Dissertations / Theses: 'Biological wastewater treatment'

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Butler, Erick Benjamin. "Biological Treatment of Dietary Supplementary Wastewater." Cleveland State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1264479316.

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Butler, Erick Benjamin. "Biological treatment of dietary supplement wastewater." Cleveland, Ohio : Cleveland State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=csu1264479316.

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Thesis (M.S.)--Cleveland State University, 2009.
Abstract. Title from PDF t.p. (viewed on Feb. 16, 2010). Includes bibliographical references (p. 82-89). Available online via the OhioLINK ETD Center and also available in print.

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Walker, Gavin Michael. "Industrial wastewater treatment using biological activated carbon." Thesis, Queen's University Belfast, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.295433.

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Hou, Xiangting. "DIETARY SUPPLEMENT WASTEWATER TREATMENT BY BIOLOGICAL METHODS." Cleveland State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=csu1326295666.

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Padron, Harold. "Combined anaerobic/aerobic treatment for municipal wastewater." ScholarWorks@UNO, 2004. http://louisdl.louislibraries.org/u?/NOD,110.

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Thesis (M.S.)--University of New Orleans, 2004.
Title from electronic submission form. "A thesis ... in partial fulfillment of the requirements for the degree of Master of Science in the Environmental Engineering Program."--Thesis t.p. Vita. Includes bibliographical references.

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Kang, Young Woon. "Biological treatment of turkey processing wastewater with sand filtration." Columbus, Ohio : Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1078903968.

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Thesis (Ph. D.)--Ohio State University, 2003.
Title from first page of PDF file. Document formatted into pages; contains xxi, 187 p.; also includes graphic (some col.). Includes abstract and vita. Advisor: Karen M. Mancl, Dept. of Food, Agricultural, and Biological Engineering. Includes bibliographical references (p. 169-178).

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Chai, Qian. "Modeling, estimation, and control of biological wastewater treatment plants." Doctoral thesis, Norwegian University of Science and Technology, Department of Engineering Cybernetics, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-2082.

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The activated sludge process (ASP), as the most generally applied biological wastewater purification technique, attracts a great deal of attention from the research community in a highly populated, industrialized world. The main objective of this thesis is to investigate methods for e¢ cient development of activated sludge plant models and for possible improvements in process operation and performance through applications of advanced modeling and control techniques. Different topics in advanced control such as parameter estimation, state estimation, and model predictive control, are addressed, and the methods investigated in this thesis are illustrated with two activated sludge processes, a laboratory-scale nitrogen (N) removal plant and a full-scale phosphorus (P) removal plant: the Duvbacken wastewater treatment plant (WWTP).

As model representation is important in control oriented modeling, the object-oriented modeling approach providing open component-based architectures and reuse of components, is suggested in this thesis to achieve a more flexible model representation. The models of the N-removal process and the Duvbacken WWTP are developed based on the Activated Sludge Models (ASMs) which are generally accepted as the standard models of activated sludge processes (ASPs). The dynamic models are implemented in the object-oriented modeling language Modelica using the Dymola simulation environment, based on a modification of the Modelica library WasteWater. In order to build a good software development environment, special consideration is given to two Dymola interfaces: the Dymola-Matlab interface provided by Dymola and the Dymola-Python interface developed by the author. The application of the modeling approach in this thesis shows that the combination of Modelica/Dymola for efficient object-oriented modeling and Matlab for further analysis is a powerful tool for control system design.

The performances of some widely used state estimation techniques, such as the standard Kalman filter (KF), the extended Kalman filter (EKF), the unscented Kalman filter (UKF), the square-root unscented Kalman filter (SRUKF), and the moving horizon estimation (MHE), are evaluated with application to the N-removal process. The comparison of these filters for the N-removal process shows that the SRUKF improves numerical properties of the UKF and provides the best estimation performance, and the discrete-time EKF gives the fastest performance with a satisfactory estimation result. In addition, since a good characterization of the main compositions in the influent is very important to the performance of the ASM models, a method for simultaneously estimating both model state and influent composition (model disturbance) is developed using the discrete-time EKF and illustrated with the Duvbacken WWTP. The filter has a good convergence property for the observable process based on responses from the simulation model. However, when the filter is evaluated based on the experimental data, the performance of the filter is relatively poor due to unobservability of the system. Additional measurements are therefore needed to render the Duvbacken system locally observable.

Parameter estimation of activated sludge plant models is a challenging task, since the models are in general large-scale, nonlinear, and overparameterized. A procedure for parameter identifiability analysis is discussed and tested with the Duvbacken model. This systematic method proves to be very useful, since it reduces a large number of parameters to a small subset of parameters that can be identified from the available experimental data. The fitting of the model to real data from the industrial plant is not great but satisfactory, especially for those outputs which are important to the plant operation (e.g. concentration of phosphate SPO4 and concentration of total phosphorus TP).

Advanced control strategies for the ASP aeration system are suggested with the focus on the MPC algorithm, since MPC provides an optimization-based procedure with an elegant way of handling constraints and with capabilities of removing process disturbances. Both linear and nonlinear MPC techniques are evaluated with the N-removal process, and the simulation results show that the performances of the MPC controllers are satisfactory: the controllers guarantee that the strict e uent requirements are fulfilled. The nonlinear MPC strategy is also compared with some conventional rule-based controllers, and the MPC controller shows the most reduction of the energy consumption and offers the easiest way to handle the inequality constraints.

Finally, recommendations for future research directions are suggested to an N-removal project group at Telemark University College, Norway.

Paper B reproduced with kind permission of Elsevier

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Aboobakar, Amina. "Quantification of greenhouse gas emissions in biological wastewater treatment." Thesis, Cranfield University, 2014. http://dspace.lib.cranfield.ac.uk/handle/1826/8494.

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There is an increasing need to reduce greenhouse gas (GHG) emissions and to identify influencing factors from wastewater treatment plants (WWTPs), particularly process emissions consisting of nitrous oxide (N2O), and methane (CH4) GHG, with global warming potentials about 310 and 21 times higher than carbon dioxide (CO2) respectively (IPCC, 2006). However, the challenges offered by full-scale environments, have to date, restricted a real-time, comprehensive approach of monitoring emissions and influencing factors. This study aimed at addressing this knowledge gap, by reporting the findings of a long-term, online, continuous monitoring of GHG emissions and operational variables. Lanes were monitored in nitrifying activated sludge plants (ASP) controlled under ammonia (NH4 + ) and dissolved oxygen (DO) set-points (DO setpoints monitored: 1.5 and 2.0 mg/L), as well as in a biological nutrient removal plant (BNR) under NH4 + control. The findings showed that CH4, although potentially formed in non-aerated compartments, was emitted in aerobic zones, at an average emission factor (EF) of 0.07 % of influent and removed chemical oxygen demand (COD). Nitrous oxide EFs on the other hand, depended on relative nitrogen fractions, with influent-based EFs showing a best-case scenario, at 0.05–0.72 % of both influent total nitrogen (TN) and NH4 + , compared to the higher EFs based on removed nitrogen at 0.13–3.9 % of TN and NH4 + removed. The processes operated under the same control settings (DO set-point 1.5 mg/L), had similar, or identical, EF, suggesting that settings could help predict the range of EF. Nitrous oxide was always produced in the presence of NH4 + , even at low concentrations (=<0.5 mg/L), therefore linking N2O production with NH4 + oxidation, particularly with nitrifier nitrification. Incomplete denitrification under low carbon to nitrogen (C/N) ratios also triggered N2O production (EFs of 2.4 and 4.1 % of reduced TN at C/N ratios of 2.8 and 2.4 respectively), particularly with intermittent aeration. Therefore, nitrifier denitrification and incomplete denitrification simultaneously occurred and triggered N2O production in the final stages of nitrification. The BNR lane was the most operationally stable process, therefore offering the best balance between efficiency (60–99 % less aeration and energy per kg of treated NH4 + ), low carbon footprint and reduced EFs (0.08–0.1 % of all nitrogen fractions). The second best option was the DO set-point control of 1.5 mg/L, with low EFs (0.05–0.2 %), stable operational conditions and reduction in aeration requirements (up to 340 % less than DO set-point 2.0 mg/L). Operating ASP under NH4 + control however, led to 7–96 % more efficiency than under DO set-points, although it required better control in the back end of the process. Only an online, long-term methodology such as adopted in this study, could provide insights into emission variability and the effect of operational variables on promoting or reducing emissions. Based on this, strategies to mitigate emissions at full-scale were recommended.

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Coughtrie, Andrew Robert. "Coupling hydrodynamic and biological process models for wastewater treatment." Thesis, University of Leeds, 2016. http://etheses.whiterose.ac.uk/16207/.

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This thesis considers the problem of modelling bioreactors with complex mixing and biokinetic growth based on both soluble nutrients and photosynthesis. From the results of investigations performed on the different modelling methods for nutrient and photosynthesis dependent biomass growth a method of coupling the two biokinetic models was proposed. This new photosynthesis-nutrient (PN) model was then investigated, validated and determined capable of predicting growth characteristics dependent on both nutrient and photosynthetic processes. Additionally an investigation into the factors which may influence the results when using computational fluid dynamics (CFD) to model the flow field within a gas-lift bioreactor was performed. It was determined that one of the main factors which must be considered when modelling bioreactors with boundary layer flow separation is the choice of turbulence model. In the case presented here it was found that the transition SST turbulence model provided the best results with the k-w SST also performing well. Finally, a method of coupling the PN and CFD models was proposed and investigated. The photosynthesis-nutrient-hydrodynamic (PNH) model also incorporated a model for diffusion of light within the bioreactor to allow for investigations into the effects of light absorption and scattering within the bioreactor and how mixing affects the active biomass. Further investigation of this new PNH model determined that the coupling of the biokinetics and flow field provided some insight into the ability of a well-mixed bioreactor to counter low light penetration to an extent.

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Zivich, Jamie Dionne. "Biological Health Assessment of an Industrial Wastewater Treatment Facility." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/43523.

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The biological treatment of wastewaters from an industry was studied. Among the more important wastewater constituents of concern were high levels of suspended solids, due to graphite and nitrocellulose, the solvents, ethanol and acetone, and nitroglycerine (NG). The goal of this project was divided into four objectives. The impacts of graphite on a microbial population were evaluated. Sequencing batch reactors (SBRs) were used to monitor the effects of graphite on mixed liquor suspended solids (MLSS), removal of soluble chemical oxygen demand (sCOD), and specific oxygen uptake rates (sOUR). Graphite appeared to have no adverse effect on the microbes. The potential benefits of adding sucrose, nitrogen, and phosphorus to SBRs were evaluated. The MLSS was maintained at 1,250 mg/L, similar to the microbial population in the suspended growth system at the industry. Sucrose addition increased the sCOD removals and sOUR. No direct effect was observed with the addition of nitrogen and phosphorus. The treatability of acetone and ethanol was studied through sOUR and batch testing to determine bacterial response to solvents. Both solvents were utilized by the microbes. The concentrations tested proved to be beneficial, not inhibitory. Ethanol and a 50/50 mixture of acetone and ethanol were more viable substrates than acetone. NG treatability was examined under anoxic and aerobic conditions in SBRs and batch biological reactors. NG degradation occurred under anoxic conditions, but was more favorable in aerobic environments. NG was degraded in all SBR tests to below detection limit (0.5 mg/L); therefore, the optimal treatment could not be determined.
Master of Science

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11

Bi, Tianzhu. "Biological Treatment of Milk and Soybean Wastewater with Bioproducts." Cleveland State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=csu1292017443.

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Liu, Hong, and 劉紅. "Bio-hydrogen production from carbohydrate-containing wastewater." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31244518.

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Lumbers, Jeremy. "Rotating biological contactors : mechanisms, modelling and design." Thesis, Imperial College London, 1988. http://hdl.handle.net/10044/1/47161.

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Li, Wen. "Improvement of Biological Processes of Inland Municipal Wastewater Treatment Plant." Thesis, KTH, Mark- och vattenteknik, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-190742.

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This master thesis gives an account for various aeration schemes that are utilized in conventional activated sludge treatment process in a wastewater treatment plant. By altering between different aeration schemes, the project aimed at reducing energy consumption along with maintaining the treatment performance at the plant. A series of experiments on the treatment performance over several different aeration schemes thus has been conducted on site at Solviken in Mora, Sweden. The project is basically a case study where no parameters were manually controlled except for the aeration schemes at the plant. Energy consumption reduction is logically relative to the ratio between aeration and non-aeration intervals. Several criteria were tested in regards to the treatment performance, including pH value, organic matters, phosphorus substances and microorganisms. The study has come up with a superior aeration scheme for the plant, as well as indicated processes that can be improved at the plant.

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Kent, Tanya Denise. "The effect of media size on biological aerated filter performance." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.287176.

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Berktay, Ali. "The effects of pressure on aerobic biological wastewater treatment using rotating biological contractors." Thesis, Loughborough University, 1993. https://dspace.lboro.ac.uk/2134/11709.

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The aim of this research was to investigate the application and effects of pressure on an aerobic biological wastewater treatment process. For the purpose of the investigation two specially designed, identical, laboratory-scale rotating biological contactor (RBC) units were constructed. One of these was held in a steel pressure vessel while the reference unit was operated open to the atmosphere. The treatment capabilities of the pressurized unit, as compared to those of the reference unit, were determined for a variety of organic loadings at increasing pressures up to a limit of 6 bar. During the investigation, the substrate employed was a synthetic wastewater made up frequently in the laboratory. Most of the analytical work was carried out on composite druly samples of the feed wastewater and of the two effluents produced, both filtered and nonfiltered. In addition, sludge samples from both units were regularly tested for a variety of sludge parameters. The water quality parameters investigated were the 5-day Biochemical Oxygen Demand (BOD5), the Chemical Oxygen Demand (COD), Suspended Solids, pH, Temperature, Ammoniacal Nitrogen and Total Oxidized Nitrogen (TON). The yield of sludge produced and certain characteristics of sludge i.e. Specific Stirred Volume Index (SSVl). Specific Resistance to Filtration, were also obtained. The quantity of air required for the pressurized treatment unit was also investigated. The pressurized treatment unit has demonstrated the capability of operating with a high level of carbonaceous oxidation and nitrification at organic loadings of up to 13 g BOD5/ m2 of disc area per day. In comparison with the identical reference unit operated at atmospheric pressure, the pressurized unit demonstrated slightly improved BODs and COD removal efficiencies, a greatly improved level of nitrification and a substantially lower sludge production. All these characteristics improved with increasing pressure.Of particular importance the sludge yield coefficient was always significantly lower for the pressurized unit than for the reference unit and results such as 0.12 kg dry solids/ kg BOD5 removed at 6 bar pressure are highly signif1cant with regard to the requirements of the modern wastewater treatment industry. Additional investigations were carried out to determine the cost of a proposed full-scale pressurized treatment unit with a design based upon the findings of this investigation. These were compared with the costs of a conventional biological treatment process capable of treating an equivalent wastewater loading. The comparison between the pressurized unit and the selected processes were made for three populations (500, 1,000 and 3,000 persons). The sludge disposal costs of the pressurized unit were appreciably lower than those for the other processes. The results indicated that the cost of the pressurized unit (present value for a twenty-year period) and the costs of activated sludge and conventional RBC processes were found to be similar for the smaller populations. However a substantial saving could be obtained with the pressurized unit for the larger populations. In addition there is an indication that the land requirement of the pressurized treatment unit decreases appreciably as the flow rate increases.

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Mendoza, Espinosa Leopoldo Guillermo. "Upflow and downflow biological aerated filters (BAFs) for wastewater treatment." Thesis, Cranfield University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.268131.

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Uttley, P. J. "Integration of biological wastewater treatment and algal growth for biofuels." Thesis, University of Sheffield, 2014. http://etheses.whiterose.ac.uk/6393/.

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This thesis is concerned with the production of biofuels from microalgae that can be grown in wastewater on marginal land. Algal-derived biodiesel is a promising alternative to both the finite reserves of fossil fuels and also the current biofuel crops that take up agricultural land. The case for coupling biological wastewater treatment to the production of algal biodiesel is a compelling one that is explored in this research using a combination of mathematical modelling and laboratory experiments. Algae utilise by-products of the wastewater treatment process such as carbon dioxide, nitrate and ammonia. In this work, a mathematical model of an integrated wastewater treatment and algal cultivation system is presented. The model contains two units: an activated sludge unit for secondary wastewater treatment and a pond for the cultivation of algae. These units have both liquid phase and gas phase integration. For the liquid phase, the treated effluent from the activated sludge unit is transferred to the algal pond to provide nutrients for algal growth. The model also incorporates gas-phase integration whereby the CO2 rich off-gas from the activated sludge unit is captured and used to enhance the algal growth. In addition, the O2 enriched off-gas from the algal pond is recycled back to improve dissolved oxygen levels in the activated sludge unit. The mathematical model uses equations for algal growth that were developed using laboratory experiments to measure the effect of dissolved CO2, nitrate and ammonia on the growth kinetics of a typical strain of freshwater alga: Chlorella sp. The model includes the industry standard Activated Sludge Model No. 3 for wastewater treatment. An economic profit function is used in the model to find the optimal pattern of gas phase integration to maximise Net Present Value over a specified project lifetime. For the case considered, the model predicts that integration using the gas and liquid exchange described above is necessary for a profitable outcome. This is a general approach that can be used to retrofit biofuel production onto an existing wastewater site, or design a new integrated system from first principles.

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Hodges, Alan J. "Alternative Treatment Technologies for Low-Cost Industrial and Municipal Wastewater Management." DigitalCommons@USU, 2017. https://digitalcommons.usu.edu/etd/5884.

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Roughly the same volume of water that rushes over the Niagara Falls is produced as wastewater in North America. This wastewater is treated through a variety of means to ensure that it can be safely returned to the natural ecosystem. This thesis examines two novel means for this treatment, one biological and one physical-chemical in nature, namely, Rotating Algae Biofilm Reactor treatment and expanded shale augmented coagulation-flocculation. Rotating algae biofilm reactors (RABRs) support biofilm algae growth, and in turn, the algae take up harmful contaminants from the wastewater. This system was tested in wastewater from petroleum refining operations. The efficacy of the RABR system was compared with a traditional method of wastewater treatment, open pond lagoons, where wastewater is open to sunlight and algae growth occurs in suspension as compared to the biofilm formed by the RABR system. The RABR treatment demonstrated a statistically significant increase in removal of three constituents in wastewater that are harmful to the environment: nitrogen, phosphorus, and suspended solids. Additionally, the RABR treatment demonstrated increased biomass production. This biomass can be converted into a variety of bioproducts including biofuels, agricultural feed, and nutraceuticals. This study is the first demonstration of this system in petroleum refining wastewater. Currently, many wastewater treatment facilities use coagulation-flocculation to remove suspended solids from the wastewater. To achieve this removal, coagulants are added to the wastewater, which removes surface charges of the suspended particles, allowing particles in solution to coalesce and settle by gravity out of solution. One common coagulant added to wastewater is ferric sulfate. This study demonstrated that the addition of a new compound, expanded shale, to ferric sulfate could greatly improve the efficacy of the existing ferric sulfate coagulation system.

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Amini-Rad, Hassan. "An experimental study of air scour in biological treatment." Thesis, Queen's University Belfast, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336735.

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Tjernström, Linnéa. "Function of soil-based on-site wastewater treatment systems - Biological and chemical treatment capacity." Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-210716.

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On-site wastewater treatment systems are among the main Swedish anthropogenic sources of nutrients causing euthropication of the Baltic Sea. Among on-site systems in Sweden almost half have septic tank treatment followed by a soil-based system, in which the wastewater is treated through soil filtration. In this study a soil based technique for on-site wastewater treatment is studied where wastewater is filtered through a sand filter. Composite samples of influent and effluent at two sand filters in the area of Stockholm are sampled to determine their chemical and biological function and to compare their treatment capacity to requirements. Parameters within the scope of the study are tot-P, NH4-N, DOC, pH, turbidity and dissolved oxygen. Biological function was considered to be good in both systems as nitrification was high and the effluent had sufficient levels of dissolved oxygen suggesting aerobic conditions. Prevailing aerobic conditions in the sand filters would also indicate good reduction of organic substances which is the case for DOC as it was reduced by above 85 % for one site and almost 70 % for the other site. The overall high reduction of organic micropollutants in the systems, reported in another study, also suggests that biological function when it comes to reduction of organic substances is good. On the other hand, chemical function, with respect to reduction of phosphorus, was not sufficient as none of the systems fulfilled the requirements from HaV for normal or high protection level. In the systems tot-P was reduced by 42 and 54 % respectively. A drawback with the method approach used in the study is that the obtained reduction results only can represent the actual situation if variations in incoming and outgoing flow, variations in influent concentrations and magnitude of dilution of effluent compared to daily wastewater load are small. As these are unknown in this case it adds uncertainty to the results.
Decentraliserade system för rening av avloppsvatten är bland de huvudsakliga svenska antropogena källorna till näringsämnen som bidrar till övergödning av Östersjön. Bland decentraliserade system i Sverige är nästan hälften system med slamavskiljare följt av ett markbaserat system i vilket avloppsvattnet renas genom infiltration i jord. I denna studie studeras en markbaserad teknik i vilken avloppsvattnet filtreras genom sand, en så kallad markbädd. En fältundersökning gjordes där samlingsprov av ingående och utgående avloppsvatten togs på två markbäddar i Stockholmsområdet för att bestämma deras biologiska och kemiska reningsfunktion samt att jämföra avskiljningen av fosfor i systemen med rekommendationer från HaV. Parametrar som inkluderats i studien är totalfosfor, ammonium-kväve, löst organiskt kol, pH, turbiditet och löst syre. Biologisk funktion ansågs bra i båda markbäddarna eftersom nitrifikationen var hög och utgående vatten hade tillräckliga halter av löst syre vilket implicerar att markbäddarna var väl syresatta. Rådande syrerika förhållanden i markbäddarna antyder också att organiskt material bryts ned avsevärt, vilket är fallet för löst kol som reducerades med mer än 85 % i en av markbäddarna och med nästan 70 % i den andra. Den höga reduktionen av organiska mikroföroreningar som påvisats i markbäddarna i en annan studie tyder också på att biologisk funktion med avseende på avsklijning av organiska substanser är bra. Kemisk funktion, med avseende på avskiljning av totalfosfor, var inte tillräcklig då ingen av markbäddarna levde upp till reduktionskraven från HaV för normal eller hög skyddsnivå. Totalfosfor avskiljdes med 42 respektive 54 % i markbäddarna. En nackdel med metoden som användes i studien är att de resultat som fåtts för avkiljning av de olika parametrarna endast kan representera den verkliga situationen om variationer i in- och utgående flöde samt variationer i ingående vattenkoncentrationer är små och om utspädningseffekten av utgående vatten är försumbar.

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Basu, Pradipta Ranjan. "Evaluation of biological treatment for the degradation of petroleum hydrocarbons in a wastewater treatment plant." Texas A&M University, 2005. http://hdl.handle.net/1969.1/2418.

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Biodegradation of petroleum hydrocarbon can be an effective treatment method applied to control oil pollution in both fresh water and marine environments. Hydrocarbon degraders, both indigenous and exogenous, are responsible for utilizing petroleum hydrocarbon as their substrate for growth and energy, thereby degrading them. Biodegradation of hydrocarbons is often enhanced by bioaugmentation and biostimulation depending on the contaminated environment and the competence of the hydrocarbon degraders present. An evaluation of the performance of the biological treatment of petroleum hydrocarbon by the hydrocarbon degrading microbes at the Brayton Fire School??s 4 million gallon per day (MGD) wastewater treatment plant was the main research objective. Samples were taken for two seasons, winter (Nov 03 ?? Jan 03) and summer (Jun 04 ?? Aug 04), from each of the four treatment units: the inlet tank, equalization tank, aeration tank and the outfall tank. The population of aliphatic hydrocarbon degraders were enumerated and nutrient availability in the system were used to evaluate the effectiveness of on-going bioaugmentation and biostimulation. Monitoring of general effluent parameters was conducted to evaluate the treatment plant??s removal efficiency and to determine if effluent discharge was in compliance with the TCEQ permit. The aeration tank is an activated sludge system with no recycling. Hydrocarbon degraders are supplied at a constant rate with additional nutrient supplement. There was a significant decrease in the population of microbes that was originally fed to the system and the quantity resident in the aeration tank. Nutrient levels in the aeration tank were insufficient for the concentration of hydrocarbon degraders, even after the application of dog food as a biostimulant. The use of dog food is not recommended as a nutrient supplement. Adding dog food increases the nitrogen and phosphorus concentration in the aeration tank but the amount of carbon being added with the dog food increases the total chemical oxygen demand (COD) and biochemical oxygen demand (BOD). An increase in the concentration of total COD and BOD further increases the nitrogen and phosphorus requirement in the system. The main objective of supplying adequate nutrients to the hydrocarbon degraders would never be achieved as there would be an additional demand of nutrients to degrade the added carbon source. This research study was conducted to identify the drawbacks in the treatment plant which needs further investigation to improve efficiency.

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Yan, Qingmei, and 嚴慶梅. "Biological nitrogen removal of saline wastewater by ammoniumoxidizers." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42182116.

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Bengtsson, Erica, and Sannam Hjertstrand. "Hybrid system for wastewater treatment in multifunctional wetlands - A case study at UNIVATES in Lajeado, RS, Brazil." Thesis, Halmstad University, School of Business and Engineering (SET), 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-1604.

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Abstract

Centro Universitaire UNIVATES is located in the town Lajeado that is situated in the most southerly state, Rio Grande Do Sul, in Brazil. The university has 5000 students, teachers and others staff. UNIVATES is not satisfied with their present wastewater situation and wants to improve it by eliminate the smell caused by the wastewater. They would also like to remove the oil that the storm water brings into the wetland. The high amount of particles in the storm water gives rise to a lot of sediments that eventually will fill up the wetland, and something has to be done about this, if the wetland should continue to be in use. Another aspect to consider is the wish of some people at UNIVATES, for the wetland to be a beautiful and recreational place. All these factors had to be considered, which led to the main question: How can the use of the wetland for wastewater treatment be combined with the request for the wetland to be a beautiful place with the wildlife preserved?

During the course Wetland Technology that we took before our departure to Brazil, we got introduced to the situation at UNIVATES by Professor André Jasper and Odorico Konrad who visited the course several times. They pointed out that the main issue is the smell from the wastewater and later during the field study at UNIVATES, more information were obtained through discussions, meetings and conversations with the people involved. Several visual inspections were carried out by walking around the wetland. We could determine where and how the inlets and outlets to the wetland were and when it was clear which inlets that brought wastewater and which that brought storm water, the water flow of the wastewater was estimated. Water samples from the wetland were collected at five different sites and analyses of pH, BOD, COD, N-Tot, phosphorus and metals were done by the accredited laboratory at UNIVATES. To test some of our theories, we did a smaller practical experiment that got the name Superficial Filtration Bed.

The results from the water samples showed the highest BOD, COD, N-Tot and Phosphorus levels in the samples from site 2 and 4 and this reveals that it is wastewater. This was also confirmed by the smell that we felt at these sites during the visual inspections. The results also showed that there is no wastewater coming from site 1, 3 and 5.

Our final proposal is to create a multifunctional wetland with the purpose to take care of both storm water and wastewater and at the same time work as a research and recreational area. The wetland, which would be divided into two parts, will constitute of all the fundamental functions; storm water buffering, sedimentation basin and biological oil separation and treatment. There will also be research sites and hybrid system for wastewater treatment. The hybrid system will consist of two steps where the first is aerobic and the second both aerobic and anaerobic. The first step is a Superficial Filtration Bed (SFB) and the second a FWS wetland.

The conclusion of this thesis is that more detailed research is needed to be able to dimension the specific functions correctly. With some further investigations the proposal presented is possible to carry through and our feeling when we left UNIVATES was that the people responsible really liked our ideas. They made it clear that they want to make a change and improve the situation and with the help they have gotten from us, they are a few steps closer to solving the problem.

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Ng, Chi Po. "Treatment of textile wastewater by combined photo-fenton and biological process /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?EVNG%202005%20NG.

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Tipadis, Grigoris G. "Mathematical models for wastewater treatment by the Rotating Biological Contactor process." Thesis, Imperial College London, 1991. http://hdl.handle.net/10044/1/8514.

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Mathys, Renata Gabriela. "Aerobic treatment of a CTMP wastewater using a rotating biological contactor." Thesis, University of British Columbia, 1991. http://hdl.handle.net/2429/30025.

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Effluents from high-yield TMP and CTMP mills contain biochemical oxygen demand and toxicity levels that are much higher than the effluents from low-yield kraft mills and if not properly treated before disposal can impose environmental threats to water bodies. Therefore, this study was undertaken to demonstrate the ability of a rotating biological contactor to remove organic matter from such a CTMP wastewater when operated at different flowrates and temperatures. An apparatus was constructed to allow for temperature control of the wastewater and the flexibility to change flowrates and disc rotational speed. Parameters studied included BOD₅, COD, suspended solids, dissolved oxygen, sulfur compounds, acetic acid and nutrient uptake. Because the lab device exposes a thin film of liquid to the air over an extensive surface, evaporation from the RBC as high as 87% at temperatures of ~ 30°C were experienced during the experiment. Results of this study showed that for hydraulic residence times (HRT) of 1 to 2 days the BOD₅ removal ranged from 77 to 86% with a corresponding COD removal of 63 to 72%. Increases in flowrate (decreases in HRT) resulted in a slight decrease in percent BOD (COD) removed and an increase in loading rate and BOD (COD) removal rate. An increase in temperature from 20 to 30°C increased BOD removal from 70.1 to 85% and COD removal from 45.8 to 71.4% at HRT=1.5 days. Dissolved oxygen, pH and MLVSS had no distinct effects on the removal of BOD₅ and COD. Losses due to evaporation of major volatile compounds tested were minimal at the pH of operation. Start-up time of the RBC was of the order of 1 day during the experiment. An attempt to do a run without microorganism activity by adding 50 mg/1 HgCl₂ failed to eliminate all the organisms present in the wastewater and RBC. Tracer studies revealed that the RBC was close to being perfectly mixed.
Applied Science, Faculty of
Chemical and Biological Engineering, Department of
Graduate

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28

Zhang, Qiuzi. "Kinetic formulations for growth and substrate uptake in biological wastewater treatment." Thesis, University of Ottawa (Canada), 2009. http://hdl.handle.net/10393/28361.

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The Monod or hyperbolic kinetic formulation became the de facto kinetic descriptor in activated sludge models in the '80s-'90s. It still plays a prominent role in activated sludge models; however, a dual hyperbolic formulation (with respect to both substrate and active biomass) that implicitly accommodates storage as well as more rationally describes metabolic kinetics is more prominent in governing metabolic functions in activated sludge models (ASMs) promulgated by working groups under the aegis of the International Water Association (IWA). There are other kinetic formulations used in the models of this group as well as models of the activated sludge process formulated by others. There is lack of consistency in the choice of kinetic formulations for various processes even within the IWA family of models. This thesis examined the basis for the common Monod and dual-hyperbolic formulations and puts forward theoretical justifications of them based on various considerations of mass transfer, storage and metabolic rate formulation. Other models were developed based on major governing principles. Models used in biological wastewater treatment are Eulerian gross descriptors of a process involving mass transfer, many substrates, and metabolic pathways and their enzymes, contained within many microorganisms. Any model at this level is merely a fit of mathematical formulations to data. As number of processes in biotreatment models increases along with mathematical descriptors and their associated coefficients, fitting an overall model improves to a point. But beyond this there has been little justification of the Monod or other kinetic expressions. Since a variety of formulations have been proposed for two of the primary metabolic processes which are hydrolysis of complex substrates and then metabolism of resulting readily degradable (or simple) substrates, the primary objective of this study was to examine these processes by experiment and determine the most appropriate models for each step. A chemostat was used in this study to culture active biomass acclimatized to a feed containing starch, a complex substrate requiring hydrolysis, and glucose which is readily biodegradable and also a product of starch hydrolysis. Active mass samples were taken from the chemostat and placed in batch reactors where varying concentrations of active mass were exposed to varying concentrations of either glucose or starch. Before adding any substrate to the batch reactors the active mass was aerated for a period of time until DO change was not observed to ensure that any stored or extraneous substrate was metabolized. After addition of one or the other substrate, the rate of dissolved oxygen (DO) uptake was monitored over the initial 15 minutes in the batch culture. Rapidly changing conditions dictated the necessity of using DO as a surrogate for either starch or glucose. Over 249 models were examined for their ability to describe glucose metabolism for 16 different batch experiments. The Monod model gave a good fit to the data. Other models that were equally applicable were too complex or made no scientific sense. Another series of batch tests were conducted using only starch as a substrate. Again substrate concentration and active mass concentration were varied in the batch tests in six different batch runs. The results from these experiments were again used to determine the adequacy of 249 starch hydrolysis models. The Monod type relationship and a dual hyperbolic relation again proved to be the most reasonable choices. Also a first-order model based on starch concentration was applicable. However no general set of coefficients that applied to all experiments was found for any model; it is necessary to calibrate either model to environmental conditions. All of these models are fairly simple in terms of concept as well as determination of parameters and have scientific sensibility in describing hydrolysis of SBCOD. Keywords: wastewater, activated sludge, dissolved oxygen, modeling

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29

Chan, Yue-ping, and 陳裕萍. "Simulation and analysis of biological wastewater treatment processes using GPS-X." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2003. http://hub.hku.hk/bib/B31255437.

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Li, Yun, and 李贇. "Formation and stability of aerobic granular sludge in biological wastewater treatment." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/197519.

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Aerobic sludge granulation is a new technology that has been developed for biological wastewater treatment. Compared with conventional activated sludge, aerobic granules allow better sludge-water separation and a higher biomass concentration. However, the mechanism of the transformation from sludge flocs to granular sludge under the aerobic condition is still unclear. Deterioration of aerobic granules in long-term operation is also a concern for its scale-up application. The present study was conducted to investigate the crucial factors for aerobic granulation and its underlying mechanism. In addition, the stability of aerobic granules under unfavorable conditions and the recovery of deteriorated granules in bioreactors were also studied. For formation of aerobic granules, gelation-facilitated biofilm growth was proposed as a new mechanism for the granulation process. Simulation of granule formation was performed in a well-controlled chemical system to provide an experimental proof for the proposed aerobic granulation theory. Granule formation was achieved in a particle suspension with latex microspheres for bacterial cells and alginate and peptone for extracellular polymeric substances (EPS), together with the cation addition and floc discharge. In the mixture with the dosing of alginate and a small amount of peptone, artificial gels and granules could be well formed, and the artificial granules share the similar micro-structure as the aerobic bacterial granules. However, as the dose of peptone increased, gels were not formed and only large particle flocs were produced. The formation of artificial granules proves that effective EPS interactions with cations and the subsequent gelation are crucial to aerobic granulation in bioreactors. In relation to granulation, the effect of the substrate feeding pattern on the microbial yield was tested. The results show that the bioreactor with a more frequent substrate feeding interval had a lower sludge yield than the reactor (0.45 vs. 0.55) with a less frequent feeding. The sludge fed less frequently was able to store more substrates as intracellular substances, resulting in more biomass growth. Moreover, a long feeding interval would force the biomass into the feast-famine regime, which was found to enhance microbial growth and granulation, producing granules with a compact and stable structure. For the stability of aerobic granules, various factors that would been countered in biological wastewater treatment were experimented. The results show that granules deteriorated in structure under unfavorable conditions, such as a low solution pH (pH~6.0), a high loading rate, and feed of starch instead of glucose into the bioreactors. In some deterioration cases, filamentous bacterial growth became more dominant and the granules became loose and fluffy flocs. Compared to mature granules, fresh granules were less stable and more vulnerable to the unfavorable conditions. As the granules deteriorated in structure, their surface roughness values increased considerably from 35 or less to more than 230. Under a favorable condition with a feed of sodium acetate, the deteriorated granules could be recovered in some reactors. However, deterioration of the granules caused by filamentous growth at a low pH or high loading rate could hardly be recovered.
published_or_final_version
Civil Engineering
Master
Master of Philosophy

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31

Buck, Andrew. "Characterisation of chemical processes operating within a biological wastewater treatment plant." Thesis, Open University, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.409874.

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Holtman, Gareth Alistair. "Design, installation, and assessment of a biological winery wastewater treatment system." Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2573.

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Thesis (MTech (Civil Engineering))--Cape Peninsula University of Technology, 2017.
Currently in South Africa, most wastewater from small cellars is pH-adjusted and disposed of via land irrigation. This practice can lead to environmental degradation. There is a need for low cost, low maintenance solutions for the treatment of cellar effluent. Constructed wetlands provide such an option. However, the use of plants is problematic because winery effluent can be phytotoxic. After successful initial laboratory-scale experiments, an in-situ pilot scale biological sand filter (unplanted constructed wetland) system was designed, installed, and used to treat effluent from a small winery in the Western Cape, South Africa. The system is off-grid, totally self-regulating, and uses a modular approach which allows for the addition and subtraction of filter modules within the system to alter treatment capacity, retention time and/or rest filter modules. The system can be easily integrated into existing settling basins and/or retention ponds at small wineries. The biological sand filter was operational for 610 days, and showed promising results. The average chemical oxygen demand removal efficiency was 81% (range: 44-98%) with an average effluent of 324 mg/L, and an average flow rate of 413 L/day after the acclimation (start-up) period. The average hydraulic loading rate after the initial start-up period was 143 L/m3 sand day-1 (range: 67-222/m3 sand day-1), with an organic loading rate of 205 gCOD/m3 of sand day-1 (range: 83-338 gCOD/m3 sand day-1) which resulted in an organic removal rate of 164 gCOD/m3 of sand day-1. There was an average of 67% removal of total phenolics, thereby reducing the potential phytotoxicity of the effluent. In addition, there was a 1.6 times increase in calcium concentration, a 29% decrease in the average sodium adsorption ratio, and complete passive neutralisation of the acidic winery wastewater (final effluent pH range: 6.63 – 8.14. The findings of this study compare well with previous laboratory studies conducted with synthetic and authentic winery effluent. The system can potentially provide a low cost, energy efficient, low maintenance, sustainable means of treating cellar effluent at small wineries. Uptake of this technology may alleviate environmental degradation caused by irrigating land with inadequately treated effluent.

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Yi, Taewoo Harper Willie F. "Sorption and biodegradation of pharmaceutical compounds in biological wastewater treatment process." Auburn, Ala., 2007. http://hdl.handle.net/10415/1335.

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34

Opdycke, Mary Ellen. "Physicochemical and biological treatment of a textile dyeing and finishing wastewater." Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-01312009-063352/.

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35

Fica, Zachary. "Pairing of Anaerobic and Aerobic Treatment of Petroleum Wastewater." DigitalCommons@USU, 2017. http://digitalcommons.usu.edu/etd/6832.

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The objective of this project was to treat petroleum refinery wastewater using a combination of anaerobic and aerobic processes, namely an Up-flow Anaerobic Sludge Blanket (UASB) reactor paired with a Rotation Algae Biofilm Reactor (RABR), respectively, to produce a treated effluent. The treatment method developed needed to produce a cost-effective and efficient way to decrease nitrogen, phosphorous, total suspended solids (TSS), and COD concentrations to below State of Utah limitations. It was demonstrated that RABR treatment was capable of reducing effluent concentrations of nitrogen, phosphorus, and TSS to State of Utah limitations. RABR treatment did not significantly reduce COD from the wastewater. The COD reduction requirement, however, was met through anaerobic digestion of the wastewater. Therefore, our system proved effectual at the treatment of the wastewater and met all design criteria.

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36

Mann, Allan. "A comparison of floating and sunken media biological aerated filters (BAF)." Thesis, Cranfield University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.359948.

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37

Gamez, Grijalva Victor Manuel. "BIOLOGICAL AND PHYSICAL-CHEMICAL METHODS FOR TREATMENT OF SEMICONDUCTOR MANUFACTURING EFFLUENTS." Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/195838.

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Semiconductor manufacturing is one of the most advancing, growing and evolving industries. The production of semiconductors presents several challenges, both technologically and environmentally. The amount and complexity of the chemical substances utilized in the manufacturing process has been growing exponentially, and new chemicals are often introduced to the process and the environment. Two steps of this process play a special important role in the introduction of new chemical and demand of natural resources: Chemical Mechanical Planarization (CMP) and Photolithography.Wastewaters from the semiconductor manufacturing are complex and have several chemicals in different concentrations. Heavy metals, acids, chelators, surfactants and other chemicals are found in semiconductor effluents. Part of the scope of this study is to evaluate and remediate wastewaters produced in semiconductor manufacturing.During the development of this project it was found that copper can be successfully removed and recovered from CMP wastewaters by the use of a sulfate reducing bioreactor and a crystallization reactor, promoting precipitation of copper sulfides on the surface of silica sand. High removal and recovery efficiencies were found as result of the study. Another finding include that citrate is a readily biodegradable compound which can be successfully utilized as electron donor for anaerobic processes such as methanogenesis and sulfate reductions. However other important chelator, like EDTA, can cause toxicity to these microorganisms and affect important biological processes. PFOS is an important chemical for the semiconductor industry; however, the physical and chemical properties make this compound persistent in the environment and bioaccumulative. New substitutes for PFOS were tested and evaluated for their environmental impact. It was found that perfluorination plays an important role in the chemical properties of PFOS and removal of this characteristic improves the environmental performance of the new substitutes. Evaluation of these new chemicals was also performed by simulation and modeling. The software utilized in this study identified properties like toxicity and octanol-water partition coefficient accurately. On the other hand biodegradability was poorly estimated and new models are suggested for evaluation of this property for compounds with characteristics similar to the ones studied here (specifically high fluorination).

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Kuhn, David Dwight. "Enhancing Aquaculture Sustainability Through Water Reuse and Biological Treatment." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/26723.

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Overfishing of natural fisheries is a global issue that is becoming more urgent as the human population increases exponentially. According to the Food and Agriculture Organization of the United Nations, over 70% of the worldâ s seafood species are fully exploited or depleted. This high demand for seafood protein is not going away; and, in fact, an astonishing one out of five people in this world depend on this source of protein. Traditional aquaculture practices use pond and flow-through systems which are often responsible for discharging pollutants into the environment. Furthermore, aquacultural feeds often contain high levels of fish protein, so the demand on wild fisheries is not completely eased. Even though traditional aquaculture has these drawbacks, there is a significant movement towards more sustainable practices. For example, implementing recirculating aquaculture systems (RAS) maximizes the reuse of culture water which decreases water demand and minimizes the levels of pollutants being discharged to the environment. And, alternative proteins (e.g., soy bean) are replacing the fish and seafood proteins in aquaculture diets. Accordingly, the research described in this dissertation focused on maximizing the reuse of freshwater fish effluent to culture marine shrimp. More specifically, by using suspended-growth biological reactors to treat a tilapia effluent waste stream and to generate microbial flocs that could be used to support shrimp culture. This RAS technology will decrease water consumption by increasing the amount of recycled water and will also improve effluent water quality. The biomass generated in the bioreactors could be used to feed shrimp with an alternative source of protein. Treating fish effluent to be reused to culture shrimp while producing this alternative feed, could significantly decrease operational costs and make these operations more sustainable. Understanding which ions are critical for the survival and normal growth of marine shrimp in freshwater effluents is essential. It is also very important to understand how to convert an effluentâ s organic matter into food for shrimp. Results from studies revealed that the marine shrimp, Litopenaeus vannamei, can be raised in freshwater effluent when supplemented with specific ions and wet microbial flocs fed directly to shrimp can enhance growth in shrimp fed a restricted ration of commercial feed. The treatability of the tilapia effluent using suspended-growth, biological reactors and nutritional analysis of the generated biomass were also reported. Carbon supplementation enhanced reactor performance and microbial floc generation. These microbial flocs also proved to be a superior feed ingredient when dried and incorporated into a pellet feed.
Ph. D.

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39

Sudarjanto, Gatut. "Integrated chemical and biological treatment process to remove colour compounds from wastewater /." [St. Lucia, Qld.], 2006. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe19717.pdf.

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40

Kramadhati, Narahari Narasiah. "The impact of aircraft deicing wastes on the biological wastewater treatment process /." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100640.

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In order to ensure aircraft safety during winter conditions, glycol-based deicing and anti-icing fluids are employed prior to takeoff. These products can exert a severe impact on the environment if allowed to go untreated. The present study is related to the treatment of glycol-contaminated wastewaters by the activated sludge process.
The specific objectives of the research were to: (1) determine the effects of process parameters such as biomass concentration, deicing fluid concentration and temperature on the biodegradation kinetics. (2) determine the mechanism of deicing fluid removal and model the reaction rates. (3) determine the effects of microbial changes on the treatment process. (4) evaluate the advantages of a sequencing batch reactor for the treatment of deicing wastes. (5) corroborate our laboratory results with field data from an operating wastewater facility treating deicing wastes.
The results from the field show that despite the increases in influent organic matter during the deicing season, there were very little changes in effluent values of organic matter. Furthermore, influent concentrations of deicing fluid between 10 and 30 mg/L were reduced to trace amounts (i.e. below 5 mg/L) throughout the deicing season. However, as witnessed by the high sludge volume index during the deicing season, the presence of deicing fluid creates settling problems in the clarifier.
The laboratory batch experiments indicate optimal substrate removal rates at biomass concentrations of 1000 mg/L and 2000 mg/L. Very low biomass levels lead to inhibition whereas a high biomass level of 3000 mg/L is unnecessary since the food to microorganism ratio is such that only a fraction of the biomass participates in the degradation reaction. With regards to deicing fluid concentration, organic matter removal rates tend to increase as the deicing fluid is increased. However, at the highest level of deicing fluid, certain inhibitory effects are present. As expected, higher temperatures produce much higher removal rates with the ethylene glycol substrate showing less variation with temperature than the other organic compounds present in the wastewater.
With regards to the mechanism of removal, the results showed very little adsorption of organic matter onto the biomass within the first hour of contact. In addition, the total organic matter removal (TOC and COD) followed first order kinetics with respect to substrate concentration.
Lastly, sequencing batch reactor operation allowed for much higher removal rates as the microbial population is acclimatized to the substrate with increasing cycles. With regards to the microbial population, the Biolog results showed that there was a decrease in the variety of compounds that could be degraded as the biomass was exposed to the deicing fluid. Furthermore, most population changes occurred at the very beginning of the deicing season and in the first half of the SBR experiments.

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41

Cameron, Kimberley A. "The efficiency and mechanisms for pollutant removal in biological wastewater treatment systems /." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33724.

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The research project was initiated to refine the knowledge available on the treatment of rural municipal wastewater by constructed wetlands. Field and laboratory studies were conducted to determine the treatment capacity of a constructed wetland system and to determine a substrate that would be most efficient as a phosphorus adsorption filter. The wetland system consisted of three free-water surface cells, three blast furnace slag filters and a vegetated filter strip, treating municipal wastewater. Bimonthly water samples at the inlet and outlet of each component of the wetland system were analysed for biochemical oxygen demand, nitrate and nitrite, ammonia and ammonium, total Kjeldahl nitrogen, total suspended solids, total phosphorus, ortho-phosphate, fecal coliforms and E. coli. Phosphorus and nitrogen concentrations were determined in the sediment, plant tissue and water column of the free-surface wetland cells. The free-surface wetland cells achieved removals as follows: ammonia and ammonium (52%), total Kjeldahl nitrogen (37%), total suspended solids (93%), total phosphorus (90%) and ortho-phosphate (82%). The vegetated filter strip achieved removals as follows: ammonia and ammonium (28%), total Kjeldahl nitrogen (11%), total suspended solids (22%), total phosphorus (5%) and ortho-phosphate (0%). The slag filters reduced total phosphorus by more than 99%. Phosphorus adsorption measurements were conducted on slag, calcite and shale. Slag was found to be the most effective at removing phosphate.

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42

Esteves, Sandra Raquel Ramires. "Monitoring and control of biological textile wastewater treatment using artificial neural networks." Thesis, Queen's University Belfast, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.395353.

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43

Bin-Fahad, Rashid Ahmed Mohammed. "Utilisation of anoxic/aerobic system for upgrading fixed-film biological wastewater treatment." Thesis, University of Strathclyde, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.248948.

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44

Morgan, Pamela B. "Study of population dynamics in a biological phosphorouos removal wastewater treatment system." Thesis, This resource online, 1993. http://scholar.lib.vt.edu/theses/available/etd-08182009-040452/.

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45

Essig, Erica Carla. "Long-term population trends and habitat preferences of waders at Strandfontein wastewater treatment works." Master's thesis, University of Cape Town, 2016. http://hdl.handle.net/11427/23782.

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The aims of the dissertation are to describe long term migrant and residential wader population trends at Strandfontein, and to identify the potential factors which influence local wader abundance. Once identified, these factors are integrated into a management plan that would create ideal wader habitat, and attract larger numbers of waders to Strandfontein.

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46

Xavier, Ana Elisa. "Thiocyanate degradation by a novel isolate." Thesis, University of Kent, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.332604.

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47

Yang, Ying, and 楊穎. "Characterization of broad-spectrum antibiotic resistance genes in wastewater treatment reactors through metagenomic approaches." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206338.

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48

Kunjikutty, Sobhalatha Panangattu. "Floodplain filtration for treating municipal wastewaters." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100641.

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The effectiveness of a cheap, low-tech, environmentally and technically favorable treatment of secondary treated municipal wastewater by contaminant removal through a floodplain-soil filter was evaluated using floodplain-simulating field lysimeters, packed with a sandy soil in 2002 and sand in 2003 and 2004. Secondary treated wastewaters from Vaudreuil (2002 and 2003) and Pincourt (2004) Wastewater Treatment Plants were used as influent. This was applied at rates of 0.06, 0.19, and 0.31 m3 m-2 d -1 to vegetated lysimeters, and at a rate of 0.19 m3 m-2 d-1 to bare-soil lysimeters.
Removal of NH4+-N, NO3--N, and COD from the influent was studied in all three years. Irrespective of flow rate or year, the system removed 62~84%, 96~99%, and 6~67% of TKN, NH4+-N, and COD, respectively, from the influent. Under 0.19 m3 m-2 d-1 flow rate, vegetated systems removed slightly more of these constituents from the influent, than did bare-soil lysimeters. Organic degradation mainly occurred in the top 0.1 m soil depth. Degradation of organic and inorganic influent nitrogen increased NO3--N levels in the effluent. Only minimal increases in soil-N levels and N2O emissions occurred with increasing application rates. The nitrogen mass balance accounted for 85∼98% (2003) and 67∼96% (2004) of input nitrogen (through leaching, soil retention, and N2O emissions), the remaining portion being attributable to vegetative effects and volatilization of non-N2O nitrogenous gases. The under established vegetation on the lysimeters reduced nitrogen leaching through soil, being 6% (2003) and 60% (2004) more effective than bare soil.
Effluent water quality improved with decreasing levels of heavy metals. Compared to influent levels, in vegetated lysimeters, under all flow rates, mean effluent As, Cd, Cu, Ni, Pb, and Zn levels had dropped by 58%, 9%, 3%, 37%, 63%, and 52% in 2003, and by 20%, 63%, 5%, 23%, 18%, 57%, and 79% for As, Cd, Cr, Cu, Ni, Pb, and Zn, in 2004. In both years, similar decreases in heavy metal levels occurred in the bare soil lysimeters. Across all flow rates and influent concentrations, soil heavy metal levels increased. In 2004, even low heavy metal content influent further increased (6∼179%) their accumulation in soil. As inputs of heavy metals to the soil increased with the increase in application rates, their associated times to reach maximum permissible limits also decreased.
LEACHN simulation of NO3--N in leachate arising from wastewater application, showed lowered levels with increasing flow rates, due to enhanced denitrification in the resulting anoxic upper soil zones. The simulation under continuous wastewater application at different range of nitrogen concentrations (low, medium, high) showed an increase of NO 3--N levels in the leachate with increasing N-levels. For all flow rates, and under tropical or humid conditions, the effluent NO 3--N levels remained below permissible limits for the low-N content wastewater applications. Intermittent applications, under all wastewater N-contents and flow rates, reduced NO3--N levels in the leachate by 51∼89% compared to continuous wastewater application, and permissible limits were not exceeded. Hence, wastewater with high levels of nitrogenous compounds, as occurs in most developing countries, could be treated by land under an intermittent application pattern, allowing a considerable reduction in nitrate pollution.

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Md, Som Ayub. "Development of a process selection model for industrial wastewater treatment using an expert system." Thesis, University of Southampton, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244969.

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Moore, Rebecca Ellen. "Development of a novel medium to improve the performance of Biological Aerated Filters (BAFs)." Thesis, Cranfield University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.340873.

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Dissertations / Theses on the topic 'Biological wastewater treatment'

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