temperature increases, leading to high nitrogen leaching in warm temperatures. Phosphorus removal rates were consistently high, since most phosphorus was particle-bound and thus trapped together with TSS. However, in initial stages phosphorus was washed out from the filter media, indicating that filter media that do not have high levels of labile phosphorus should be used to avoid high effluent concentrations. Given that most outflow concentrations were far lower than those in the stormwater, biofilters are appropriate stormwater treatment systems. Dependent on the ambient conditions, the target pollutants and the sensitivity of the recipient, adaptation of the filter design is recommended. Further work is required to investigate the winter performance and improve the reliability of nitrogen removal, which is highly variable.<br>Dagvatten är en viktig orsak till ekologiska försämringar av urbana vattendrag p.g.a. stora avrinningsvolymer, och höga flöden samt en tillförsel av diverse föroreningar, t.ex. sediment, tungmetaller, näringsämnen, polycykliska aromatiska kolväten och salt. Dagvattenhanteringen har länge varit fokuserad enbart på att leda bort vattnet i rörledningar utan att hänsyn har tagits till retention av stora flöden eller till vattenkvalitén. På grund av dessa problem har utvecklingen av uthålliga dagvattensystem blivit allt viktigare och koncept som Lokalt Omhändertagande av Dagvatten (LOD), Water Sensitive Urban Design (WSUD) och Low Impact Development (LID) har utvecklats. En uthållig lösning inom dessa koncept är dagvattenbiofiltrering.Dagvattenbiofilter är infiltrationsbäddar med växter där dagvattnet infiltrerar och renas av växterna och filtermaterialet. De har en god förmåga att fördröja stora flöden samt att reducera föroreningar i dagvattnet innan det släpps ut till recipienten. Dessutom är det en estetisk och naturnära teknik som mycket väl kan integreras arkitektoniskt i både nya och befintliga stadsmiljöer. Dock saknas det fortfarande mycket kunskap om de processer som styr reningsförmågan samt hur de påverkas av varierande omgivningsförhållanden. I denna avhandling har därför effekterna av olika omgivningsfaktorer, dagvattenegenskaper och design av biofilter på reningen av metaller, näringsämnen och sediment undersökts. För att undersöka detta har biofilter, som delvis försetts med olika filtermaterial eller en vattenmättad zon, till dels kombinerad med en kolkälla, och utsatts för olika temperaturer och torra perioder. Biofiltren har bevattnats med dagvatten eller smältvatten. Prover har tagits på ingående och utgående vatten och föroreningskoncentrationerna har analyserats. Trots att reduktionsförmågan av metaller var hög (>70%), vilket bekräftar att biofiltren har förmågan att effektivt rena dagvattnet, visar resultaten att de utgående metallkoncentrationerna kan variera mycket beroende på utformningen av biofilter och varierande omgivningsfaktorer. Torra perioder som är längre än 3 till 4 veckor minskar metallavskiljningen i biofilter, medan växlande temperaturer och olika filtermaterial hade mindre betydelse för metallreningen. Dock kan en vattenmättad zon i filtermaterialet minimera (Cu och Zn) eller till och med avlägsna (Pb) den negativa effekten av torka med avseende på reningsförmågan. I kombination med en kolkälla kan en vattenmättad zon öka reningseffekten för framför allt Cu (som inte är lika bra i standardutförande av biofilter) på grund av en ökad komplexbildning och partikulärt organiskt material. Sediment, metaller och partikelbundna dagvattenföroreningar hålls tillbaka redan i det översta filterlagret vilket leder till en hög metallackumulation. Detta underlättar filterunderhållet: genom att skrapa och ersätta bara det översta jordlagret kan en hög andel ackumulerade föroreningar tas bort från filtret. Således kan utbyte av det hela filtermaterialet fördröjas.Kvävereningen var inte lika effektiv som metallreningen. I varma temperaturer (20°C) har kväveutlakning i stället for reduktion observerats. Fosforreningen var dock hög eftersom fosfor var mestadels partikelbunden och blev därför filtrerat tillsammans med sedimentet i det översta filterlagret. I början av biofilterdriften har dock fosforurlakning från filtermaterialet observerats vilket tyder på att det inte ska innehåller höga halter av fosfor för att undvika utlakning från filtret. Eftersom de flesta föroreningskoncentrationer i det utgående vattnet var betydligt lägre än i dagvattnet är biofilter en uthållig och tillförlitlig teknik för dagvattenrening. Beroende på olika omgivningsfaktorer samt de ekologiska förhållandena i recipienten rekommenderas dock anpassning av filterdesignen. Framtida forskning behövs för att undersöka biofiltrens reningsförmåga under vinterförhållanden och för att förbättra den varierande kvävereningen.<br>Godkänd; 2010; 20100812 (godble); DISPUTATION Ämnesområde: VA-teknik/Sanitary Engineering Opponent: Professor Jean-Luc Bertrand-Krajewski, INSA de Lyon, Frankrike Ordförande: Professor Maria Wiklander, Luleå tekniska universitet Tid: Fredag den 8 oktober 2010, kl 10.00 Plats: F1031, Luleå tekniska universitet
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Cutbill, Linda Beverley. "Urban stormwater treatment by artificial wetlands." Thesis, University College London (University of London), 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.266138.
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Wang, Chih-Yu. "Floating wetlands for urban stormwater treatment." Diss., Virginia Tech, 2013. http://hdl.handle.net/10919/52036.
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A floating treatment wetland (FTW) is an ecological approach which seeks to reduce point and nonpoint source pollution by installing substrate rooted plants grown on floating mats in open waters. While relatively novel, FTW use is increasing. A review of literature identified several research gaps, including: (1) assessments of the treatment performance of FTWs; (2) evaluations of FTWs in the U.S., particularly within wet ponds that receive urban runoff; and (3) plant temporal nutrient distribution, plant growth rate, and the long-term persistence of the FTWs in temperate regions with periodic ice encasement.
An assessment model, i-FTW model, was developed, and its parameter s fitted based on data from 14 published FTW studies in the first research topic. The estimated median FTW apparent uptake velocity with 95% confidence interval were 0.048 (0.018 - 0.059) and 0.027 (0.016 - 0.040) m/day for total phosphorus (TP) and total nitrogen (TN), respectively. The i-FTW model provided a more accurate prediction in nutrient removal than two common performance metrics: removal rate (mg/m2/day) and removal efficiency (%). In the second research topic, the results of a mesocosm experiment indicated that FTWs with 61% coverage, planted with pickerelweed (Pontederia cordata L.) or softstem bulrush (Schoenoplectus tabernaemontani), significantly improved TP and TN removal efficiency of the control treatment by 8.2% and 18.2%, respectively. The pickerelweed exhibited significantly higher phosphorus and nitrogen removal than the softstem bulrush when water temperatures were greater than 25 deg C. Field observations in the third research topic found that pickerelweed demonstrated higher phosphorus removal performance (7.58 mg/plant) than softstem bulrush (1.62 mg/plant). Based on the observed seasonal changes in phosphorus distribution, harvest of above-ground vegetation is recommended to be conducted twice a year in June and September. Planted perennial macrophytes successfully adapted to stresses of the low dissolved oxygen (DO) concentrations (minimum: 1.2 mg/L), ice encasement, and relatively low nutrient concentrations in the water (median: 0.15 mg/L TP and 1.15 mg/L TN). Systematic observation of wildlife activities indicated eight classes of organisms inhabiting, foraging, breeding, nursing, or resting in the FTWs. Recommendations for FTW design and suggestions for further research are made based upon these findings.<br>Ph. D.
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Regent, Yoann. "Urban stormwater management: : Optimization of the treatment of stormwater in urban areas." Thesis, KTH, Industriell ekologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-58645.
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The Mulden-Rigolen system, a new urban stormwater management system implemented in Germany, has been examined in this study. The aim of this new system is to replace traditional sewer system for urban road runoff, by infiltrating the incoming water locally through a dual underground system: an active top soil layer and a deeper trench of packed gravel. For each site using this system, the characteristics of the soils in terms of pH, texture, organic matter, infiltration rate as well as Heavy Metals (Cd, Cr, Cu, Pb, Zn) and Phosphorus soil concentrations were successfully determined. The measured values for the soil characteristics were still, after an operation time of up to 15 years for some sites, globally in the range of the recommendation of the German Association for Water, Wastewater and Waste, except for organic matter in some sites, suggesting the need for a more cautious maintenance. Concerning heavy metals and phosphorus content, no alarming soil contamination was observed indicating that the studied “Mulden-Rigolen” systems were still acceptable in terms of soil pollution after several years of use, according to the Danish standards. If this system seemed to have a good flexibility and adaptability to different urban land uses, its treatment efficiency still has to be fully assessed. Indeed, only a primary evaluation of its performance war carried out through a simplistic model which brought up some questions about pollutant retention (especially in case of Zn). Further research (intact soil columns experiments, sequential extractions, on-site runoff sampling) would be necessary to fully determine how well this system works in terms of water treatment.
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DeBusk, Kathy Marie. "Stormwater Treatment by Two Retrofit Infiltration Practices." Thesis, Virginia Tech, 2008. http://hdl.handle.net/10919/32757.
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Increases in impervious surfaces associated with urbanization change stream
hydrology by increasing peak flow rates, storm-flow volumes and flood frequency, and
degrade water quality through increases in sediment, nutrient, and bacteria
concentrations. In response to water quality and quantity issues within the Stroubles
Creek watershed, the Town of Blacksburg and Virginia Tech designed and constructed
two innovative stormwater best management practices (BMPs). The goal of this project
was to evaluate the effectiveness of a bioretention cell and a CU-Structural Soilâ ¢
infiltration trench. BMP construction was completed in July 2007. Twenty-nine
precipitation events were monitored over a period of five months between October 2007
and March 2008. For each storm, inflow and outflow composite samples were collected
for each BMP and analyzed for suspended sediment, total nitrogen, total phosphorus,
fecal coliform bacteria and E-coli bacteria. The inflow and outflow concentrations and
loads, as well as total inflow and outflow volumes and peak flow rates, were then
compared to evaluate how well each BMP reduces stormwater flows, decrease peak
runoff rates and improves water quality of stormwater runoff. Results for the bioretention
cell indicate average reductions in stormwater quantity, sediment, total nitrogen, total
phosphorus and fecal coliform bacteria that exceeded 99% by mass. The CU-Structural
Soilâ ¢ infiltration trench produced reductions in stormwater quantity, total phosphorus
and sediment that averaged 60%, 45% and 51%, respectively. Preliminary bacteria
results indicated that both BMPs served as sources of E-coli, and the infiltration trench
served as a source of fecal coliform bacteria.<br>Master of Science
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Milovanovic, Ivan. "Components for area-efficient stormwater treatment systems." Licentiate thesis, Luleå tekniska universitet, Arkitektur och vatten, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-83877.
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Bayley, Mark. "Constructed Ponds for the Treatment of Urban Stormwater - Biotic Processes Influencing the Removal of Nitrogen, Phosphorus and Carbon." Thesis, Griffith University, 2007. http://hdl.handle.net/10072/367630.
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Stormwater ponds for the treatment of urban runoff are being increasingly used as ‘treatment’ technologies in the management of urban stormwater world wide. Although stormwater ponds have been proven to be effective at reducing the concentration of nutrients from urban stormwater, the exact processes leading to this reduction remains largely unknown and unquantified. With stormwater management fast becoming a managed and mitigated water quality issue, the importance of our understanding on how these ecosystem function increases. A stormwater pond system designed and built for the treatment of urban runoff in 2001 was used as the study site for the PhD investigation. The primary goal of the PhD study was to investigate and quantify biological processes leading to N, P, and C load reduction within the inlet and outlet ponds at the Bridgewater Creek Stormwater Treatment System (BWC System) in Brisbane, Southeast Queensland Australia. The BWC System consists of 6 interconnected ponds spanning a total surface area of 0.8 ha, and draining 198 ha catchment consisting almost entirely of residential, single lot development. The initial sedimentation basin (Pond 1) and the final polishing pond (Pond 6) of the BWC System were the focus of the investigation.
Based on rainfall runoff rates, 29.5% of the catchment feeding into the stormwater treatment pond system was classed as ‘directly connected impervious area’, with each storm event delivering a mean 18.3ML of urban runoff. Data showed that storm events generating greater than 9.89 mm of rainfall produced runoff volumes greater than the storage capacity of the BWC System, thus triggering the high flow bypass channel. During the study period (2003-2005), 56.9% of all generated stormwater bypassed the BWC System, attributed to the small size of the pond system compared to its catchment drainage area. Within Ponds 2-6 of the treatment system, stormwater was retained for up to 9 days. Nutrient load reduction within the pond system was calculated at 50%, and 16% for TN and DOC respectively, but TP loads increased by 30% within the pond system. The export of TP loads greater than input for the given events within the BWC System was attributed, in part, to sediment resuspension and transportation due to the lack of significant macrophyte stands to stabilize sediment within the system. Possibly a result of this, the BWC System rarely achieved TP water quality objectives, set by the Brisbane City Council, but TN, Org-N, NH4, NOx and PO4 objectives where achieved more than 40% of the time.m Using Principal Component Analysis, three factors where found to significantly influence the variability of water quality within the pond system on a temporal scale. That being, ‘storm events’, ‘phosphorus dynamics’, and/or ‘DIN dynamics’. These factors effectively describe the abiotic or biotic variables driving water quality within the ponds at any given point in time. Key physicochemical parameters driving water quality in the ponds included pH, redox potential and DO. Water quality was similar between pelagic and littoral zones of both ponds within the BWC System.
The phytoplankton community within the BWC System was characteristic of polluted freshwaters, dominated by mixotrophic green algae. Cyanobacteria blooms within the ponds was minimal, with one bloom of Anabaena spp. occurring in Apr-04. Phytoplankton production rates were indicative of eutrophic freshwater environments (0.6-20 gC m?² day?¹), with production limited by light. Bacterioplankton production far exceeded that of phytoplankton production (8-210 gC m?² day?¹) during all incubations, defining the pond system as net heterotrophic. These high rates of bacterioplankton production coupled with the phytoplankton production suggested that the mineralsation of gross particulate organic matter entering the system during stormevents may be providing the nutrients nessasary to fuel such high production rates. Within Pond 1, nutrient movement across the benthic/water column interface were calculated at 0.73, 0.37 and 0.47 mg m?² day?¹ for TN, TP and DOC. In Pond 6, there was a gross loss of nutrients from the water column to the sediment zone for TN and TP (0.24 and 0.03 mg m?² day?¹) but not for DOC (sediment to water movement, 0.17 mg m?² day?¹). As in Pond 6, if sunlight can penetrate the benthos and gross particulate matter is low, Benthic Macro Algae can inhabit the benthos and enhace nutrient loss from the water column. During the mesocosom experiments the Ceratophyllum/epiphyton complex exhausted ammonia concentrations within the incubation jars and reduced PO4-P to background concentrations. Attached epiphyton and phytoplankton community displayed similar characteristics in PO4-P concentration reduction from the water column, with biotic uptake within the incubation jars limited to 0.03 and 0.02 mg L?¹ day?¹ respectively (0.14 mg L?¹ day?¹ for Ceratophyllum/epiphyton complex). From these incubation experiments, the important role of submerged macrophyte communities in nutrient reduction from the water coloumn was proven.
The research presented in this thesis justifies the use of stormwater ponds for urban stormwater management. The ability of submerged macrophytes at enhancing nutrient removal from stormwater was demonstrated. Phytoplankton and Bacterioplankton production and associated inorganic N and P uptake within the pond system did not correspond to measured and calculated storm flow inputs, indicating a large ‘unmeasured source’ – assumed to be the input of large particulate organic matter into the system during storm events.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>Griffith School of Engineering<br>Full Text
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LeNoble, Jesisca. "Genomics tool for monitoring engineered stormwater treatment wetlands." Thesis, University of British Columbia, 2017. http://hdl.handle.net/2429/62123.
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The full abstract for this thesis is available in the body of the thesis, and will be available when the embargo expires.<br>Applied Science, Faculty of<br>Civil Engineering, Department of<br>Graduate
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Lange, Katharina. "Total and dissolved metal treatment in stormwater bioretention." Licentiate thesis, Luleå tekniska universitet, Arkitektur och vatten, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-78424.
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Fahlbeck, Carlsson Sofia. "Evaluation of a gross pollutant trap-biofilter stormwater treatment train : The Role Of Calcium Carbonate, Vegetation And Pre-Treatment Facility." Thesis, Luleå tekniska universitet, Arkitektur och vatten, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-85808.
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Development of cities, new buildings and other impervious surfaces entails increased stormwater flows, volumes and pollutant loads. Heavy metals, nutrients, sediments and salt are common pollutants in stormwater. The conventional way to managestormwater, which is by discharge to the receiving water body via asewage network, will not be sufficient for mitigating high flows, flood risks and pollution export. Thus,Low Impact Development (LID) stormwater facilities, such as stormwater biofilters, are built in an increasing rate in Swedenand worldwide.The main function of a stormwater biofilter is water quality treatment, which is achieved when stormwater percolates through a vegetated filter media. Sometimes a pre-treatment facility is installed before the biofilter to reduce thesedimentload on the biofilter and extend its life-length. However, there are knowledge gaps regarding pollutant removal in biofilters and the role of associated pre-treatment facilities. In this study the impact of a pre-treatmentfacility, calcium carbonateas amendment in the filter media and vegetation wasinvestigated regardingtreatment of heavy metals (Cd(cadmium),Cu(copper), Pb (lead)and Zn (zinc)), phosphorus and total suspended solids. To do this, influent and effluent stormwater samples from an existing biofilter in Sundsvall were analysed and evaluated regarding removal performance of the above-mentionedpollutants. In general, the stormwaterbiofilter facility (including pre-treatment) removed total metals well while the removal of the dissolved fraction showed higher variations. Influent concentrations of TP were always higher than effluentconcentrations. Leaching of phosphate repeatedly occurred from the filter sections.The mean removalof TSS was high (96.9%). CaCO3as amendmentin the filter material had a beneficial effect on the overall metal removal of the stormwater facility. Although leaching of phosphate occurred from all filter sections, the leaching was lowest from the section with CaCO3, indicating possible benefits of CaCO3as amendment. CaCO3 did not seem to affect the mean total phosphorusremoval significantly.Removal of total metals seemed to be improved by vegetation, but the removal of dissolved metals, total phosphorusand phosphate did not seem to be enhanced by vegetation. The filter section with vegetation and without CaCO3 amendment contributed with the highest effluent concentrations of total phosphorusand phosphate (leaching), considering that vegetation released more phosphate that it captured. The main treatment of the stormwater pollutants occurred within the biofilter and both positive and negative removal of all pollutants was observed by the pre-treatment facility. The result showed that the pre-treatment facility was most beneficial for removal of dissolved metals.<br>Utvecklingen av städer, nya byggnader och andra hårdgjorda ytor ökar både mängden dagvatten och föroreningshalterna. Vanligt förekommande föroreningar i dagvatten är tungmetaller, näringsämnen, sediment och salt.Det traditionella sättet att hantera dagvatten är genom avledning via avloppsnätet till närliggande recipient, men med den förändrade kvalitén och kvantitet på dagvatten blir kapaciteten i det befintliga ledningsnätet otillräckligtför de ökadeflödenaoch föroreningsinnehållet.Därför byggs bland annat dagvattenbiofilter, som är en typ av Low Impact Development (LID), i en ökande takt i Sverigeoch globalt. Huvudsyftet med dagvattenbiofilter är dagvattenrening, vilket uppnås när dagvattnet filtreras genom en filterbädd med växter. För att minska (sediment)belastningenoch förlänga livslängden på biofiltret kan ibland en förbehandlingsanläggning placeras i före biofiltret. Dock finns det fortfarande kunskapsluckor om reningspotentialen i biofilter och betydelsen av en förbehandlingsanläggning. I den här studien undersöktes betydelsen av en förbehandlingsanläggning, kalciumkarbonat som tillsatsi filter materialet och växter på biofiltret för reningen av tungmetaller (Cd (kadmium), Cu (koppar),Pb(bly)ochZn(zink)), fosfor och totalt suspenderat material. För att undersöka detta analyserades och utvärderades dagvattenprover på inkommande och utgående vattenfrån ett biofilter i Sundsvall, med avseende på reningsprestation av ovan nämnda föroreningar. Resultatet visade att biofiltret (med förbehandlingsanläggningen inkluderad), renade totala metaller bra medanreningen av lösta metaller varierade mer. Inkommande koncentrationer av totalfosforvar alltid högre än utgåendekoncentrationeroch fosfat lakades kontinuerligt ut från filtersektionerna. Den genomsnittliga reningen av TSS var hög (96,9%).CaCO3 som tillsats i filtermaterialet hade en positiv effekt på reningen av totala och lösta metaller i biofiltret. Fosfat lakades ut från alla filtersektioner,men urlakningen var lägst från filtersektionen med CaCO3, vilket tyder på möjliga positiva effekterdet som tillsats i filtermaterialet.CaCO3 verkade inte öka genomsnittliga reningen av totalfosfor signifikant. Vegetationenverkade öka reningen av totala metallermen inte reningen av lösta metaller, totalfosfor eller fosfat. Filtersektionen med vegetation men utan CaCO3genererade de högstautgående koncentrationernaav totalfosfor och fosfat (urlakning), vilket tyder på att vegetation avgav mer fosfor än den tog upp. Den dominerande reningenav dagvattenföroreningarnaskedde inuti biofiltret och både högre och lägre koncentrationer av samtliga föroreningar observerades efter förbehandlingsanläggningen.Resultatetvisade attförbehandlingsanläggningen var mest effektiv för reningen av lösta metaller.
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Caruso, Nicole Theresa. "Biofiltration enhancement for the treatment of highway stormwater runoff." Thesis, Georgia Institute of Technology, 2014. http://hdl.handle.net/1853/53111.
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Highway stormwater runoff contains a number of contaminants including nutrients and heavy metals that can be detrimental to the health of lakes, rivers, and streams. Biofiltration is a common stormwater treatment mechanism that can reduce nutrients and heavy metals through physical, chemical, and biological processes. Vegetation type has been shown to impact the removal of nutrients from stormwater runoff (Barrett et al. 2013; Read et al. 2008). The inclusion of a permanent saturated layer underneath the surface of a biofilter has been investigated to enhance denitrification and thus nitrogen removal (Kim et al. 2003; Zinger et al. 2007). Six Georgia native grasses as well as one turf grass have been tested in a column study along with a permanent saturated zone for biofiltration enhancement. Synthetic stormwater was used in this study. Two months of dosages with an average synthetic stormwater were monitored followed by one event with a heavy metal spiked synthetic stormwater, one event with a nutrient spiked synthetic stormwater, and one event with an average synthetic stormwater after two weeks of drought conditions. Biomass fly ash was also added to columns to determine potential benefits to biofiltration applications.
Results indicated that Big Bluestem, Indiangrass, and Switchgrass when paired with a permanent saturated zone remove the highest percentage of total nitrogen across all experiments (4%, 13%, and 18% respectively). These species contained think and dense root systems that spanned the entirety of the biofilter column. Removal of nitrate was enhanced with a saturated zone while ammonium removal decreased. Nitrogen leaching from the columns may be reduced by utilizing soil of low organic content. Phosphorus, copper, lead, and zinc removal was not correlated with plant species; however, a permanent saturated zone increased removal of phosphorus, copper, and zinc (removal of lead was >97% in all cases making differences in removal insignificant).
These results support the impact of specific vegetation types on the removal extent of total nitrogen. Saturation provided benefits of total nitrogen, phosphorus, copper, and zinc removal in terms of removal extents as well as consistency of treatment across all experiments. Field experimentation is encouraged to determine long term effects at a large scale.
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Hodges, Clayton Christopher. "Optimization of BMP Selection for Distributed Stormwater Treatment Networks." Diss., Virginia Tech, 2016. http://hdl.handle.net/10919/81698.
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Current site scale stormwater management designs typically include multiple distributed stormwater best management practices (BMPs), necessary to meet regulatory objectives for nutrient removal and groundwater recharge. Selection of the appropriate BMPs for a particular site requires consideration of contributing drainage area characteristics, such as soil type, area, and land cover. Other physical constraints such as karst topography, areas of highly concentrated pollutant runoff, etc. as well as economics, such as installation and operation and maintenance cost must be considered. Due to these multiple competing selection criteria and regulatory requirements, selection of optimal configurations of BMPs by manual iteration using conventional design tools is not tenable, and the resulting sub-optimal solutions are often biased. This dissertation addresses the need for an objective BMP selection optimization tool through definition of an objective function, selection of an optimization algorithm based on defined selection criteria, development of cost functions related to installation cost and operation and maintenance cost, and ultimately creation and evaluation of a new software tool that enables multi-objective user weighted selection of optimal BMP configurations.
A software tool is developed using the nutrient and pollutant removal logic found in the Virginia Runoff Reduction Method (VRRM) spreadsheets. The resulting tool is tested by a group of stormwater professionals from the Commonwealth of Virginia for two case studies. Responses from case study participants indicate that use of the tool has a significant impact on the current engineering design process for selection of stormwater BMPs. They further indicate that resulting selection of stormwater BMPs through use of the optimization tool is more objective than conventional methods of design, and allows designers to spend more time evaluating solutions, rather than attempting to meet regulatory objectives.<br>Ph. D.
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Harmayani, Kadek Diana. "Nutrient Adsorption onto Sawdust for the Treatment of Stormwater." Thesis, Curtin University, 2013. http://hdl.handle.net/20.500.11937/70496.
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In this study, the sawdust of radiata pine wood was chosen as an adsorption medium to remove nutrients from stormwater. A series of batch and column experiments was carried out and a mass transfer correlation was developed to investigate the capability of sawdust in removing dissolved nutrients. The results indicate that sawdust is a promising adsorbent medium for nutrient removal. The findings of this research may be useful in designing biofiltration/bioretention systems for treating stormwater.
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Romah, Saheeda Marie. "EVALUATION OF PROPRIETARY STORMWATER TREATMENT DEVICES IN FIELD AND LABORATORY CONDITIONS." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3037.
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Proper stormwater management acknowledges both water quantity and water quality. Historically, stormwater quantity and quality have been separately considered; runoff was routed as quickly as possible into the nearest body of water. Although this alleviates potential flooding concerns, water quality is often compromised. Common stormwater quality problems include gross pollutants, sediment, nutrients, and heavy metals. The chronic elevated presence of these pollutants is detrimental to the environment. As a result, the government has passed legislature to protect waterways. The passage of the National Pollution Discharge Elimination System (NPDES) permit requires that municipalities implement stormwater treatment techniques, known as Best Management Practices (BMPs). Unfortunately, the NPDES document suggests treatment to the maximum extent possible, a vague description at best. This thesis reports a two-part study that endeavors to evaluate three of these proprietary treatment units manufactured by Stormceptor, BaySaver Separation Systems, and Continuous Deflective Separator (CDS) Technologies, Inc. to determine their performances. Each manufacturer produces a separator system that physically removes contaminants through the use of hydrodynamic flow principles. Phase I of the study focuses on monitoring two Stormceptor units and a CDS device in field conditions, while the second phase of the study evaluates each of the three treatment systems under laboratory conditions. The data analyses from the field study show the importance of proper maintenance. Storm events monitored after sump material removal showed great improvement over storm events occurring some time after the sump material removal. Furthermore, the treatment devices show a greater ability to remove pollutants from smaller storm events when compared with larger storm events. It is suggested that large storms cause scour of sediment previously trapped within the sump of the devices. An increase in the total suspended solid and nutrient concentrations, which were higher than the influent concentrations, was observed in both the field and laboratory studies. This could be explained by the fact that organics trapped by the treatment system decompose over time, therefore producing nutrient-rich water in the sump of the devices with higher concentration than the subsequent storm events. Some results are close to the minimum detection limit of the parameters being tested and small differences between influent and effluent load exaggerate the percent load differences. Consequently, there is little statistical significance between influent and effluent data, thus the data are summarized utilizing two methods. The methods include graphical representation of concentration and percent load difference, a method that normalized storms based on event size. In addition, a mass balance of gross litter was performed during the laboratory study.<br>M.S.C.E.<br>Department of Civil and Environmental Engineering<br>Engineering and Computer Science<br>Civil Engineering
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Hardin, Michael. "THE EFFECTIVENESS OF A SPECIFICALLY DESIGNED GREEN ROOF STORMWATER TREATMENT SYSTEM IRRIGATED WITH RECYCLED STORMWATER RUNOFF TO." Master's thesis, University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3681.
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One of our greatest threats to surface-water quality is polluted stormwater runoff. In this research, investigated is the use of a green roof irrigated with recycled stormwater runoff to remove pollutants from stormwater runoff and reduce the volume of stormwater runoff leaving developed areas. The green roof properties of interest are the filtration and biological processes as well as the roof's ability to hold water and increase evapotranspiration, reducing the volume of stormwater runoff from the source. Because of the above mentioned reasons the experiment consists of a water quality analysis and a water budget done on several experimental chambers modeled after the green roof on the student union building at the University of Central Florida. The green roof chambers are used to study different types of growing media, different irrigation rates, and the addition of plants and how stormwater runoff quality and quantity is affected. There are also control chambers built to model the conventional roof on the student union building. The purpose of the control is to determine the effectiveness of the different media's filtration/adsorption processes and ability to hold water, in addition to identifying the benefits of adding a green roof to both water quality and the water budget. This research showed that a specifically designed green roof stormwater treatment system with a cistern is an effective way to reduce both the volume of and mass of pollutants of stormwater runoff. The year long water budget showed that this system can reduce the volume of stormwater runoff by almost 90%. The green roof model developed within this work showed similar results for the same conditions. Design curves produced by the model have also been presented for several different geographic regions in Florida. The green roof stormwater treatment system presented within this work was effective at reducing the mass of pollutants. However, the concentration of several of the examined pollutants in the effluent of the cistern was higher or equivalent to that of a control roof. Nitrate and ammonia were two that had a lower concentration than the control roof. The use of a pollution control growing media was also examined. The results of this study show that the Black & GoldTM growing media is effective at removing both ortho-phosphorus and total phosphorus. Isotherm analysis was also preformed to quantify the adsorption potential. Despite the promise of the Black & GoldTM growing media to remove phosphorus the plants did not grow as well as in the expanded clay growing media. It is suggested that the pollution control media be used as a layer under the growing media in order to get the benefits of both media.<br>M.S.Env.E.<br>Department of Civil and Environmental Engineering<br>Engineering and Computer Science<br>Environmental Engineering
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Mangangka, Isri Ronald. "Role of hydraulic factors in constructed wetland and bioretention basin treatment performance." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/63054/1/Isri%20Ronald_Mangangka_Thesis.pdf.
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This research project contributed to the in-depth understanding of the influence of hydrologic and hydraulic factors on the stormwater treatment performance of constructed wetlands and bioretention basins in the "real world". The project was based on the comprehensive monitoring of a Water Sensitive Urban Design treatment train in the field and underpinned by complex multivariate statistical analysis. The project outcomes revealed that the reduction in pollutant concentrations were consistent in the constructed wetland, but was highly variable in the bioretention basin to a range of influential factors. However, due to the significant amount retention within the filter media, all pollutant loadings were reduced in the bioretention basin.
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Lessard, Paul. "Operational water quality management : control of stormwater discharges." Thesis, Imperial College London, 1989. http://hdl.handle.net/10044/1/47538.
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Islam, Md Kamrul. "Nutrient removal from urban stormwater using floating treatment wetland system." Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4936.
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Despite the technology advancement, degradation of water quality due to stormwater continues to be a significant threat to the water and ecosystems due to the exponential growth of industries and agricultural enterprises that discharge stormwater. These anthropogenic activities are the sources of high nitrogen and phosphorus quantities in stormwater, which is responsible for eutrophication phenomena and deterioration of public health. Floating Treatment Wetlands (FTWs) are a potential solution to this problem. Both microcosm and mesocosm level studies were conducted for the effective removal of nutrients in stormwater wet detention ponds with different sorption media under varying nutrient concentrations and weather conditions. Water depth, percent area coverage of the FTWs and littoral zone emergent plants were varied in order to determine nutrient removal efficiency before implementing in an actual pond. Focus has also been placed on the observations of macrophyte-epiphyte-phytoplankton interactions in order to understand temporal characteristics of ecological phenomena. Water quality parameters included Total Nitrogen, Total Phosphorus, Orthophosphate, Nitrate-Nitrogen, and Ammonia-Nitrogen in addition to in-situ parameters such as pH, Dissolved Oxygen, Temperature and Chlorophyll-a. Results clearly indicate that an FTW filled with sorption media of 80% expanded clay and 20% tire crumb can significantly promote the biomass growth. Different levels of nutrient concentrations did affect the plants' growth and cold temperature in late winter was detrimental to growth. To make the system more viable irrespective of the seasonal weather conditions, the adoption of mixed vegetation is highly recommended in the FTWs implementation.; It is also recommended that, the positioning of the floating wetlands should not be in the vicinity of the outlet of the pond as assimilated nutrient under the mat might increase the nutrient concentration in the discharged water. Finally, One-way ANOVA test is performed to check whether or not these grouped microcosms and mesocosms with differing experimental setup can be deemed statistically significant.<br>ID: 030422696; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.Env.E.)--University of Central Florida, 2011.; Includes bibliographical references (p. 70-74).<br>M.S.<br>Masters<br>Civil, Environmental and Construction Engineering<br>Engineering and Computer Science
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Gorski, Jacob J. "Evidence Supporting Treatment Practice Based Delineation of Stormwater Runoff Zones." PDXScholar, 2013. https://pdxscholar.library.pdx.edu/open_access_etds/1423.
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Particles mobilized by stormwater negatively affect receiving surface waters. Stormwater best management practices (BMPs) can reduce solids along with associated pollutants in runoff but engineers and environmental managers have been long vexed by the problem of choosing the optimal BMP for a given situation. A common BMP process for solids removal is sedimentation. This thesis addresses the question of whether the effectiveness (and thus choice) of a sedimentation device can be estimated (and thus optimized) from the particle size properties of runoff, which, in turn, could be associated with specific runoff zones or land uses. Presented here is a series of experiments to determine the solids-removal capabilities of a manufactured oil-water separator that also removes solids via sedimentation. A statistical model developed from the experimental data shows that, under normal operating conditions, influent particle size can be used to accurately estimate effluent total suspended solids (TSS) for BMPs of this type. Relationships between particle size and particle-bound metal concentrations for Cu, Zn and Pb were then obtained from the literature and incorporated into the model to allow estimates of metal removal efficiencies based on TSS and PSD. The model can be used with an arbitrary particle size distribution (PSD); this allows effluent quality predictions to be made considering that particle sizes entering stormwater BMPs could vary due to anthropogenic, hydraulic or hydrologic factors. To place these experimental and modeling results in the context of an urban environment, samples of deposited stormwater solids were collected from residential areas, commercial areas and an industrial zone in Portland, Oregon, and the PSD of each sample was determined using light obstruction particle sizing. PSDs ranging over sizes from 3μm to 200μm vary among these locations. Areas with high anthropogenic impact were found to have PSDs skewed toward the smallest particle sizes. The statistical model developed here was then used to show that the effluent quality of the BMP tested would differ depending on the locations where solids were collected. The evidence presented in this thesis thus indicates that device performance will correlate with geographic locations or land use zone and validates further investigation into delineating the City of Portland's characteristic runoff zones and using the runoff characteristics of each zone to map it to the most desirable treatment practices.
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Kohlsmith, Emma Rose. "Stormwater Treatment Effectiveness of Established Bioretention Facilities in Portland, Oregon." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/5176.
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Bioretention systems are commonly used to treat and detain stormwater runoff and help mitigate for many negative effects of urbanization. Despite the widespread use of bioretention systems, few field-based studies have assessed how these facilities affect water quality many years after installation. The goal of this project is to assess the pollution reduction effectiveness of lined bioretention facilities that have been in use and functioning for 4-8 years. To meet this objective, this project measured water quality characteristics of stormwater flowing into and out of seven facilities installed throughout Portland, Oregon during real storm events. Stormwater grab samples were taken over a 2-year period during the fall, winter, and spring. Results showed decreased concentrations of total suspended solids (TSS; 94%), ammonia (85%), total copper (59%), total zinc (80%), and dissolved zinc (41%). Results for dissolved copper indicated an overall increase in outflow concentrations of 23%, however variability between facilities was high. These results support other similar findings showing that TSS is effectively reduced by bioretention facilities, even after 4-8 years of use. However, based on this study, effective TSS removal by bioretention facilities does not necessarily equate to equally effective treatment of other pollutants, especially orthophosphate and nitrate, which increased in outflow from the bioretention facilities by 141% and 2070%, respectively. Results of this study indicate that additional research is necessary to determine the significance of the observed increase in nutrients, understand the underlying mechanisms, and test possible design modifications to improve nitrate and orthophosphate removal.
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Wilson, Laura R. "Evaluation of a Constructed Dry Swale for Treatment of Stormwater Runoff." Fogler Library, University of Maine, 2004. http://www.library.umaine.edu/theses/pdf/WilsonLR2004.pdf.
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Larm, Thomas. "Watershed-based design of stormwater treatment facilities : model development and applications." Doctoral thesis, Stockholm : Tekniska högsk, 2000. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3103.
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Thompson, Kyle A. "Evaluating Treatment Approaches for Sustainable Reuse of Greywater, Wastewater, and Stormwater." Thesis, University of Colorado at Boulder, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10792035.
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<p> Water is becoming increasingly scarce; approximately 2 billion people currently live in annual water scarcity, and 3 to 4 billion people are expected to live in water scarcity by 2050 due to population growth alone. Therefore, there is need to determine suitable alternative drinking water sources. Alternative sources present different advantages in terms of supply, initial contamination, and variability. Different technologies may be most effective or sustainable for treating these alternative source waters depending on scale and application (e.g., toilet flushing, irrigation, or potable reuse). Previous reuse research has focused on biological treatment of greywater, passive treatment of stormwater, and reverse osmosis or advanced oxidation for wastewater effluent. The objectives of this dissertation were to (i) study the effectiveness of conventional drinking water treatment (CDWT) for potable reuse of alternative source waters and blends, (ii) compare the environmental sustainability of novel sorbents for micropollutant removal from wastewater effluent, (iii) develop an improved synthetic bathroom greywater that closes matches the characteristics and treatability of real bathroom greywater, and (iv) compare activated carbon and biochar for dissolved organic carbon (DOC) removal from raw and pretreated greywater. </p><p> Bench-scale experiments simulating CDWT achieved high turbidity removal in alternative source waters. Average maximum TOC removal with CDWT was 19%, 27% and 37% for greywater, wastewater effluent, and stormwater, respectively. However, no wastewater effluents and only one stormwater met drinking water regulations for disinfection byproduct formation control. Environmental sustainability was assessed using life cycle methodology. For micropollutant removal from wastewater effluent, wood-based biochar was more sustainable than activated carbon in most environmental impact categories. Higher adsorption capacity was associated with greater environmental benefits. A new synthetic bathroom greywater (SynGrey) was developed that closely matches the median characteristics of forty-nine real bathroom greywaters, and matched the treatability of real bathroom greywater in chlorination, biodegradation, and sorption. Five biochars were screened for greywater treatment, and activated carbon removed more DOC than the best biochar from raw, coagulated, aerated, and rainwater-blended greywater. This research will contribute to the selection and design of effective, sustainable treatment systems for potable and nonpotable reuse of alternative source waters.</p><p>
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Kelley, John Paul. "Performance of Bioswales for Containment and Treatment of Highway Stormwater Runoff." Master's thesis, Temple University Libraries, 2018. http://cdm16002.contentdm.oclc.org/cdm/ref/collection/p245801coll10/id/497950.
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Civil Engineering<br>M.S.Env.E.<br>The focus of this research was to assess the performance of bioswales in mitigating and treating stormwater runoff from highways and to identify critical parameters that influence the load of pollutants from the drainage area. These bioswales are located in Philadelphia and are part of a project initiated by the Pennsylvania Department of Transportation to upgrade a major roadway (Interstate 95) running through the area. The work included sampling and laboratory analysis of runoff water from 9 storm events to characterize concentrations of contaminants coming from the highway and going in to the bioswales. For one storm event, sampling of vadose-zone and ponded water was included to assess how contaminants move or are retained within the bioswale. The various contaminants include solids, nutrients and metals, which have all been shown to be parameters of concern when dealing with stormwater runoff from highways. In addition, a simulated runoff test was performed to assess the potential risk of a very large storm in mobilizing contaminants within the bioswale. Stepwise linear regression in IBM SPSS was used to analyze the runoff data collected. Characteristics of the rainfall (antecedent dry period, total rainfall, rainfall intensity) were selected as potential explanatory variables to predict contaminant concentration or load. Results of the runoff characterization showed contaminant concentrations that fell within range of literature values from a similar drainage area. Estimated annual loads of contaminants were also in range of what has been observed for highway runoff. Vadose-zone and ponded water sampling showed removal of ammonia, total phosphorus and chemical oxygen demand and build-up of nitrate, total nitrogen and TKN. The build-up was likely due to lack of ion interaction with soil particles, which caused the contaminants to remain in the water. Simulated runoff testing showed no potential for contaminant mobilization within the bioswale but did indicate potential areas of contaminant buildup via observation of a dye tracer. Stepwise linear regressions performed in SPSS showed total rainfall as the most significant predictor of suspended solid, nitrate and total phosphorus load in the bioswales. Results also indicate that there are significant differences between the loads observed for the two bioswales monitored.<br>Temple University--Theses
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Alam, Md Zahanggir. "Catch Basin Insert: Characterization and Modelling of Stormwater Treatment at Source." Thesis, Curtin University, 2018. http://hdl.handle.net/20.500.11937/69350.
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This research investigates the hydraulics of catch basin insert (CBI) for treating stormwater at source. Field and laboratory investigations checked the solid removal capacity of geotextiles in CBI. Laboratory experiments also conducted to check the nutrient removal capacity of biochar and alum sludge. A modified CBI is proposed with two chambers. The upper chamber with geotextile basket will capture gross pollutants and lower chamber with adsorbent material will remove nutrients and thus produce cleaner stormwater.
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Newton, David Brooke. "The Effectiveness of Modular Porous Pavement as a Stormwater Treatment Device." Thesis, Griffith University, 2005. http://hdl.handle.net/10072/367825.
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The potential of porous pavement to meet the key stormwater management objectives of peak discharge control, pollutant removal and runoff volume reduction has been recognised for several decades. However, concerns over maintenance and the structural inferiority of porous pavements have led to interest in pavement systems that utilize both porous and impervious pavements. In such systems the porous pavement may act as a treatment device for impervious area runoff. This study examines the extent to which such combined pavement systems are capable of reducing the impacts of urbanisation on downstream hydrology and water quality. To achieve this objective, experimental and numerical investigations were undertaken to quantify the hydrologic, hydraulic and pollutant removal characteristics of modular, lattice pavement, constructed on an impermeable membrane. This type of construction eliminates the potential for differential settlement associated with variations in sub-grade moisture content and avoids the migration of dissolved pollutants to groundwater. Using design scenarios, the numerical models of component processes are combined to investigate the performance of pervious/impervious pavement systems for effective stormwater treatment. A plot-scale field experiment was undertaken to quantify evaporative water loss from this type of pavement. The potential to increase evaporation by incorporating extended detention within the pavement structure was also investigated. Conceptual and numerical models of evaporative water loss from coarse granular media were developed and successfully applied to the experimental data. It is shown that, even without infiltration, this type of porous pavement can substantially reduce runoff volume. However, under subtropical conditions, increasing the amount of water available within the pavement has only a small effect on evaporation. The hydraulic characteristics of porous pavement treating runoff from an impervious area were investigated in an experimental pavement flume. A numerical model was developed to simulate the coupled surface and subsurface flow interactions through the experimental porous pavement. With increasing discharge, surface water runs further onto the porous pavement surface, while the infiltration rate increases sharply towards the leading edge of surface flow. It was found that combined pavement systems can substantially reduce peak stormwater discharges, although the relationships between attenuation, rainfall intensity, rainfall volume and pavement detention time are complex. In general terms, the attenuation provided by porous pavement increases as rainfall intensity becomes larger. However, storm volume has an overriding effect on this relationship. For very short or very long detention times, storms greater than the pavement voids volume receive little attenuation. An intermediate detention time, of the order of 1 to 6 hours, is likely to result in the best average attenuation over the widest range of rainfall intensities and storm volumes.
The results of water quality experiments in the experimental pavement flume demonstrate that the experimental pavement can remove inorganic particulate contaminants, down to approximately 5 microns. The particulate removal performance can be improved by increasing the detention time within the porous pavement. However, little benefit is obtained by increasing detention time beyond about 1 hour. An exponential decay model with only one calibration parameter, adapted from filtration theory for wastewater treatment, is used to predict particulate removal efficiency. This model overcomes some of the deficiencies of the k-C* model, widely employed in the analysis of stormwater treatment. The new model predicts the variation in total concentration and particle size distribution through the pavement, as well as incorporating the effects of varying hydraulic conditions on particulate removal.<br>Thesis (PhD Doctorate)<br>Doctor of Philosophy (PhD)<br>School of Environmental Engineering<br>Full Text
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Alias, Noraliani Binti. "First flush behaviour in urban residential catchments." Thesis, Queensland University of Technology, 2013. https://eprints.qut.edu.au/63811/1/Noraliani_Alias_Thesis.pdf.
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The current state of knowledge in relation to first flush does not provide a clear understanding of the role of rainfall and catchment characteristics in influencing this phenomenon. This is attributed to the inconsistent findings from research studies due to the unsatisfactory selection of first flush indicators and how first flush is defined. The research study discussed in this thesis provides the outcomes of a comprehensive analysis on the influence of rainfall and catchment characteristics on first flush behaviour in residential catchments. Two sets of first flush indicators are introduced in this study. These indicators were selected such that they are representative in explaining in a systematic manner the characteristics associated with first flush.
Stormwater samples and rainfall-runoff data were collected and recorded from stormwater monitoring stations established at three urban catchments at Coomera Waters, Gold Coast, Australia. In addition, historical data were also used to support the data analysis. Three water quality parameters were analysed, namely, total suspended solids (TSS), total phosphorus (TP) and total nitrogen (TN). The data analyses were primarily undertaken using multi criteria decision making methods, PROMETHEE and GAIA. Based on the data obtained, the pollutant load distribution curve (LV) was determined for the individual rainfall events and pollutant types. Accordingly, two sets of first flush indicators were derived from the curve, namely, cumulative load wash-off for every 10% of runoff volume interval (interval first flush indicators or LV) from the beginning of the event and the actual pollutant load wash-off during a 10% increment in runoff volume (section first flush indicators or P).
First flush behaviour showed significant variation with pollutant types. TSS and TP showed consistent first flush behaviour. However, the dissolved fraction of TN showed significant differences to TSS and TP first flush while particulate TN showed similarities. Wash-off of TSS, TP and particulate TN during the first 10% of the runoff volume showed no influence from corresponding rainfall intensity. This was attributed to the wash-off of weakly adhered solids on the catchment surface referred to as "short term pollutants" or "weakly adhered solids" load. However, wash-off after 10% of the runoff volume showed dependency on the rainfall intensity. This is attributed to the wash-off of strongly adhered solids being exposed when the weakly adhered solids diminish. The wash-off process was also found to depend on rainfall depth at the end part of the event as the strongly adhered solids are loosened due to impact of rainfall in the earlier part of the event. Events with high intensity rainfall bursts after 70% of the runoff volume did not demonstrate first flush behaviour. This suggests that rainfall pattern plays a critical role in the occurrence of first flush.
Rainfall intensity (with respect to the rest of the event) that produces 10% to 20% runoff volume play an important role in defining the magnitude of the first flush. Events can demonstrate high magnitude first flush when the rainfall intensity occurring between 10% and 20% of the runoff volume is comparatively high while low rainfall intensities during this period produces low magnitude first flush. For events with first flush, the phenomenon is clearly visible up to 40% of the runoff volume. This contradicts the common definition that first flush only exists, if for example, 80% of the pollutant mass is transported in the first 30% of runoff volume.
First flush behaviour for TN is different compared to TSS and TP. Apart from rainfall characteristics, the composition and the availability of TN on the catchment also play an important role in first flush. The analysis confirmed that events with low rainfall intensity can produce high magnitude first flush for the dissolved fraction of TN, while high rainfall intensity produce low dissolved TN first flush. This is attributed to the source limiting behaviour of dissolved TN wash-off where there is high wash-off during the initial part of a rainfall event irrespective of the intensity. However, for particulate TN, the influence of rainfall intensity on first flush characteristics is similar to TSS and TP. The data analysis also confirmed that first flush can occur as high magnitude first flush, low magnitude first flush or non existence of first flush.
Investigation of the influence of catchment characteristics on first flush found that the key factors that influence the phenomenon are the location of the pollutant source, spatial distribution of the pervious and impervious surfaces in the catchment, drainage network layout and slope of the catchment. This confirms that first flush phenomenon cannot be evaluated based on a single or a limited set of parameters as a number of catchment characteristics should be taken into account. Catchments where the pollutant source is located close to the outlet, a high fraction of road surfaces, short travel time to the outlet, with steep slopes can produce high wash-off load during the first 50% of the runoff volume.
Rainfall characteristics have a comparatively dominant impact on the wash-off process compared to the catchment characteristics. In addition, the pollutant characteristics also should be taken into account in designing stormwater treatment systems due to different wash-off behaviour. Analysis outcomes confirmed that there is a high TSS load during the first 20% of the runoff volume followed by TN which can extend up to 30% of the runoff volume. In contrast, high TP load can exist during the initial and at the end part of a rainfall event. This is related to the composition of TP available for the wash-off.
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Tharp, Rebecca. "Ecological Stormwater Management: Analysis of design components to improve understanding and performance of stormwater retention ponds." ScholarWorks @ UVM, 2018. https://scholarworks.uvm.edu/graddis/934.
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Stormwater runoff from developed land is a source of pollution and excessive flow to waterways. The most commonly employed practices for flow and volume control are stormwater ponds and basins (also referred to as detention and retention ponds). These structures can be effective at controlling peak discharge to water bodies by managing flow timing but are often ineffective at removing nutrients, particularly in dissolved forms. Pond morphology coupled with place-specific characteristics (like soil type and drainage area characteristics) may influence plant community composition in these water bodies. The interaction of physical, chemical, and biological elements in stormwater ponds may affect their water quality performance in more significant ways than previously understood. Floating treatment wetlands (FTW) are floating rafts of vegetation that can be constructed using a variety of materials and are an emerging technology aimed at improving the pollutant removal and temperature control functions of stormwater ponds. Previous studies with field research in subtropical and semiarid climatic regions found incremental nutrient removal improvement correlated with FTW coverage of pond surface area. However, data on their performance in cold climates is lacking from the literature.
This dissertation presents data from a three-year study examining the performance of FTW on stormwater pond treatment potential in cold climate conditions and optimal vegetation selection based on biomass production, phosphorus (P) uptake, and root architectural characteristics that enhance entrapment functionality. To put the FTW pond performance data into context, results from a survey of seven permitted stormwater ponds in Chittenden County, Vermont and the ponds' associated variability in influential internal and external dynamics are also discussed. Pond morphology, drainage area land use, soil types, and biological communities are analyzed for correlative relationships to identify design factors that affect pond performance but are not controlled factors in stormwater system permitting.
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Chowdhury, Anupam. "A framework for determining rainfall parameters for stormwater quality treatment system design." Thesis, Queensland University of Technology, 2018. https://eprints.qut.edu.au/120286/1/Anupam_Chowdhury_Thesis.pdf.
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This study developed an innovative stormwater quality treatment design framework for effective mitigation of urban stormwater pollution. The research method is primarily based on a stormwater quality modelling exercise and an extensive statistical analysis for defining the relationships among rainfall, catchment and stormwater quality characteristics. The identified relationships were translated into a framework, enabling the determination of rainfall parameters and treatment system design specifications. Adopting this framework will enhance treatment system performances leading to greater protection of aquatic ecosystems.
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Coulson, Kelly Mae. "Effect of vegetation in a dissolved metal passive compost stormwater treatment system." Thesis, University of British Columbia, 2009. http://hdl.handle.net/2429/12652.
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A better understanding of the flow and sorption properties of vegetated compost roadsides is needed before such passive, low cost treatment beds can be recommended as a Best Management Practice (BMP) to treat metals in stormwater runoff during the non-vegetative growth and high rainfall period between Oct. and April in the Pacific NW. The effect of four different flow rates between 70 and 900 mL/min on retention time in 12° sloped compost and grassed compost beds (1.02 m x 0.254 m x 0.10 m deep) were examined using bromide as a conservative tracer. Zinc sorption (at 3.0 mg/L, pH=5.6, 11°C) buffering potential and turbidity levels were examined in both beds at 264 mL/min. The mean particle size of the compost was 0.0063 m.
Roots that had amassed for 7 months prior to the experiments increased retention time only at the low flow rate of 70 mL/min. At this flow rate, most of the flow was concentrated along the bed bottom where the root mass was thickest. Excepting at the two lowest flow rates, the drainable water volume in the compost bed was higher than in the grassed compost bed. Bed composition in duplicated trials did not affect zinc breakout at 264 mL/min when retention time and percentage of the bed utilized were similar in both bed types. Breakout time in the beds was approximately 230 hr. Both bed types buffered influent pH to as high as 7, and this ability decreased over time (F=50-200, p<<<0.0005). Initial turbidity readings for both treatment beds were found to be significantly higher than the runtime turbidity. The grassed compost bed produced lower initial and runtime effluent turbidities (tstat=3.18-. 5.14, p=.0005 to <<0.0001). Results indicated that grassed compost beds are as effective as compost beds at a flow rate of 264 mL/min for water holdback, pH buffering and zinc metal sorption, but grassed compost bed effluent would likely be clearer. Results will be used to design BMPs for industrial sites that have similar flow and zinc runoff levels. Future research should focus on different metal concentrations and species.
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Le, Bel Paul David. "Performance Evaluation of a Low Impact Development Retrofit for Urban Stormwater Treatment." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/48656.
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The goal of Low Impact Development (LID) is to mimic the pre-development hydrologic regime of a catchment through infiltration, filtration, storage, evaporation, and detention of post-development runoff using small-scale hydrologic controls close to the source. A LID facility located in Northern Virginia was examined for pollutant removal and hydrologic performance. The treatment train included four in-line grass swales followed by a bioretention cell with a gravel base. The facility retained 85% of the rainfall. Influent and effluent pollutant loads were calculated using three common substitution methods for datasets censored by values below the analytical detection limit. The Summation of Loads (SOL) method was used to facilitate understanding of how data censoring affected performance results when substitution methods were used. The SOL analysis showed positive removal performance for most nutrient species, sediment, oxygen demanding substances, selected trace metals and total petroleum hydrocarbons. Negative performance was observed for oxidized nitrogen, total dissolved solids and oil & grease. LID facility influent and effluent loads were also compared using the Effluent Probability Method (EPM). The EPM analysis showed statistically significant (p d 0.05) pollutant load removal performance over the entire range of sampled events for total suspended solids, total phosphorus, total nitrogen, total Kjeldahl nitrogen, ammonia nitrogen, chemical oxygen demand, copper, zinc and alkalinity. EPM analysis did not show significant removals of oxidized nitrogen, total dissolved solids, orthophosphate phosphorus and hardness.<br>Master of Science
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Holland, Jeff F. "Nonideal and Pulsed Flow: Applying Residence Time Distributions to Stormwater Treatment Wetlands." The Ohio State University, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=osu1406812534.
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Fritioff, Åsa. "Metal accumulation by plants : evaluation of the use of plants in stormwater treatment." Doctoral thesis, Stockholm University, Department of Botany, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-613.
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<p>Metal contaminated stormwater, i.e. surface runoff in urban areas, can be treated in percolation systems, ponds, or wetlands to prevent the release of metals into receiving waters. Plants in such systems can, for example, attenuate water flow, bind sediment, and directly accumulate metals. By these actions plants affect metal mobility. This study aimed to examine the accumulation of Zn, Cu, Cd, and Pb in roots and shoots of plant species common in stormwater areas. Furthermore, submersed plants were used to examine the fate of metals: uptake, translocation, and leakage. Factors known to influence metal accumulation, such as metal ion competition, water salinity, and temperature, were also examined. The following plant species were collected in the field: terrestrial plants – <i>Impatiens parviflora</i>, <i>Filipendula ulmaria</i>, and <i>Urtica dioica</i>; emergent plants –<i> Alisma-plantago aquatica</i>, <i>Juncus effusus</i>, <i>Lythrum salicaria</i>, <i>Sagittaria sagittifolia</i>, and <i>Phalaris arundinacea</i>; free-floating plants – <i>Lemna gibba</i> and <i>Lemna minor</i>; and submersed plants – <i>Elodea canadensis</i> and <i>Potamogeton natans</i>. Furthermore, the two submersed plants, <i>E. canadensis</i> and <i>P. natans</i>, were used in climate chamber experiments to study the fate of the metals in the plant–water system.</p><p>Emergent and terrestrial plant species accumulated high concentrations of metals in their roots under natural conditions but much less so in their shoots, and the accumulation increased further with increased external concentration. The submersed and free-floating species accumulated high levels of metals in both their roots and shoots. Metals accumulated in the shoots of <i>E. canadensis</i> and <i>P. natans</i> derived mostly from direct metal uptake from the water column.</p><p>The accumulation of Zn, Cu, Cd, and Pb in submersed species was in general high, the highest concentrations being measured in the roots, followed by the leaves and stems, <i>E. canadensis</i> having higher accumulation capacity than <i>P. natans</i>. In <i>E. canadensis</i> the Cd uptake was passive, and the accumulation in dead plants exceeded the of living with time. The capacity to quickly accumulate Cd in the apoplast decreased with successive treatments. Some of the Cd accumulated was readily available for leakage. In <i>P. natans,</i> the presence of mixtures of metal ions, common in stormwater, did not alter the accumulation of the individual metals compared to when presented separately. It is therefore, proposed that the site of uptake is specific for each metal ion. In addition cell wall-bound fraction increased with increasing external concentration. Further, decreasing the temperature from 20ºC to 5ºC and increasing the salinity from 0‰ to 5‰ S reduced Zn and Cd uptake by a factor of two.</p><p>In <i>P. natans</i> the metals were not translocated within the plant, while in<i> E. canadensis </i>Cd moved between roots and shoots. Thus,<i> E. canadensis</i> as opposed to <i>P. natans</i> may increase the dispersion of metals from sediment via acropetal translocation. The low basipetal translocation implies that neither <i>E. canadensis</i> nor <i>P. natans</i> will directly mediate the immobilisation of metal to the sediment via translocation.</p><p>To conclude, emergent and terrestrial plant species seem to enhance metal stabilization in the soil/sediment. The submersed plants, when present, slightly increase the retention of metals via shoot accumulation.</p>
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Fritioff, Åsa. "Metal accumulation by plants : evaluation of the use of plants in stormwater treatment /." Stockholm : Department of Botany, Stockholm University, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-613.
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Curtis, Jeffry G. "Laboratory-scale investigations of stormwater treatment in the Lake Tahoe Basin using chemical coagulants." abstract and full text PDF (free order & download UNR users only), 2007. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3258940.
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Morgan, Catherine. "Assessment of the design of stormwater ponds for flow attenuation and water quality treatment." Thesis, Heriot-Watt University, 2008. http://hdl.handle.net/10399/2036.
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(n order to reduce the impact of flooding and water quality degradation in urban areas sustainable urban drainage systems (SUDS) are increasingly being implemented throughout the UK. The thesis is concerned with one such type of system, namely retention ponds. With an absence of continuous long-term monitoring data to demonstrate how well these ponds perform in practice, a mathematical model was developed to investigate their flow attenuation and water quality enhancement characteristics. Simulations obtained with the model aimed to quantify how well ponds, designed using current UK guidance, are likely to perform now and under climate change scenarios. Furthermore, the model was used to study the effect of innovations in pond design. Initial modelling concerned ideal, generic ponds, with the knowledge gained being used to guide a case study on Linbum Pond in Scotland. Results show that the volume of temporary storage and the design of the outlet device are both of critical importance in meeting both flow attenuation and water quality enhancement targets. Furthermore, results also indicate the importance of dilution in achieving water quality targets. Simulations show that not only should a large permanent pool be provided but that water quality performance improves significantly when ~his volume is provided using larger surface areas as opposed to by deeper permanent pools. The assimilation of the knowledge gained in the study has enabled a set of improvements to current retention pond design to be proposed.
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MacLure, Ryan Scott. "Performance of a Catch Basin Filter and Leachate from Biocidal Media for Stormwater Treatment." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/47.
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The feasibility of installing biocidal beads into a catch basin filter insert for simultaneous stormwater disinfection and contaminant removal was tested. The catch basin filter insert (DrainPac®) was tested for its sediment, oil and grease, and coliform bacteria removal efficiency in conjunction with bench-scale testing of biocidal polymer beads. DrainPac® catch basin filters are composed of a metal frame, polypropylene filter fabric, and a high-density polymer support basket, and are installed below storm drains. A 12 x 41 in. DrainPac® filter (United Stormwater, Inc.) insert was set in a flume that simulated a large-scale catchment basin. Pond water was gravity fed to the flume at flow rates up to 200 gpm. The pond water contained fine sediments at concentrations ranging from 30-50 mg/L. The biocidal beads were tested in a small laboratory column for potential application to stormwater treatment. The head loss through the clean filter insert varied from 0.5 cm at 20 gpm to 9.1 cm at 200 gpm. Head loss of 21.5 cm occurred after 625 g of solids were added to the filter at 200 gpm at which point water began bypassing the filter fabric and flowing through the mesh screen. The highest flow rate that could be filtered through the loaded filter was 80 gpm. The DrainPac® filter removed total suspended solids with efficiencies ranging from 83% to 91% at flow rates of 20 to 200 gpm, with higher removal efficiencies at lower flow rates. The oil and grease removal efficiency of the DrainPac® filter ranged from 40% to 82%. The DrainPac® filter exhibited no removal of coliform bacteria under these test conditions. Biocidal brominated polystyrene beads, developed by Dr. S. D. Worley at Auburn University, were tested in a 1-cm diameter laboratory column apparatus for leaching of bromine compounds, which is important for determining if the filters will meet water quality regulations of the receiving waters. Removal efficiencies of coliform bacteria were tested in a companion study by Cal Poly graduate student Alex Bowerman. Pond water was passed through a 1-cm thick bed of beads in an up-flow direction. Leachate was analyzed for bromine, bromide, and bromoform. Leaching from both 0.3-mm and 0.8-mm biocidal beads was tested in the column apparatus. Samples collected for bromoform analysis were quenched with sodium thiosulfate, and the time before samples were quenched had a drastic effect on bromoform concentrations. Samples quenched after the collection of the total sample were assumed to be the most realistic for stormwater conditions since stormwater entering catch basins isn’t immediately discharged into its receiving waters. Effluent from a 1-cm bed of 0.3-mm beads at 0.56 mL/sec contained the following average concentrations: 0.47 mg/L bromine, 2.45 mg/L bromoform, and 0.53 mg/L bromide. The same conditions for 0.8 mm beads resulted in effluent containing the following average concentrations: 0.27 mg/L bromine, 0.06 mg/L bromoform, and 0.50 mg/L bromide. The much lower concentrations of bromine measured in the 0.8-mm bead leachate was likely due to the greater surface area of the smaller beads. The greater leaching of bromoform from the 0.3 mm beads may be partly attributed to the greater surface area of the smaller beads, but also the manufacturer of the beads reported that different production methods were used for the 0.3 mm beads. Higher bromine compound concentrations were found at lower flow rates, due to the longer contact times with the beads. Deionized (DI) water that was used to initially wet the biocidal beads before passing pond water through the column was also analyzed for bromoform. The DI flush water from the 0.3 mm beads contained 1.25 mg/L bromoform at a flow rate of 0.28 mL/sec. Bromoform concentrations in the DI flush water from the 0.8 mm beads at the same flow rate were below detection. Bromoform is expected to be formed as bromine is reduced to bromide by the presence of organics. Since there are no organics present in DI water to form such high concentrations of bromoform as those found from the 0.3-mm bead DI flush water, it appears that bromoform could have leached from the surface of the 0.3 mm beads. The longevity of the bromine treatment of the biocidal beads was tested on one set of 0.3-mm beads by simulating five use cycles, and also by testing another set of beads after dry storage. Each use cycle was simulated by pumping pond water through a 1-cm bed of 0.3 mm beads at 0.56 mL/sec for one hour and then connecting the column to an air pump to dry for 23 hours. After five simulated uses, leachate from the beads showed only a slight reduction in concentrations of bromine and bromide (21% and 4% less than fresh beads, respectively), while the concentration of bromoform was nearly 100 times less. The drastic decrease in bromoform concentration suggests that after five simulated uses, much of the bromoform was exhausted or conditions for the formation of bromoform were no longer present. For the dry storage test, 0.3 mm beads were wetted with 1-L DI water and then stored dry for 162 days. Then pond water was pumped through the column at 0.56 mL/sec and the leachate was analyzed. After dry storage for 162 days, the leachate showed no reduction in bromine concentrations compared to fresh beads, a 97% reduction in bromoform, and a 30% increase in bromide concentrations. This significant reduction in bromoform could be due to the volatilization of bromoform off the surface of the 0.3 mm beads during dry storage. The 0.3 mm beads are no longer being manufactured, and leachate from the 0.8 mm beads contained bromoform at concentrations below the potable drinking water maximum contaminant level of 80 µg/L. Under all tested conditions, bromine, bromide, and bromoform are present in the leachate from the biocidal beads, and thus their applicability for stormwater disinfection depends on the longevity of the bromine compounds in receiving waters, and on the regulations governing these compounds.
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Atkinson, Thomas. "The end of the line: Managing unplanned changes in an urban stormwater treatment wetland." Thesis, Atkinson, Thomas (2015) The end of the line: Managing unplanned changes in an urban stormwater treatment wetland. Masters by Research thesis, Murdoch University, 2015. https://researchrepository.murdoch.edu.au/id/eprint/25675/.
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This study looked at the problem of constructed wetlands deviating from their initial design parameters to the detriment of treatment performance, in the context of a contemporary storm water treatment wetland in Perth, Western Australia. The study investigated the system components and internal process management of the wetland, and their impact on its capacity to remove nutrients and contaminants from urban stormwater over a seven year period. It found that a designed feature of the wetland, specifically permanent inundation, compromised the ability of the wetland to accommodate inputs of organic material and sulfate, resulting in intensified substrate reduction. Strongly reduced sediments containing dissolved sulfides and other phytotoxins accumulated to concentrations sufficient to cause vegetation dieback; and the cover and health of the emergent macrophytes within the wetland declined dramatically. Loss of emergent macrophytes coincided with changes in nitrogen removal, not in the reduction of nitrate but in the increase of ammonium, consistent with the increasingly reduced conditions. There was not a significant change in phosphorus removal, perhaps suggesting that phosphorus removal was primarily through physical means (sedimentation) rather than chemical. It was considered that the broadscale deoxygenation of the wetland was detrimental both to its nutrient removal capacity and biodiversity attributes. Applying active adaptive management, a trial was conducted involving manipulation of inundation depths, such that redox potentials were increased in a passively aerated treatment. The growth of the emergent macrophyte species Baumea articulata was demonstrated to improve significantly within this treatment, suggesting a similar modification to the hydraulics of the wetland could improve emergent macrophyte growth. The importance of macrophytes to treatment processes is well established and so this modification is expected to improve the water treatment function of the wetland. The study successfully demonstrated that the design of urban constructed wetlands must be site specific and adaptive to ensure specific ecosystem services, such as water treatment, are maintained.
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Svensson, Henric. "Leaching Test with Sawdust from Different Tree Species : Appropriateness of using them as adsorption media in wastewater and in stormwater treatment." Thesis, Linnéuniversitetet, Institutionen för naturvetenskap, NV, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:hik:diva-2627.
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Abstract Bio energy in form of woodchips and sawdust is today commonly stored outdoors in heaps on hardened surfaces, exposed to weather and wind. Any water leaching from these heaps have the potential to be toxic to the environment. This paper examines the quality of the water leaching from heaps of four different tree species (oak, pine, maple and beech), by analysing different parameters such as pH, conductivity, colour, COD, BOD7, tannins & lignins (T&L) and phenols. The results show significant higher leaching values of COD, phenols, T&L and colour from oak compared to the other tree species (pine, maple and beech). These leached substances from woodchips and sawdust were shown in the BOD7 tests and BOD7/COD ratio values to be hard to biodegrade and are therefore not easily removed from the water. Hence it is important that wood-based fuel storage conditions are considered in bio energy generation schemes to ensure that the environmental benefits of using woodchips and sawdust instead of traditional fuel are not offset by the potential harm of inappropriate storage. The investigation further showed that leaching of highly toxic substances such as phenols can be up to 10 times higher for one tree type (oak) than another (pine, beech and maple). This difference could potentially be found for other tree species not characterized in this study. Therefore, it is important to consider the constitution of the heaps to be able to apply appropriate storage conditions to avoid these toxic substances in the leached water reaching sensitive watercourses. As some of these substances are hard to biodegrade the treatment applied need a long retention time. Another problem is the carbon: nutrient ratio, this water has a high carbon content compared to phosphorus and nitrogen content which might prevent an efficient biodegradation. Adjusting C:N:P ratio with low cost amendments might raise the performance of the biodegradation in for instance, a constructed wetland.
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Good, Joseph Francis. "Water quality treatment and hydraulic efficacy of laboratory and field rain gardens." Thesis, University of Canterbury. Department of Civil and Natural Resources Engineering, 2011. http://hdl.handle.net/10092/5895.
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Urbanisation leads to increases in stormwater runoff, resulting in elevated contaminant (e.g. metal, sediment, and nutrient pollutant) loads, decreased local infiltration and greater peak flow intensities. Heavy metal contaminants of concern, primarily copper (Cu), lead (Pb), and zinc (Zn), originate from a variety of sources including wear-and-tear of vehicle parts, corrosion of alloy roofs, legacy petroleum contamination, and multifarious construction practices. Different technologies have been used to mitigate stormwater runoff, ranging from traditional drainage networks fitted with concrete proprietary devices (e.g. vortex sediment separators and filters) to more environmentally integrated sustainable solutions.
Rain gardens, a type of Sustainable Urban Drainage System (SUDS) or Water Sensitive Urban Design (WSUD), are employed to control stormwater peak flows and runoff volumes and simultaneously reduce contaminant loads to neighbouring waterways through biologically-active landscaped design. Despite increases in use of rain gardens as a best management practice (BMP) to treat urban stormwater runoff, there is a dearth of knowledge about their treatment and infiltration performance worldwide. It is believed that incorporating topsoil into rain garden design is likely to improve contaminant removal efficiencies (Davis et al. 2001; ARC 2003; Fletcher et al. 2004; Carpenter and Hallam 2010), but design recommendations are not informed by performance data which is limiting. Performance data is necessary for understanding the long-term responses of bioinfiltrative treatment systems and for modelling efforts aiming to predict their mitigation behaviour (Fletcher et al. 2004).
In order to evaluate the influence of substrate composition on stormwater treatment and hydraulic effectiveness in rain gardens, mesocosm-scale (180 L, 0.17 m2) laboratory systems were established. Saturated (constant-head) hydraulic conductivity was determined before and after contaminant (Cu, Zn, Pb and nutrients) removal experiments on three rain garden systems comprising various proportions of organic topsoil. Raw stormwater runoff from a neighbouring Christchurch city catchment was collected, characterised, and applied in the removal efficiency experiments. The system with only topsoil had the lowest saturated hydraulic conductivity (160 mm/hr initial to 164 mm/hr final) and poorest metal (Cu, Zn) removal efficiency (Cu 0.3%, Zn 60.5% and Pb 89.5%) at a ‘standard’ contaminant loading rate (Cu = 5.99 ± 0.73 µg/min, Zn = 57.89 ± 6.06 µg/min, Pb = 13.65 ± 2.80 µg/min). The sand-only system demonstrated good metal removal (Cu 56.4%, Zn 73.5%, and Pb 81.6%) with hydraulic conductivity (up to 805 mm/hr) adequate for practical implementation (i.e. greater than the 13 mm/hr minimum requirement (ARC 2003; MDE 2009; SFPUC 2009)). Overall, total metal amounts in the effluent were <50% of influent loads for all experiments, with the exception of Cu in the topsoil-only system, whose removal was negligible (0.3%). Greater metal removal was observed when effluent pH was elevated (up to pH 7.38). The pH increase (from an initial pH of 6.23 in raw stormwater) was provided by the calcareous sand, whereas the topsoil-only system lacked an alkaline source. Consequently, organic topsoil had poorer contaminant removal due to higher dissolved metal fractions, which are more difficult to immobilise at the lower pH. The relationship between pH and dissolved fraction was highly significant (Pearson’s Correlation, p < 0.0001, df = 74) for Cu, Zn, and Pb.
Mesocosm-scale systems were then re-established with a calcareous substrate supplement to quantify the effects of pH augmentation on contaminant removal and hydraulic efficiencies. Mussel shells, a waste product from the shell-fish industry, were employed in two different volumetric proportions. Metal removal efficiency was increased in systems with mussel shells (Cu up to 46.6%, Zn up to 80.2%, Pb up to 88.7%) compared to the topsoil-only system (Cu 27.5%, Zn 55.5%, Pb 81.0%). Larger increases in removal efficiency were seen for Cu and Zn because increases in pH from mussel shell enhanced particulate fractions, which are easier to remove in filtration systems, while Pb is mainly in the particulate form at influent pH (Morrison et al. 1990). Effluent from systems with mussel shells also had higher hardness (hardness up to 101.7 mg/L as CaCO3) compared with 22.4 mg/L as CaCO3 in topsoil-only effluent. Hardness reduces metal ecotoxicity (Hyne et al. 2005). Results of these experiments show that mussel shells are a promising rain garden substrate capable of increasing metal removal efficiency and also decreasing metal ecotoxicity in effluent of bioinfiltration systems.
Concurrently, an operational field-scale “rain garden” (42 m3; 60 m2) in Christchurch was monitored for hydraulic throughput and contaminant removal. The field system performed extremely well at mitigating peak flows, detaining water throughout storm events and removing total suspended solids (TSS) (90.6% average removal). However, the system failed to reduce effluent median total metal concentrations (Cu = 15.9 µg/L, Zn = 139.6 µg/L, Pb = 11.7 µg/L) below relevant ANZECC guidelines (Cu = 1.8 µg/L, Zn = 15.0 µg/L, Pb = 5.6 µg/L) highlighting the opportunity to optimise these field designs to improve metal removal.
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Jonsson, Linnéa, and Amanda Leima. "Dagvattenhantering vid flaskhalsområden : Klimatförändringar och vägen mot hållbar dagvattenhantering i Bollnäs." Thesis, Högskolan i Gävle, Miljövetenskap, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-32973.
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Flooding from extreme rainfall is already taking place today in Sweden's urban areas. In order tocreate sustainable stormwater management that reduces the risk of flooding, various factorsshould be taken into account such as the choice of method for management. Bottlenecks in thestormwater system mean wells with undersized outlet pipes. A bottleneck area in Bollnäs urbanarea has already caused flooding. The aim of this study is to investigate if there are more similarareas and to contribute to sustainable stormwater management for Helsinge Vatten. Themethods chosen for the study were a literature study and a case study with simulation andcalculations. The literature study was conducted to see how stormwater is handled and what theclimate looks like. The case study was conducted to evaluate the flows that occur during heavyrains. In the case study, a terrain model was first made that showed drainage directions andwater dividers. The calculations in the case study were based on the rational method forcalculating design flow. The climate is changing and as the temperature rises, so does therainfall. The risk of extreme weather increases as the annual average temperature rises and aglobal increase in rainfall intensities has occurred. In Bollnäs, the annual average temperaturehas risen since the measurements began in 1969. In the future, the average temperature can beexpected to rise to 3-5 degrees until the end of the century in Gävleborg. In heavy rain, floodscan occur, they are called pluvial floods and can cause major damage to properties and roads,among other things. There are many methods for developing and making the stormwatersystem more sustainable. Among other things, there is something called blue-greeninfrastructure and this involves green surfaces in the management of stormwater. There, forexample, the water is allowed to infiltrate, evapotranspire or slowly pass on into the system.These solutions also have other benefits, they meet several social needs and can bring ecosystemservices. After the simulation that was carried out, 37 catchment areas could be observed andcalculations for design flow were made based on, among other things, the area in thesecatchment areas. Sustainable stormwater management can be introduced in Bollnäs urban area,when new guidelines and greater cooperation between Helsinge vatten and Bollnäs municipalityare needed. Sustainable stormwater management could reduce the risk of floods in bottlenecks.However, it is not possible to locate any bottlenecks in Bollnäs urban area due to missinginformation about the storm sewers in Bollnäs urban area. More studies would be needed tolocate bottlenecks.<br>Översvämningar från extrem nederbörd sker redan idag i Sveriges tätorter. För att skapa hållbardagvattenhantering som minskar översvämningsrisken bör olika faktorer tas i beaktning somexempelvis val av metod. Flaskhalsar i dagvattensystemet innebär brunnar medunderdimensionerade utloppsledningar. Ett flaskhalsområde i Bollnäs tätort har redan orsakatöversvämningar. Detta arbete går ut på att undersöka om det finns fler liknande områden ochbidra till hållbar dagvattenhantering för Helsinge Vatten. Metoderna som valdes för arbetet varen litteraturstudie och en fallstudie med simulering och beräkningar. Litteraturstudiengenomfördes för att se hur dagvatten hanteras och hur klimatet ser ut. Fallstudien genomfördesför att utvärdera vilka flöden som uppkommer vid kraftiga regn. I fallstudien gjordes först enterrängmodell som visade dräneringsriktningar och vattendelare. Beräkningarna i fallstudienutgick från rationella metoden för beräkning av dimensionerande flöde. Klimatet förändras ochnär temperaturen stiger så stiger också nederbörden. Risken för extremväder ökar till följd avatt årsmedeltemperaturen ökar och en global ökning av nederbördsintensiteter har skett. IBollnäs har årsmedeltemperaturen ökat sedan mätningarna började 1969. I framtiden kanmedeltemperaturen väntas öka upp mot 3-5 grader fram till slutet av seklet i Gävleborg. Vidkraftiga regn kan översvämningar uppstå, de kallas pluviala översvämningar och kan orsaka storaskador på bland annat fastigheter och vägar. Det finns många metoder för att utveckla och göradagvattensystemet mer hållbart. Bland annat finns det något som kallas blågrön infrastruktur (BGI) och detta involverar gröna ytor i hanteringen av dagvatten. Där får vattnet till exempelinfiltrera, evapotranspirera eller långsamt ledas vidare i systemet. Dessa lösningar har ocksåandra fördelar, de tillgodoser flera sociala behov och kan medföra ekosystemtjänster. Efter densimulering som utfördes kunde 37 avrinningsområden observeras och beräkningar fördimensionerande flöde gjordes utifrån bland annat arean på dessa områden. I Bollnäs tätort kanhållbar dagvattenhantering införas, då behövs nya riktlinjer och ett större samarbete mellanHelsinge Vatten och Bollnäs kommun. Hållbar dagvattenhantering skulle kunna minska riskenför översvämningar vid flaskhalsar. Däremot går det inte att lokalisera några flaskhalsar i Bollnästätort på grund av saknad information om dagvattenledningarna i Bollnäs tätort. Fler studierskulle behövas för att lokalisera flaskhalsar.
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Dorman, Michael E. "A methodology for the design of wet detention basins for treatment of highway stormwater runoff." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08142009-040351/.
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Arias, Lopez José Luis. "Vertical-flow constructed wetlands for the treatment of wastewater and stormwater from combined sewer systems." Phd thesis, INSA de Lyon, 2013. http://tel.archives-ouvertes.fr/tel-00961202.
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French vertical-flow constructed wetlands (VFCW) directly treating raw wastewater are known to perform well on for SS, COD and nitrification. They are also known to robustly cope with hydraulic overloads during rainfall events. Although numerous systems have been installed in areas equipped with a combined sewer, the limits of stormwater acceptance remain ill-defined and need to be improved. Looking at the various VFCW designs and usages reported in the literature, it is difficult to draw any consensus on their hydraulic limits. Consequently, designing VFCW to accept hydraulic overloads is a complex task, as local context strongly impacts inlet flows produced during rainfall events. Dynamic models appear a requisite for filter design in such cases. Numerical CW models have essentially focused on horizontal flow, with few attempting to study VFCW dynamics which are more commonly tackled via mechanistic models. Although mechanistic models are powerful tools for describing processes within the VFCW, they are generally too complicated to be readily used by designers. The choice between detailed description and easy handling will depend on the modelling aims. If the aim is a global design tool, simplified models offer a good alternative. However, the simplified models geared to studying VFCW dynamics are extremely reduced. They are easy-handling for design and well-adapted to specific purposes (combined sewer overflow -CSO- treatment) but not necessarily to VFCW treating combined sewer wastewater, where long-term infiltration rates vary significantly. Consequently, this PhD thesis work focused on developing a simplified hydraulic model of VFCW to guide designers through the process of adapting VFCW systems to treat domestic wastewater in both dry and rain events. The simplified model makes it possible to link (i) hydraulics, by simulation of ponding time variations, (ii) biological performances, by establishing "dysfunction alerts" based on treatment performance assessment and variations in online N forms effluent from the young VFCW. These "dysfunction alerts" plot the maximal hydraulic load that a filter can accept without compromising its biological activity. The simplified model was used to model long-term hydraulics in the VFCW (i) to analyze the impact of local context and filter design on hydraulic overload acceptance (using "dysfunction alerts" and bypass discharges) and (ii) to propose VFCW designs for accepting hydraulic overload in different contexts. The modelling demonstrates that VFCW can limit days with bypass discharges to less than 20 times per year without jeopardizing filter performances. Moreover, the most problematic scenario on stormwater treatment remains a watershed with high imperviousness coefficient and low slope under a Bretagne-type climate, demonstrating that the filter is more sensitive to periodicity and duration than to intensity of rainfall events.
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Lundgren, Lovisas. "Metal Removal Efficiency of Five Filter Media Intended for use in Road Stormwater Treatment Facilities." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-292146.
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Roads, buildings, vehicles, and human activities cause spreading of pollutants, which partly end up in stormwater. The pollutant load contains solid particles of various size, hydrocarbons, organics, metals, nutrients, and microorganisms, which can have negative effects on water quality of surface-, coastal- and ground waters. Furthermore, urban development causes hardening of ground and reduced soil permeability that promotes rapid runoff during precipitation. The conversion from permeable to impermeable surfaces therefore lead to increased volumes stormwater but also decrease in stormwater water quality. Stormwater runoff metals are bound to various particles or occur in the dissolved fraction which is more toxic to aquatic life. Infiltration to soil, sand or other media is common practice to reduce runoff and filtrate metals and many treatment facilities and filter media have therefore been assessed for their metal removal efficiencies. High metal removal is often achieved for total metals, but removal of dissolved fraction remains elusive in many studies. Hence the importance of evaluate removal of dissolved metals before application to stormwater treatment facilities. The experimental column study of metal removal using commercially available reactive filter media showed that all filter media removal efficiencies in the order of zinc > copper > nickel. Removal efficiencies of chromium and lead were not considerably higher in tested filter media compared to the reference filter sand. Two filter media also leached chromium during the initial part of the experiment.<br>Vägar, byggnader, fordon och mänskliga aktiviteter orsakar spridning av föroreningar av vilka en del förekommer i dagvatten. Urban bebyggelse orsakar också hårdgörande av ytor och reducerar jordens permeabilitet vilket skapar snabb avrinning vid nederbörd. Avrinningen innehåller bland annat partiklar, kolväten och andra organiska ämnen, metaller, näringsämnen och mikroorganismer vilka kan ha negativa effekter på yt-, kust- och grundvatten. Omvandlingen till hårdgjorda ytor orsakar därför både ökade volymer avrinning och sämre vattenkvalité. Metaller i dagvatten är ofta bundna till olika partiklar eller förekommer i löst form där den lösta formen anses vara mest miljöfarlig. Infiltration i jord, sand eller annan media är vanliga sätt att reducera avrinning och filtrera metaller. Hög förmåga att avskilja metaller kan ofta hittas för totala koncentrationen av metall men avskiljning av den lösta formen är ofta oklar. Utvärdering av olika filtermaterials förmåga att reducera lösta metaller är därför av särskilt intresse. Kolonnförsöken gjorda för att utvärdera metallavskiljningskapacitet med kommersiellt tillgängliga reaktiva filtermaterial har i denna uppsats visat att filtermaterialen har högst procentuell avskiljning för zink följt av koppar och därefter nickel. Krom och bly avskiljs inte mer i dessa filtermaterial än vad de gör i sandfilter. Två av filtermaterial läckte dessutom initialt höga koncentrationer krom.
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McQueen, Andrew D. "Characterization of campus parking lot stormwater and remediation of risks using constructed wetland treatment systems." Connect to this title online, 2008. http://etd.lib.clemson.edu/documents/1239894297/.
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Rydholm, Fredrik. "Sorption of Stormwater Pollutants for Five Material Mixtures: A batch Equlibrium Study." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-86150.
Full textAbstract:
Blue-green infrastructure have been more lucrative during the last 30 years, since urbanizationbrings more impervious surfaces that increases stormwater runoff volumes. Amongst thedifferent blue-green infrastructures there are e.g., constructed wetlands and swales. Blue-greeninfrastructure means more natural management of the stormwater, such as infiltration. Forinfiltration of water, the hydraulic conductivity is an important parameter, but also the abilityto remove dissolved pollutants. In literature, various studies of filter materials are only testedfor single dissolved pollutants, which might be a disadvantage as this does not represent fieldconditions where metals usually co-exist. Economic costs are also an important parameter,unfortunately not always targeted in research. In this thesis, the efficiency of five different material mixtures for removing typical dissolvedstormwater pollutants: chromium (Cr), copper (Cu), nickel (Ni), phosphorus (P), lead (Pb) andzinc (Zn) were studied. The mixtures were following: 1) crushed rock + soil (RO_SO) 2)crushed rock + soil + LECA 4/10 + biochar (RO_SO_BC_LC4). 3) crushed rock + soil + LECA10/20 + biochar (RO_SO_BC_LC10). 4) Soil (SO). 5) crushed rock + soil + biochar(RO_SO_BC). This study was a part of blue-green investments that is being made in Östersundmunicipality and the use of low-cost materials for stormwater treatment are examined. The study was made using batch equilibrium tests, to determine the sorption capacity fordifferent material mixtures, using dissolved metal- and P-solutions. The measured data werefitted to Freundlich, Langmuir, Temkin, Dubinin-Radushkevich and Redlich-Petersonisotherms. Economic feasibility has also been compared between the material mixtures.Results showed that SO had the best sorption capacity for all metals and P, with rankingPb > Cr > Cu > Ni > Zn for the metals. All material mixtures showed a removal efficiency of79-99%, at the lowest concentration (1mg/L) for the metals and 31-62% for the lowestconcentration of P-single solution (1mg/L). Using additional materials in the mixtures, such asbiochar, slightly improved the sorption capacities of Pb and P. Redlich-Peterson isothermsprovided the best fits to the data. An economic evaluation of the ingoing materials shows thatSO and RO_SO are undoubtedly the most feasible alternatives for removal of targeted metalsand P.
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Dietrich, Monique Louise. "A monitoring programme to assess the use of a natural wetland for stormwater treatment in Calgary." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ38580.pdf.
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Niven, Daniel. "The Effectiveness of Local Stormwater Treatment Devices: A Case Study of the Carrara Catchment, South-East Queensland." Thesis, Griffith University, 2006. http://hdl.handle.net/10072/366906.
Full textAbstract:
With the ever-increasing focus on the environment and the adverse effects that
humanity has had, there has become a need to create means of sustaining the
environment rather than destroying it. The impact of urbanisation on Stormwater runoff
has included increased amounts of pollutants entering the waterways, which causes
problems ranging from being aesthetically unpleasing to causing immeasurable
damage, such as destroying the sea grass beds in Moreton Bay.
The overall aim of this research was to investigate the effectiveness of installing local
catchment water quality treatment devices on the regional ‘whole of catchment’ water
quality. This was investigated specifically for South-East Queensland conditions by
researching the Carrara Catchment on the Gold Coast through the collection of water
quality data and modelling of the water quality.
The research has shown that within Queensland, water quality treatment devices will
improve the local water quality. This improvement is limited to a ’background’
concentration and removal efficiency. That is, there is a point beyond which no
additional treatment of the stormwater quality is possible.
The local treatment devices considered were shown to have an influence on the
regional water quality, but their effectiveness was limited by the untreated subcatchments.
Thus to have an effective influence on the regional water quality, every
sub-catchment within a regional catchment needs to have a local treatment device.
It was demonstrated that a regional treatment device (i.e. a treatment device located at
the catchment outlet) has the greatest influence on the regional catchment
concentration rather than many local treatment devices.
The research demonstrated that in South-East Queensland a treatment device design
for the 3 month ARI storm will not capture up to 90% of the average annual volume.
The aim in the design of treatment devices should be to determine the removal
efficiency required and design a treatment device (or train) to achieve this efficiency.
Unfortunately this is usually limited by constraints such as the ‘background’
concentration level, available space and cost/benefit ratio.<br>Thesis (Masters)<br>Master of Philosophy (MPhil)<br>School of Environmental and Applied Sciences<br>Science, Environment, Engineering and Technology<br>Full Text
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Su, Yuming. "Storm Water Runoff First Flush Modeling and Treatment with a Hydrodynamic Device." Ohio University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1170334793.
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Aboubi, Fadoua. "A cost effective and environmentally friendly stormwater treatment method : The use of wood fly ash and H2O2." Thesis, Linnéuniversitetet, Institutionen för naturvetenskap, NV, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-12204.
Full textAbstract:
This current study is a lab-scale investigation focused on the treatment of stormwater runoff generated in wood-storage areas. The main target constituents of the proposed treatment were: metals (Cu, Cd, Co, V, Pb, Zn, Ni, Cr, Fe, As), COD, TOC, Phenols, and color. The method implemented for this project follows the main concept of using low-cost and environmentally friendly technologies and had as main steps the use of a by-product of wood-based industries - wood fly ashes as sorbents - followed by oxidation with H2O2 (Hydrogen Peroxide). The results obtained during this investigation were vey promising since satisfactory removal % was achieved. Removal rates of 98.5%, 86%, 89.6%, 79.6% were achieved for color, chemical oxygen demand (COD), total organic carbon (TOC) and phenols respectively. Furthermore a decrease in metals concentrations was also observed with the exception of chromium. The study showed that for 300 ml storm water, optimum conditions were with 7g wood fly ash, 5 hours time reaction, pH≈11.46 and 150 μl of a 30% H2O2 solution in a room temperature. To conclude it can be stated that the use of a by-product from wood industry to treat contaminated water from the same sector, following the concept of a closed-loop system, is promising and possible. However further studies need to be conducted in order to evaluate such system in scaled-up conditions.