Rozprawy doktorskie na temat „Sewage – Purification – Nutrient removal”
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1
Wong, Chiew Hiet. "Intergrated design of biological nutrient removal systems / by Chiew Hiet Wong". Thesis, The University of Sydney, 2001. https://hdl.handle.net/2123/27929.
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凌偉忠 i Wai-chung Jackson Ling. "Biological nutrient removal in sequencing batch reactors using fibrouspacking medium". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1996. http://hub.hku.hk/bib/B31213388.
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3
Sun, Feiyun, i 孙飞云. "A membrane bioreactor (MBR) for a biological nutrient removal system: treatment performance, membrane foulingmechanism and its mitigation strategy". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B44903856.
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Zeng, Raymond Jianxiong. "The role of intracellular storage products in biological nutrient removal /". St. Lucia, Qld, 2002. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe16445.pdf.
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5
Abu-Ghararah, Ziad. "The effect of influent organic compounds on the performance of biological nutrient removal systems". Diss., Virginia Polytechnic Institute and State University, 1988. http://hdl.handle.net/10919/77907.
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The main objective of the research was to investigate the effect of influent organic compounds on the performance of biological nutrient removal system. To carry out the investigation, a pilot plant system was designed and constructed. The system was operated as a UCT process at an influent flow rate of 0.15 liters/minute and a sludge age of 13 days. The influent wastewater was domestic sewage. Excess biological phosphorus removal and steady-state conditions were established before making experimental measurements, or adding supplemental substrate. The effects of separate addition of formic, acetic, propionic, butyric, isobutyric, valeric, and isovaleric acid, plus glucose, addition on phosphorus release under anaerobic conditions, and phosphorus uptake under aerobic conditions, were studied. The effects of the organic acid additions on the removal of nitrogen and COD, and changes in SOUR, MLVSS, and metals such as iron, magnesium, calcium and potassium, were also studied. In all experiments, the specific substrate was added continuously to the first anaerobic reactor for three days at an influent concentration of 100 mg COD/liter. Samples were collected from each reactor at the end of the addition period and analyzed for orthophosphate, nitrate, nitrite, sulfate, volatile fatty acids, COD, MLVSS, pH and metals. All added substrates, except formic acid and dextrose, caused significant increases in phosphorus release in the anaerobic stage, and phosphorus uptake, in the aerobic stage, and consequently, an increase in phosphorus removal efficiency. The molar ratios of phosphorus release to volatile fatty acid added obtained for propionic acid, acetic acid, butyric acid, and valeric acid were 0.44, 0.77, 0.78, and 1.72 respectively. However, on a COD basis, the greatest ratios of mg phosphorus released to mg COD utilized was produced by the addition of acetic acid (0.37) and valeric acid (0.19). It was also found that the branched organic acids, isobutyric and isovaleric, caused more phosphorus release in the anaerobic stage and better phosphorus removal efficiencies as compared with the nonbranching forms of the same organic acids. The molar ratios of phosphorus release for these two acids were 0.8 and 2.3, respectively, and on a COD basis were 0.16 and 0.25. For engineering applications, it is suggested by this research that at least 20 mg COD equivalent of acetic acid is needed for the removal of I mg phosphorus. The results obtained by this investigation were consistent with the hypothesis proposed by Marais et al., 1983. The most recent biochemical models, proposed by Comeau et al., 1986 and Wentzel et al., 1986, were also tested using the data collected in the present investigation. Both models, in most cases, overestimated the ratios of phosphorus release to volatile fatty acid utilized. A speculative model for anaerobic metabolism by poly-p bacteria of volatile fatty acids which contain both odd and even numbers of carbon atoms was proposed.
All added substrates produced no effect on both COD and TKN removals. Metal releases were found to correlate with the amount of phosphorus release.Ph. D.
6
Guo, Lei. "Optimization of BNR from wastewater using SBR and A²O processes". Thesis, University of Macau, 2011. http://umaclib3.umac.mo/record=b2493027.
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7
Zhang, Zhenhua. "Plant growth and nutrient removal in simulated secondary-treated municipal wastewater in wetland microcosmos". University of Western Australia. School of Earth and Geographical Sciences, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0141.
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[Truncated abstract] The use of constructed wetlands for tertiary purification of municipal wastewater has received increasing attention around the world because direct discharge of secondary-treated municipal wastewater to water bodies has caused eutrophication. Plant species selection and vegetation management may enhance nutrient removal efficiency in constructed wetlands. However, there is a lack of knowledge on the relations between plant growth and nutrient removal efficiency in constructed wetlands. The objective of this study is to better understand how plant growth and resource allocation are influenced by nutrients in wastewater and how nutrient removal efficiencies are affected by plant species and vegetation management. The preliminary experiment was conducted to select macrophytes, especially ornamental species, to grow in the wastewater in the wetland microcosms. Ten plant species, comprising six ornamental species: Alocasia macrorrhiza, Canna indica, Iris louisiana, Lythrum sp., Zantedeschia aethiopica, Zantedeschia sp., and four sedge species: Baumea articulate, Baumea juncea, Carex tereticaulis and Schoenoplectus validus, were planted in the wetland microcosms and fed a simulated wastewater solution in the concentrations similar to the secondary-treated municipal wastewater. C. indica has shown vigorous and healthy growth, and a relatively high potential of rooting-zone aeration and nutrient removal efficiency. B. articulata and S. validus also showed relatively high nutrient removal efficiency. ... The high nutrient availability and optimum N/P ratio were required for stimulating plant growth, resulting in allocation of more resources to above-ground tissues compared to below-ground parts, and enhancing nutrient removal efficiency. Nutrient removal efficiencies were significantly influenced by growth of C. indica and S. validus, nutrient loading rates and N/P ratios in the wastewater. The nutrient uptake kinetics of C. indica and S. validus were investigated to elucidate the differences in nutrient uptake between species. Wetland plant species have shown differential nutrient uptake efficiency and different preferences for inorganic N source, with C. indica preferring NO3-N and S. validus preferring NH4-N. C. indica had greater capacity than S. validus to take up PO4-P when the concentration of PO4-P in the solution was relatively low, whereas S. validus was more capable than C. indica to take up NO3-N when the concentration of NO3-N in the solution was relatively low. The PO4-P uptake capacity was higher in younger than older plants. Overall, the study has suggested that different plant species have differential capacity to take up nutrients. In addition to nutrient uptake, plants have significant other roles in terms of nutrient removal from the wastewater (such as leaking oxygen into the rhizosphere in which oxidation of substances like ammonia can occur). The properly high nutrient availability and optimum N/P ratio are required to stimulate the plant growth, resulting in enhancing the treatment performance in the wetlands. These findings have important implications for improving our ability to engineer ecological solutions to the problems associated with nutrient-rich wastewater.
8
Ginige, Pushpa. "Decontamination of biosolids for land application : metals bioleaching and process impacts on the nutrient value of biosolids". Thesis, Queensland University of Technology, 1998.
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au, rkurup@murdoch edu, i Rajendra Kurup. "An experimental research on application of sub-surface flow constructed wetlands for meat processing industry effluent treatment and nutrient removal". Murdoch University, 2007. http://wwwlib.murdoch.edu.au/adt/browse/view/adt-MU20070717.142408.
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Meat processing industries produce large volumes of high strength wastewater.
Conventional technologies used in Australia and similar countries for treatment of
effluent from meat processing and similar industries, such as wineries and processed
food industry, are treatment ponds with or without a mechanical treatment system.
A properly designed activated sludge treatment system would be capable of biological
removal of phosphorus and nitrogen in addition to BOD5. These systems, however,
require substantial electrical power, skilled operational support and produce large
quantities of biosolids or sludge which require further on-site treatment or off site
disposal. Application of sub-surface flow constructed wetland (SSF-CW) systems could
provide a sustainable solution for treatment of meat processing industry effluent and
other similar high strength wastewaters. There are, however, only very limited studies
on application of SSF-CW for secondary treatment of high strength wastewaters.
Although there have been a number of cases where SSF-CW have been used as the
secondary treatment unit for municipal wastewater, this technology has not still become
a common practice for the same purpose in Australia. Most of the applications are for
either polishing of secondary or tertiary treated municipal wastewater or for greywater
treatment.
This research was funded by National Meat Industry Advisory Council (MINTRAC).
Sustainable wastewater treatment has been taken up as a very important issue by meat
industry. The industry provides Ph.D research scholarships through MINTRAC to
develop new technologies for wastewater treatment and nutrient removal from meat
processing effluent.
The main objective of the research was to develop process engineering design
parameters for sub-surface flow constructed wetland (SSF-CW) with Monto vetiver
(Vetiveria zizanioides recently reclassified as Chrysopogon zizanioides) as the emergent
vegetation for treatment of high strength, nutrient rich wastewater. The study also
investigated the phosphorus retention properties of pea gravel for use in SSF-CW
system as bed media or as an external phosphorus removal system for meat processing
industry effluent. In addition, chemical methods for phosphorus removal from meat
processing industry effluent were also investigated.
The thesis is based on experimental research. The research consisted of three types of
experimental set up; a) using two laboratory experimental SSF-CW reactors (one with
vetiver grass and the other reactor with no vegetation) in a greenhouse with batch
feeding of artificial wastewater that simulates meat industry effluent, b) experiment with
pea gravel of different particle sizes and solutions of different phosphorus (P)
concentrations in a constant temperature room, c) laboratory experiment using actual
meat processing industry effluent with alum and sodium aluminate for P removal.
The structure of the thesis is as follows. Following the Introduction is the section of
Literature Review, then sections on the experiments that follow a journal paper format,
followed by a General Discussion, Conclusions and Recommendations. A list of
references is provided at the end of the thesis.
The literature review section has four chapters (Chapter 2 to Chapter 5). Chapter 2
describes a review of meat processing industry effluent characteristics and current
treatment technologies. Chapter 3 is a critical review of current literature on COD
removal using sub-surface flow constructed wetlands (SSF-CW). Chapter 4 and 5
describe a review of various processes and models on the fate of nitrogen and
phosphorus in SSF-CW system respectively.
Chapters 6 to 10 deal with experimental research part of the thesis. Chapters, 6, 7 and 8
share a common methodology section which is described in Chapter 6. Results of the
batch experiments with the laboratory SSF-CW systems on COD removal, nitrogen
removal and phosphorus retention are discussed in Chapters 6, 7 and 8 respectively.
Chapter 9 explains a detailed experimental study on phosphorus adsorption dynamics of
pea gravel. Chapter 10 discusses the results on experiments using sodium aluminate and
aluminium sulphate for P removal from meat processing industry effluent as an alternate
P removal method for such effluent.
An overview of the major results of the experimental section is discussed in chapter 11,
in the General Discussion section. Conclusions and Recommendations of the research
are provided in Chapter 12.
In this study, it was observed that Monto vetiver grass performed better during
nitrification than in denitrification, where the plant did not survive. Ammonium N
removal followed a first order decay in both vegetated and un-vegetated experimental
SSF-CW system with average removal ranging from 40 to 60 % of the influent.
Denitrification was found to be the pathway for nitrate removal. As long as the carbon
source was available, the denitrification followed a first order exponential decay, with
over 80% of nitrate was removed in 48 hours. Vetiver grass sustained elevated
ammonium levels of approximately 200 mg/L or more, however it was under stress
during denitrification and it eventually died.
The experimental SSF-CW systems with pea gravel as bed media could effectively
retain soluble reactive phosphorus (SRP) in the wetland cells during experiments of
COD reduction and nitrification (with ammonia and high COD input). However, during
denitrification study, both experimental SSF-CW cells did not show significant removal
of SRP from wastewater. The vegetated cell removed nearly 50% of the input SRP,
however, the un-vegetated cell did not show any trend for SRP removal, and in some
cases the effluent SRP was nearly 90% of the input value.
The role of Monto vetiver grass for N and P removal was found to be very minor and
this study concluded that nutrient removal (N & P) by plant uptake could be neglected
in the design of SSF-CW system with Monto vetiver grass.
Adsorption is the major mechanism for P removal from the experimental SSF-CW
systems, where pea gravel was used as bed media. The P adsorption capacity of pea
gravel increased with decrease in particle size. For 16 to 18 mm, the Langmuir
adsorption maximum was 99 mg/kg, whereas for very fine pea gravel powder (<150
ìm) the maximum adsorption observed experimentally was 3950 mg/kg. In a typical
wetland with pea gravel as bed media for meat processing industry, the media would be
capable of P retention for about 2 to 3 years of operation. Supplementary chemical
removal method is needed for sustainable P removal once the adsorption maximum of
wetland cell is reached.
A chemical P removal system using liquid alum and NaOH for pH stabilisation is more
appropriate than sodium aluminate. Application of sodium aluminate for P removal for
meat processing industry effluent is found to be less effective as it would need higher
dosage, longer settling period, coloured supernatant, acid addition for pH adjustment.
Liquid alum application rate is recommended to be between a molar ratio of Al: P of 3
for TP value of <1 mg/L in the treated effluent.
This research study concludes that horizontal flow SSF-CW system with Monto vetiver
grass is suitable for COD removal and nitrification from high strength wastewater.
Current design equation of horizontal flow SSF-CW system is mostly plug flow
exponential decay method, but in this study, it has been concluded that retarded first
order rate constant is the most appropriate design method for horizontal flow SSF-CW
system for COD removal.
10
Randall, William O. "The Effects of a phosphate detergent ban on a biological nutrient removal plant and anaerobic digester /". Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03122009-040637/.
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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.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).
M.S.
Masters
Civil, Environmental and Construction Engineering
Engineering and Computer Science
12
Abzazou, Souisa Tarik. "Técnicas moleculares para la caracterización microbiológica de los procesos de eliminación de nutrientes en las EDARs = Molecular techniques for microbiological characterization of nutrient removal processes at WWTPs". Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/402738.
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La presente tesis titulada Técnicas moleculares para la caracterización microbiológica de los procesos de eliminación de nutrientes en las EDARs, se ha desarrollado desde dos puntos de vista, el primero fue la puesta a punto de diferentes técnicas moleculares para la caracterización de las comunidades microbianas, especialmente las comunidades responsables de eliminación de nutrientes, presentes en las EDARs. El segundo fue la aplicación de las técnicas, desarrolladas en el primer punto, para cuantificar y caracterizar las distintas comunidades microbianas y su relación con el funcionamiento de los procesos de depuración de las aguas residuales.
Los dos bloques mencionados arriba se llevaron a cabo en tres capítulos que forman la columna vertebral de la tesis. En el primer capítulo de la tesis se desarrollaron y aplicaron las técnicas de citometría de flujo y microscopía de epifluorescencia para la cuantificación numérica y de viabilidad de las células procariotas presentes en los reactores biológicos de dos EDARs que funcionan con proceso de fangos activos con aireación prolongada. Durante varios meses muestras de fangos activos han sido analizadas a escala de laboratorio aplicando las técnicas de citometría y microscopía de epifluorescencia combinadas con fluorocromos de marcaje molecular de los ácidos nucleicos. La realización fiable de los análisis con ambas técnicas solo ha sido posible tras un tratamiento previo de las muestras mediante un protocolo de desagregación de los flóculos de fangos presentes en las muestras. Los resultados se compararon entre ambas técnicas, los resultados no revelaron diferencias significativas entre sí. Sin embargo la técnica de citometría mostró ser la mejor opción debido a la sencillez y rapidez de los análisis. Por otra parte la caracterización de las EDARs estudiadas mostró una gran estabilidad del proceso de fangos activos con aireación prolongada, una de las características más destacadas del sistema que le otorga la gran aplicabilidad que tiene dentro de los procesos de fangos activos y sus variantes. En el segundo capítulo se aplicó la técnica de hibridación In situ fluorescente junto con la técnica de DAPI para cuantificar y caracterizar las comunidades nitrificantes y bacterias totales, respectivamente, en una planta piloto de nitrificación parcial con sistema de lechos móviles (carriers). Ambas técnicas mostraron su gran utilidad en base a los resultados obtenidos que fueron en acuerdo con el funcionamiento observado en la planta piloto. En este capítulo se logró obtener un sistema de nitrificación parcial en base a los parámetros operacionales sobre todo mediante el control de la temperatura del sistema y el tiempo de retención hidráulico. Por último, en el capítulo tres, se ha investigado un nuevo enfoque de diseño de estándares para la técnica de qPCR para la cuantificación y caracterización de las comunidades microbianas presentes en tres EDARs con procesos operacionales biológicos distintos. La técnica de diseño de estándares aplicada fue la técnica de Double-stranded gBlocks Gene Fragments. Los microorganismos estudiados fueron las bacterias totales, bacterias nitrificantes, arqueas, microorganismos acumuladores de polifosfato. Estos últimos fueron estudiados mediante la técnica de FISH por falta de sondas fluorogénicas específicas para su cuantificación mediante qPCR. Los resultados obtenidos mostraron la gran utilidad de la técnica de gBlocks como método fácil, rápido y asequible para el diseño de estándares. Todos los estándares estudiados fueron mejorados. El estudio de las EDARs tanto a nivel microbiológico como operacional reveló ciertas correlaciones significativas entre ambas partes, mientras otras no fueron muy concluyentes debido a varios factores como pueden ser limitaciones del método de extracción de ADN, el nivel especificad de algunas sondas de ADN. Todas estas hipótesis se han de estudiar más adelante con el objetivo de entender mejorar algunas estas correlaciones.
13
Goolsby, Matthew Allen. "Viability study of a residential integrated stormwater, graywater, and wastewater treatment system at Florida's Showcase Green Envirohome". Master's thesis, University of Central Florida, 2011. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4767.
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The subject of water scarcity and the rate of water consumption have become popular over the last few decades. Within the topic of water consumption, there are two separate issues from a residential standpoint. The first concern is the steadily increasing need for viable alternative water sources to be utilized for non-potable applications in an effort to reduce potable water demands. The second concern is the need to significantly reduce of nutrient-laden wastewater effluent discharge from septic systems in order to sustain groundwater quality and prevent adverse ecological impacts. This study addresses both issues with two separate systems integrated into one environmentally functional home that emphasizes low impact development (LID) practices. The first objective of the study is to quantify the performance of the passive treatment Bold & GoldTM reactive filter bed (FDOH classified “innovative system”) for nutrient removal. The second objective is to monitor the water quality of the combined graywater/stormwater cistern for non-potable use and asses all components (green roof, gutters, graywater treatment, AC condensate, well water, stormwater contribution). The performance of the passive innovative system is compared to past studies and regulatory standards. Also, a bench scale model of the OSTDS is constructed at the University of Central Florida (UCF) Stormwater Management Academy Research and Testing Lab (SMART Lab) and tested to provide effluent data at two different residence times. Complex physical, biological, and chemical theories are applied to the analysis of wastewater treatment performance. The data from the OSTDS and stormwater/graywater cistern both systems are also assessed using statistical analysis. The results of the OSTDS are compared to FDOH regulatory requirements for “Secondary Treatment Standards”, and “Advanced Secondary Treatment Standards” with positive results. The bench scale results verify that both biological nutrient removal and physiochemical sorption are occurring within the filter media and quantified the relationship between removal rates and hydraulic residence time (HRT). The combined graywater/stormwater cistern contains acceptable water quality and operates efficiently. The demand on the cistern results in about 50% capacity utilization of the cistern and there is a consistent dependency on the artesian well. The salinity content and high sodium adsorption ratio (SAR) of the cistern water did not produce any noticeable adverse impacts on the home other than scale formation in the toilet. The results of the research determined that the implementation of the integrated system is a viable option at the residential level.ID: 030646271; 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. 124-129).
M.S.Env.E.
Masters
Civil, Environmental and Construction Engineering
Engineering and Computer Science
Environmental Engineering
14
Jomaa, Samir. "Combined sludge treatment and production of useful by-products using hydrothermal oxidation". Thesis, Queensland University of Technology, 2001.
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Steffens, Marc Alexander. "Advanced process control for nutrient removal activated sludge processes /". [St. Lucia, Qld.], 1997. http://library.uq.edu.au/screens/steffens.html.
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Ling, Wai-chung Jackson. "Biological nutrient removal in sequencing batch reactors using fibrous packing medium /". Hong Kong : University of Hong Kong, 1996. http://sunzi.lib.hku.hk/hkuto/record.jsp?B17489477.
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Copp, John B. "COD balances in biological nutrient (nitrogen and phosphorus) removal activated sludge systems /". *McMaster only, 1998.
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Mao, Yanping, i 毛艷萍. "Biological removal of phosphorus and nitrogen from wastewater : new insights from metagenomic and metatranscriptomic approaches". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2014. http://hdl.handle.net/10722/206323.
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Popple, Tina. "The behaviour, fate and removal of pharmaceuticals in biological nutrient removal sewage treatment". Thesis, University of Portsmouth, 2013. https://researchportal.port.ac.uk/portal/en/theses/the-behaviour-fate-and-removal-of-pharmaceuticals-in-biological-nutrient-removal-sewage-treatment(7b67f73d-d777-4a25-9b7b-0ae3edcc58dc).html.
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Pharmaceuticals that are intended for human use are frequently detected in the aquatic environment. This is predominantly from the excretion of pharmaceuticals by patients, in their urine and faeces, which subsequently enter sewage treatment plants. Sewage treatment provides a final opportunity for pharmaceutical removal, prior to discharge into the environment, however, removal is often incomplete. Once in the environment, pharmaceuticals have the potential to cause effects on aquatic organisms. Sewage treatment plants, that are designed to meet statutory discharge consents for nutrients, are increasing in number. These plants, capable of biological nutrient removal, are understudied for the removal efficiencies of pharmaceuticals. This thesis presents research findings on the behaviour, fate and removal of selected pharmaceuticals in a bespoke laboratory rig, and in operational biological nutrient removal sewage treatment plants. Pharmaceuticals possessing a broad range of physical and chemical properties were selected for this research, they included: salicylic acid, caffeine, propranolol, diclofenac and carbamazepine. Sensitive chromatographic methods were developed to quantify the analytes in a laboratory sequencing batch reactor rig and in operational plants. Radiolabelled 14C isotopes of salicylic acid, caffeine, propranolol and diclofenac were dosed into the laboratory rig. The compounds exhibited different behaviours during a simulated sewage treatment process. Salicylic acid and caffeine produced the highest amount of biodegradation, with 25.2% and 14.5% of the radiolabel mineralised to 14CO2 in the rig. However, parent degradation is likely to have been higher, since neither compound could be detected in the effluent by specific chemical analysis. These findings were replicated in the operational sewage treatment plants, with > 97% removal of both pharmaceuticals, in all three plants investigated. Propranolol and diclofenac were less affected by biodegradation processes, and produced 3.7% and 0.2% mineralisation, respectively, in the laboratory rig. Furthermore, 33.8% of the radioactivity associated to 14C propranolol was detected in the rig solids. These compounds showed insignificant removal from two operational plants; 6.8% and 20.9% (propranolol) and -0.9% and -39.4% (diclofenac). Monitoring of operational plants showed that concentrations of propranolol were highest in the activated sludge tanks at all three sites. This supports the findings from the rig, that propranolol interacts with the sludge, which might be more significant in plants with lower sludge wastage rates, such as sequencing batch reactors. This could have implications for the terrestrial environment, and therefore, terrestrial risk assessments should be refined accordingly. Monitoring of the operational sewage treatment plants highlighted the widespread presence, and recalcitrant behaviour, of carbamazepine during biological sewage treatment. Future work should focus on investigating the mechanisms of removal, of this pharmaceutical in the laboratory sequencing batch reactor. This work highlighted the problems biological systems face in effectively removing recalcitrant pharmaceuticals. Advanced wastewater treatment should be considered, if complete removal is desired.
20
Cao, Keping. "Simultaneous Removal of Carbon and Nitrogen by Using a Single Bioreactor for Land Limited Application". Thesis, Water Resources Research Center, University of Hawaii at Manoa, 1998. http://hdl.handle.net/10125/22230.
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An Entrapped-Mixed-Microbial-Cell (EMMC) process was investigated for its simultaneous removal of carbon and nitrogen in a single bioreactor with the influent COD/N ratio varying from 4 to 15 and influent alkalinity of 140 mg CaCO3/L and 230 mg CaCO3/L. The reactor was operated with alternate schedules of intermittent aeration. Two different sizes of carriers (10 * 10 * 10 mm3 and 20 * 20 * 20 mm3) were studied.
The medium carrier (10 * 10 * 10 mm3) system presents higher nitrogen removal and COD removal compared to the large carrier system. The nitrogen removal efficiency is related to the ratio of COD/N in the influent. With the increase of the COD/N ration in the influent, the nitrogen removal efficiency is increased.
The average reductions of nitrogen were over 92% and the average reductions of SCOD and BOD5 are over 95% and 97%, respectively, in the medium carrier system. This is operated at the HRT of 12 hours and 0.5 hour aeration and 2 hours of non-aeration, and the COD/N ratio of 15 in the influent. Changing alkalinity from 140 to 230 mg CaCO3/L has no effect in both large and medium carriers for the nitrogen removal efficiency.
The pH, oxidation – reduction potential (ORP) and dissolved oxygen (DO) were used to monitor the biological nitrogen removal. It was found that the ORP (range from -100 to 300 mV) can be used to provide better effluent quality measured as total-nitrogen of less than 10 mg/L. Also, the impact of influent COD/N ratio on the effluent quality (measured as Inorg.-nitrogen) for the EMMC process is very important.
Compared to other two compact biological wastewater treatment processes, membrane bioreactor (MBR) and moving bed biofilm reactor (MBBR), the EMMC process with the intermittent aeration has higher removal efficiencies of carbon and nitrogen, easier operation, lower O&M cost, lower energy requirement, and more compact. The total cost requirement is less than $3.27 per 1000 gallons (3.785 m 3) of treated settled domestic sewage per day. It is apparent that the EMMC process is technically feasible for the simultaneous removal of carbon and nitrogen under the operation on a schedule of intermittent aeration and suitable to be used for replacement or upgrading of existing treatment plant at land limited area.
21
Chen, Wen, i 陳雯. "A membrane bioreactor(MBR) for an innovative biological nitrogen removal process". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2007. http://hub.hku.hk/bib/B39557959.
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Morrison, Kirk Murray. "An assessment of the potential for biological phosphorus removal in Canadian wastewater treatment plants". Thesis, University of British Columbia, 1988. http://hdl.handle.net/2429/28507.
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This thesis assesses the potential for enhanced biological phosphorus (Bio-P) removal in Canadian wastewater treatment plants. Retrofit designs incorporating Bio-P removal were prepared for nine wastewater treatment plants across Canada, and were compared against chemical phosphorus removal technologies. Incremental capital and operating costs were calculated and internal rates of return (IRR's) for the capital investment required to install the Bio-P removal facilities were calculated. Based on these results, an assessment of the potential use for the technology in Canada is made.
Of the nine plants studied, results indicate that Bio-P removal is economically superior to chemical phosphorus removal for the Calgary Bonnybrook, Edmonton Gold Bar, Saskatoon Mclvor Weir and Regina wastewater treatment plants. In general, Bio-P removal appears to offer significant economic advantages to
plants located in Alberta and Saskatchewan because of the high
cost of phosphorus removal chemicals in these provinces. The
present low cost of phosphorus removal chemicals in Ontario and
Quebec likely limits the viability of Bio-P removal to large (greater than 300,000 m³/d), suitably configured plants. In British Columbia, where Bio-P removal is presently used in the Okanagan Valley, the absence of widespread provincial phosphorus removal standards makes future Bio-P installations unlikely. The potential for Bio-P removal in Manitoba, the Maritimes and the Yukon and Northwest Territories is again limited by the absence of phosphorus removal standards in these parts of Canada.
Results also indicate that the use of an anoxic/anaerobic/ aerobic process in the bioreactor, in conjunction with primary sludge fermentation through gravity thickening, is very applicable to Canadian plants and offers potential capital and operating cost savings relative to other Bio-P processes. The common practice of anaerobic sludge digestion, combined with sludge dewatering and land application, was found to be unfavourable from a Bio-P perspective unless the resulting supernatant/filtrate streams can be re-used or disposed of outside of the mainstream treatment process.
Through the preparation of the retrofit designs, it was
determined that certain aspects of Bio-P technology require additional research in order to optimize treatment plant design.
These include kinetic modelling; short SRT Bio-P removal; the
anorexic/anaerobic/aerobic process; the use of gravity thickening
for primary sludge fermentation; and phosphorus release during anaerobic digestion.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
23
Yan, Qingmei, i 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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楊龍元 i Lung-yuen Christopher Yeong. "Removal of wastewater cod and nitrogen using fibrous packing media". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1991. http://hub.hku.hk/bib/B31210636.
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25
Zhao, Kang, i 趙鈧. "An iron-facilitated chemical and biological process for phosphorus removal and recovery during wastewater treatment". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2013. http://hdl.handle.net/10722/196027.
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Phosphorus (P) is an important pollutant of concern in wastewater that causes eutrophication and algal blooms in water body. On the other hand, P is a valuable natural resource for agricultural and industrial use. With the rapid depletion of mineral phosphorus on earth, there is a need to recover phosphorus from wastewater. In this study, a new chemical and biological process facilitated with iron dosing has been developed for P removal and recovery during wastewater treatment. The system consists of a main stream identical to the conventional activated sludge process in an aerobic sequencing batch reactor (SBR) for P removal and a side stream of sludge recirculation through an anaerobic SBR (AnSBR) for P release and recovery from the P-rich sludge.
In the aerobic SBR treating a synthetic domestic wastewater, Fe(III) (FeCl3) was dosed to remove P by precipitation and adsorption. Fe(III) dosing at a Fe/P molar ratio of 1.5:1 could reduce the P concentration from more than 10 mg/L to below 1 mg/L in the final effluent. Compared to other dosing periods, dosing Fe(III) right before the SBR settling could achieve the best result in sludge flocculation and P removal. Meanwhile, organic removal was well maintained as 90% of the chemical oxygen demand (COD) was degraded in the aerobic SBR. In the AnSBR, phosphate precipitated with ferric iron in the sludge was released owing to microbial Fe(III) reduction, and a positive correlation was found between the phosphate and ferrous iron concentrations in the sludge suspension. Chemical tests showed that significant P release from Fe(III)-P occurred only if the acidic condition and the reducing condition were combined. For the AnSBR sludge, a higher organic loading, lower pH and higher biomass concentration resulted in a higher level of Fe(III) reduction and P release. Organic acidogenesis prevailed in the reactor and lowered the pH to ~4.5, which facilitated the P release from the solid phase into the liquid phase. With a solids retention time (SRT) of 10 days, the anaerobic supernatant contained a phosphate concentration of up to 70 mg/L, while the settled sludge was returned to the aerobic SBR. The phosphate could be readily recovered from the supernatant with Fe-induced precipitation by aeration and pH adjustment, and the overall P recovery could be achieved at about 70%. In addition to the treatment performance, the speciation of P in the aerobic sludge and the anaerobic sludge also was investigated. A significant change in the immediately available P and the redox-sensitive P was found in the sludge through the aerobic-anaerobic cycle. Such chemical transformation is believed to be crucial to the P removal and recovery during the wastewater treatment process.published_or_final_version
Civil Engineering
Master
Master of Philosophy
26
Clayton, John Andrew. "Denitrification kinetics in biological nitrogen and phosphorus removal activated sludge systems". Master's thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/21139.
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In order to size the anoxic reactors in nutrient (N and P) removal activated sludge plants, it is essential to know the denitrification kinetics that are operative in such systems. To date, denitrification kinetics have been accurately defined only for systems that remove N alone; little research has been performed on denitrification in N and P removal plants.
27
Lee, N. P. (Nelson Paul). "The affect of anaerobic volume reduction on the University of Cape Town (UCT) biological phosphorus removal process". Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29631.
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The objective of this research was to optimize the bio-P process as applied to a weak sewage with respect to HRT in each of the process zones. This goal was to be achieved by changing the HRT of the various zones with all other operating characteristics being held constant.
The experimental work during this study involved two initially identical process trains operated in the University of Cape Town (UCT) mode. The aerobic zones of both trains were divided into four equal sized complete-mix cells to allow observations of phosphate uptake and poly-β-hydroxyalkanoate (PHA) consumption under aerobic conditions. After steady-state was established, the anaerobic HRT was reduced to 50% of the original value in the experimental module by reducing the anaerobic reactor volume. At the same time, the mixed liquor of both trains was drained, mixed and reapportioned to the two processes, thereby assuring equivalent starting conditions.
Results of this study showed that both processes performed identically prior to the anaerobic HRT change. After the anaerobic HRT change, there was a forty day period where P removal and effluent P were the same in both process trains. This was so, even though the anaerobic P release was considerably less in the experimental module. Subsequently, a change in influent sewage type corresponded to a change in P removal and effluent P in the two process trains. An examination of the process parameters showed that the anoxic zone of the experimental module, after the anaerobic HRT change and the sewage change, consistently removed less P or released more P than
in the control module. As a result, the control module out-performed the experimental module. Batch tests and tests to better characterize the influent sewage were then conducted in an attempt to determine the reasons for the different P removal characteristics.
Under the test conditions, it appeared that the original anaerobic HRT was excessive. This was preferable to an insufficient anaerobic HRT, such as in the experimental module, however. The anoxic zone may have been too large, too small or just right for optimum P removal depending on the influent sewage characteristics. Optimizing the bio-P process by reducing the aerobic zone HRT appeared to have the greatest potential.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
28
Casher, Thomas Christopher. "Biological excess phosphorus removal under high rate operating conditions in a suspended growth treatment process". Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29464.
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The primary objective of this research was to determine if efficient biological phosphorus removal could be established under low sludge retention time of 2 days and a nominal hydraulic retention time of 4 to 6 hours. The two-stage Phoredox process was selected because of the practical application of retrofitting high rate treatment plants to achieve bio-P removal without the additional tankage required for an anoxic section and the additional expense of a recycle system.
It has been shown that nitrate recycled into the anaerobic reactor impacts on bio-P removal and the two-stage Phoredox process provides no control over nitrates entering the anaerobic reactor. Therefore a secondary objective of this research was to determine if a low sludge retention time mode of operation could be used as an effective way to prevent nitrification in the activated sludge treatment process.
Another objective was to observe mixed liquor settling characteristics of the two-stage Phoredox process operated under high rate conditions.
A pilot scale two-stage Phoredox activated sludge treatment process operating under high rate conditions was used to meet these objectives. The desired bio-P removal biomass was not observed under SRT operating conditions of 2, 3 and 5 days. Partway into the research a sludge bulking condition developed which was identified as filamentous
growth. On two occasions this severe filamentous growth resulted in the process failing and the system being restarted.
On one occasion after the system was restarted using a seed sludge from a three-stage Phoredox pilot plant, a bio-P removal biomass was present. This condition only lasted for a short period and ended as filamentous growth began to become dominant. The process failed because of this phenomenon.
The system was restarted using a seed sludge and again filamentous growth dominated. Chlorine addition was found to be the only method to control this phenomenon and was continued to the end of the research. The desired bio-P removal biomass was not observed even during the last period of the research when the SRT was increased to 8 days.
During this research a stable bio-P removal biomass was not established. For a short period a bio-P removal biomass was present but failed to persist. Nitrification never became established at any time. Sludge settleability was poor due to filamentous growth which developed partway into the research and was present throughout the remainder of the study. Chlorine addition was the only method found that remedied this settling problem.Applied Science, Faculty of
Civil Engineering, Department of
Graduate
29
Brannan, Kenneth P. "Substrate stabilization in the anaerobic stage of a biological phosphorus removal system". Diss., Virginia Polytechnic Institute and State University, 1986. http://hdl.handle.net/10919/49992.
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30
Banihani, Qais Hisham. "ANAEROBIC - AEROBIC TREATMENT OF DOMESTIC SEWAGE". Diss., The University of Arizona, 2009. http://hdl.handle.net/10150/193820.
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Domestic wastewater is the most abundant type of wastewater. Direct discharge of untreated domestic wastewater has environmental and public health risks due to the presence of organics, nutrients and pathogens. Application of anaerobic processes for the treatment of domestic sewage, which at present is largely treated by aerobic processes, has drawn considerable attention recently. Anaerobic processes can be applied for the removal of organic matter (methanogenesis) and nitrogen (anaerobic ammonium oxidation (Anammox)).The toxicity of fluoride to methanogenesis was investigated. The results indicate that acetoclastic were more susceptible to fluoride than hydrogenotrophic methanogens. The concentration of fluoride causing 50% inhibition (IC50) to acetoclastic ranged from 18.1 to 155.7 mg L-1 while for hydrogenotrophic methanogens was > 400.0 mg L-1.The feasibility of a combined system consisting of anaerobic up-flow anaerobic sludge blanket (UASB) followed by aerobic activated sludge (AS) reactor for removal of carbonaceous and nitrogenous contaminants from strong synthetic sewage (2.5 g chemical oxygen demand (COD) L-1) was also studied. The average combined removal of total COD, volatile fatty acids (VFA) and protein was higher than 89.0%, 99.0% and 97.0%; respectively. Extensive nitrification (96.0%) was observed when dissolved oxygen (DO) concentration was > 2.0 mg L-1. In contrast, only partial nitrification occurred when the AS received high organic loads and/or the DO level was below 2.0 mg L-1.The inhibitory effect of nitrite and nitrate on methanogenesis was evaluated. Methanogenic activity was inhibited by the presence of NOx- compounds (i.e., nitrite and nitrate). The inhibition imparted by nitrate was not due to the nitrate itself, but rather to its reduced intermediate, nitrite. The toxicity of NOx- to methanogens was found to be reversible after all the NOx- were reduced during denitrification.Moreover, the development of Anammox enrichment cultures was evaluated. Anammox cultures were successfully developed using sludge samples collected from municipal wastewater treatment plants (WWTPs) as inocula but not from methanogenic granular sludges. Return activated sludge (RAS) collected from WWTP operating for biological nitrogen removal had the highest intrinsic level of Anammox activity. RAS Anammox culture was developed rapidly within 40 days with a doubling time of 6.8 days.
31
黃金華 i Kam-wah Wong. "Deritrification in the activated sludge process with controlled anoxicconditions in the aeration tank". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1987. http://hub.hku.hk/bib/B31208423.
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McClintock, Samuel Alan. "Effects of temperature and mean cell residence time on the performance of high-rate biological nutrient removal processes". Diss., This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-08252008-162825/.
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Shetty, Ameesha R. "Metal anion removal from wastewater using chitosan in a polymer enhanced diafiltration system". Link to electronic thesis, 2006. http://www.wpi.edu/Pubs/ETD/Available/etd-050406-115241/.
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34
Mann, Robert A., of Western Sydney Hawkesbury University i Faculty of Science and Technology. "Phosphorus removal by constructed wetlands : substratum adsorption". THESIS_FST_XXX_Mann_R.xml, 1996. http://handle.uws.edu.au:8081/1959.7/333.
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The phosphorus removal characteristics of several gravel-based constructed wetland systems (CWSs) in the treatment of secondary sewage effluent was studied.Investigations were conducted on water quality parameters (redox potential, pH, dissolved oxygen and temperature) which affect phosphorus adsorption to substrata.Laboratory phosphorus adsorption experiments on Richmond CWS gravel substrata, a gravel used in Griffith CWS trials and a locally available soil, Hawkesbury sandstone, involved ion-exchange experiments and calculation of Langmuir and Freundlich adsorption isotherms and column adsorption/desorption trials.Six steelworks by-products were investigated in laboratory studies, to determine their potential for use as phosphorus adsorbers in a CWS: granulated blast furnace slag(GBF), blast furnace slag(BF), steel slag(SS), fly ash(FA), bottom ash(BA) and coal wash(CW).The ability to adsorb phosphorus was then correlated to the chemical attributes of each substratum.Of the six steelworks by-products screened in laboratory-based studies as substrata for P removal in a CWS, BF and SS slags showed the most potential due to their high phosphorus adsorption capacity and useable matrix size.Further research is recommended to evaluate the sustainability of using slags for P removal (as well as other contaminants present in wastewater), using full scale CWSs, which should include an evaluation of any likely environmental impacts using leachability and toxicity studies.Doctor of Philosophy (PhD)(Environmental Science)
35
Rubidge, Gletwyn Robert. "Evaluation and optimization of selected methods of arsenic removal from industrial effluent". Thesis, Port Elizabeth Technikon, 2004. http://hdl.handle.net/10948/230.
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This research was directed at reducing arsenic levels in the effluents generated at the Canelands facility that manufactures monosodium methyl arsenate. Two effluent streams containing arsenic have to be considered, a raw water stream that is treated on site and a brine stream that is disposed of by sea outfall. Removal of arsenate from aqueous media by coagulation was investigated and models were developed describing selected variables that influence the removal of the arsenate. Three coagulant systems were investigated, namely aluminium(III) coagulation, iron(III) coagulation and binary mixtures of aluminium(III) and iron(III). Researchers have studied individual aluminium (III) sulphate and iron(III) chloride coagulation. No detailed research and modelling had, however, been carried out on the use of binary mixtures of aluminium (III) sulphate and iron (III) chloride coagulation of aqueous arsenate, nor had individual aluminium(III) sulphate and iron(III) chloride coagulation of arsenate been modelled at relatively high arsenate concentrations. The models that were generated were validated statistically and experimentally. The variables investigated in the aluminium(III) model included initial arsenate concentration, pH, polymeric flocculent concentration, aluminium(III) concentration and settling time. The variables modelled in the iron(III) coagulation were initial arsenate concentration, pH, polymeric flocculent concentration, and iron(III) to arsenic mole ratio. The modelling of the binary coagulant system included initial arsenate concentration, pH, iron (III) concentration, aluminium(III) concentration, and flocculent concentration as variables. The most efficient arsenic removal by coagulation was iron(III), followed by the binary mixture of aluminium(III) and iron(III) and the weakest coagulant was aluminium(III) sulphate. Scale-up coagulations performed on real raw water samples at a 50 litre volume showed that iron(III) was the most efficient coagulant (on a molar basis) followed closely by the binary mixture, while aluminium(III) coagulation was considerably weaker. The residual arsenic levels of the iron(III) and the binary coagulation systems met the effluent discharge criteria, but the aluminium coagulation system did not. Leaching tests showed that the iron(III) sludge was the most stable followed by the sludge of the binary mixture and the aluminium(III)-based sludge leached arsenic most readily. Settling rate studies showed that the flocs of the iron(III) coagulations settled the fastest, followed by binary mixture flocs and the aluminium flocs settled the slowest. The flocs of the binary mixture had the lowest volume, followed by the iron(III) flocs, while the aluminium(III) flocs were the most voluminous. Based on current operations of the raw water treatment plant the aluminium(III)-based coagulation is the most cost efficient. Given a relative costing of 1.00 for the aluminium(III) coagulation, the iron(III) chloride-based coagulation would be 2.67 times more expensive and the equimolar binary mixed aluminium(III)/iron(III) system would be 1.84 times the cost of aluminium(III) coagulation.
36
Cronje, Martin. "Investigation of electrochemical combustion plant for rural water disinfection and industrial organic effluent removal". Thesis, Stellenbosch : University of Stellenbosch, 2004. http://hdl.handle.net/10019.1/16292.
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Thesis (MScIng)--University of Stellenbosch, 2004.ENGLISH ABSTRACT: Recent years have seen the development of various treatment methods for the purification of industrial waste waters due to the increased demand for reduced pollutant effluents. Aqueous waste streams containing toxic organic compounds are of special interest, since conventional treatment methods such as biological waste treatment can not always be used. Other popular treatment methods are often ineffective. Catalytic oxidation of organic wastes has been investigated since the 1960s with varying degrees of success. A major problem associated with this method is the high temperatures and pressures required to improve the activation energies involved. Electrochemical oxidation has become a popular method in the literature of treating these wastes, since the applied voltage determines the activation energy, and therefore the process can often be performed at ambient conditions. This thesis investigates the capability of a unique reactor system in the treatment of these wastes. The reactor utilises proton-exchange membrane technology to eliminate the requirement of conductivity in treated waste streams; thus the membrane serves as a solid electrolyte. The reactor system has therefore been referred to as a solid-polymer-electrolyte reactor. Novel metal oxide anodes are responsible for the oxidation of the organic molecules. These metal oxide catalysts show promise in the treatment of a wide variety of organic wastes. A SnO2 catalyst doped with ZrO2 is used as anode in this study. Dopants are added to the catalyst to improve properties such as catalytic activity and conductivity. Kinetic data was obtained on a wide range of values for the chosen experimental parameters (current density and flow rate). Phenol, an organic molecule often referred to in the literature as model contaminant due to its resistance to oxidation,was also used as contaminant in this study. The use of the reactor system in the disinfection of water containing selected pathogens, were included in the experimental work. This kinetic data served in the development of a simple model of the process, and provided the basis for a full analysis regarding potential scale-up and economic feasibility. A requirement of the study was the accurate determination of the various oxidation breakdown products of phenol. This led to the refinement of an HPLC analytical method in order to quantitatively determine these products. The full analysis showed that the current reactor system would not be economically viable — mainly due to very long reactor lengths required for the complete removal of all organic material. Both mass transfer and charge transfer at the chosen experimental conditions influenced the electrochemical oxidation of phenol. High pressure drops, causing low flow rates in the reactor, accounted for this because of the narrow flow channels required in the reactor. Some catalyst deactivation was also suspected to affect the overall reaction, but the full extent of the deactivation was not investigated thoroughly. There is still room for improvement in the electrochemical oxidation of organic wastes. The design of the flow channels, a factor that was not investigated, can significantly improve efficiency. Another aspect that was not investigated was the catalyst type. The catalyst has been identified in the literature as the main contributing factor to the success of the oxidation reaction. A wide variety of metal oxide catalysts are currently being researched and may improve the kinetics of the process even further. Further improvement needs to be made on the membrane/electrode assembly to improve current density distribution. Every improvement of the process in terms of the reactor design and catalyst will impact on the economics of the process, thus making the process more competitive with current treatment technologies.
AFRIKAANSE OPSOMMING: In die afgelope paar dekades, is daar ’n wye verskeidenheid metodes ontwikkel wat gebruik kan word om industri¨ele afvoer strome te behandel. Hierdie ontwikkeling het plaasgevind as gevolg van die verhoogde eis aan skoner afvoerstrome. Wateragtige afvoerstrome wat organiese verbindings bevat, is van besonderse belang omdat hierdie tipe strome soms besonders moeilik kan wees om te behandel. Gebruiklike metodes is in die meeste gevalle ongeskik vir behandelings-doeleindes. Katalitiese oksidasie is sedert die 1960’s gebruik, maar hierdie prosesse benodig dikwels ho¨e drukke en temperature om suksesvol te wees. Elektrochemiese oksidasie het intussen ’n populˆere behandelingsmetode geword, aangesien die aktiveringsenergie vir die oksidasieproses hoofsaaklik afhanklik is van die aangewende potensiaal en dus kan die proses by atmosferiese toestande gebruik word. In hierdie tesis word die geskiktheid van ’n unieke reaktorstelsel vir water-suiwering ondersoek. Die reaktor gebruik ’n proton-uitruilings-membraan om die behoefte vir konduktiwiteit in die water uit te skakel. Die membraan dien dus as ’n tipe soliede elektroliet en as gevolg hiervan word na die reaktorstelsel verwys as ’n soliede-polimeer-elektroliet reaktor. Nuwe metaal-oksied anodes word in die reaktor gebruik aangesien hulle belowende resultate toon in die oksidasie van organiese verbindings. In die navorsing, is ’n SnO2 katalis wat klein hoeveelhede ZrO2 bevat gebruik. Oksiede soos ZrO2 word dikwels gebruik om die aktiwiteit en konduktiwiteit van hierdie kataliste te bevorder. Kinetiese data is oor ’n wye bereik van parameter waardes ingesamel. Die hoof parameters in die eksperimentele werk was stroom digtheid en vloeitempo. Fenol, ‘n komponent wat volgens die literatuur in hierdie tipe van werk gebruik word, isas die besoedelende komponent gekies. Die doeltreffendheid van die reaktor in die ontsmetting van water, wat met ’n verskeidenheid skadelike mikro-organismes besmet is, is ook getoets. ‘n Eenvoudinge model is opgestel m.b.v. die kinetiese data, waarna ’n volledige analise met betrekking tot grootskaalse bedryf en ekonomiese uitvoerbaarheid gedoen is. ‘n Vereiste van die studie was om die konsentrasie van die afbreek-produkte van die oksidasie akkuraat vas te stel. As gevolg hiervan is ‘n ho¨e-druk-vloeistofchromatografie analitiese metode verfyn. Die analise het getoon dat die reaktorstelsel nie ekonomies sou wees nie. Een van die hoofredes hiervoor is die onrealistiese reaktorlengtes wat benodig sou word. Resultate het getoon dat die reaksie deur beide massa-oordrag en lading-oordrag be¨ınvloed word. Ho¨e drukvalle in die reaktor wat gelei het tot lae vloeitempo’s was hiervoor verantwoordelik. Die deaktivering van die katalis be¨ınvloed waarskynlik die reaksie, maar die deaktiveringsverskynsel is nie ten volle ondersoek nie. Die reaktorstelsel kan verder verbeter word deur verskeie elemente van die reaktor te ondersoek. Die ontwerp van die vloeikanale in die reaktor is nie ondersoek nie en kan die werksverrigting van die reaktor verhoog. Uit die literatuur is gevind dat die tipe metaaloksied wat as katalis gebruik word, die reaksie direk be¨ınvloed. Dus kan navorsing wat tans op die kataliste gedoen word nuwe kataliste na vore bring wat meer doeltreffend sal wees. Laastens, is die huidige membraan/elektrode samestelling nog oneffektief en kan die reaktor-opstelling dus nog verbeter word. Elke verbetering wat op die bogenoemde faktore van die reaktor ontwerp verkry word, sal die ekomoniese uitvoerbaarheid van die proses be¨ınvloed. So, sal die proses al meer kompeterend met huidige behandelingsmetodes word.
37
Pokethitiyook, Prayad. "Nitrate utilization as the final electron acceptor in a biological phosphorus removal system". Thesis, This resource online, 1990. http://scholar.lib.vt.edu/theses/available/etd-03122009-040836/.
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Hijazi, Amal. "Nitrogen and phosphorus transformations in fixed-film biofilters subjected to aeration/no-aeration cycles". Thesis, Queensland University of Technology, 1998. https://eprints.qut.edu.au/36070/6/36070_Digitised_Thesis.pdf.
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Despite recent developments in fixed-film combined biological nutrients removal (BNR) technology; fixed-film systems (i.e., biofilters), are still at the early stages of development and their application has been limited to a few laboratory-scale experiments. Achieving enhanced biological phosphorus removal in fixed-film systems requires exposing the micro-organisms and the waste stream to alternating anaerobic/aerobic or anaerobic/anoxic conditions in cycles. The concept of cycle duration (CD) as a process control parameter is unique to fixed-film BNR systems, has not been previously investigated, and can be used to optimise the performance of such systems. The CD refers to the elapsed time before the biomass is re-exposed to the same environmental conditions in cycles.
Fixed-film systems offer many advantages over suspended growth systems such as reduced operating costs, simplicity of operation, absence of sludge recycling problems, and compactness. The control of nutrient discharges to water bodies, improves water quality, fish production, and allow water reuse. The main objective of this study was to develop a fundamental understanding of the effect of CD on the transformations of nutrients in fixed-film biofilter systems subjected to alternating aeration I no-aeration cycles A fixed-film biofilter system consisting of three up-flow biofilters connected in series was developed and tested. The first and third biofilters were operated in a cyclic mode in which the biomass was subjected to aeration/no-aeration cycles. The influent wastewater was simulated aquaculture whose composition was based on actual water quality parameters of aquacuture wastewater from a prawn grow-out facility. The influent contained 8.5 - 9:3 mg!L a111monia-N, 8.5- 8.7 mg/L phosphate-P, and 45- 50 mg!L acetate. Two independent studies were conducted at two biofiltration rates to evaluate and confirm the effect of CD on nutrient transformations in the biofilter system for application in aquaculture: A third study was conducted to enhance denitrification in the system using an external carbon- source at a rate varying from 0-24 ml/min. The CD was varied in the range of0.25- 120 hours for the first two studies and fixed at 12 hours for the third study.
This study identified the CD as an important process control parameter that can be used to optimise the performance of full-scale fixed-film systems for BNR which represents a novel contribution in this field of research. The CD resulted in environmental conditions that inhibited or enhanced nutrient transformations. The effect of CD on BNR in fixed-film systems in terms of phosphorus biomass saturation and depletion has been established. Short CDs did not permit the establishment of anaerobic activity in the un-aerated biofilter and, thus, inhibited phosphorus release.
Long CDs resulted in extended anaerobic activity and, thus, resulted in active phosphorus release. Long CDs, however, resulted in depleting the biomass phosphorus reservoir in the releasing biofilter and saturating the biomass phosphorus reservoir in the up-taking biofilter in the cycle. This phosphorus biomass saturation/depletion phenomenon imposes a practical limit on how short or long the CD can be. The length of the CD should be somewhere just before saturation or depletion occur and for the system tested, the optimal CD was 12 hours for the biofiltration rates tested.
The system achieved limited net phosphorus removal due to the limited sludge wasting and lack of external carbon supply during phosphorus uptake. The phosphorus saturation and depletion reflected the need to extract phosphorus from the phosphorus-rich micro-organisms, for example, through back-washing. The major challenges of achieving phosphorus removal in the system included: (I) overcoming the deterioration in the performance of the system during the transition period following the start of each new cycle; and (2) wasting excess phosphorus-saturated biomass following the aeration cycle. Denitrification occurred in poorly aerated sections of the third biofilter and generally declined as the CD increased and as the time progressed in the individual cycle. Denitrification and phosphorus uptake were supplied by an internal organic carbon source, and the addition of an external carbon source (acetate) to the third biofilter resulted in improved denitrification efficiency in the system from 18.4 without supplemental carbon to 88.7% when the carbon dose reached 24 mL/min The removal of TOC and nitrification improved as the CD increased, as a result of the reduction in the frequency of transition periods between the cycles. A conceptual design of an effective fixed-film BNR biofilter system for the treatment of the influent simulated aquaculture wastewater was proposed based on the findings of the study.
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Loemker, Rabea. "Nutrient removal in a constructed wetland treating urban stormwater runoff". Thesis, Queensland University of Technology, 2002. https://eprints.qut.edu.au/36156/1/36156_Loemker_2002.pdf.
Pełny tekst źródłaStreszczenie:
Urban stormwater runoff is a major concern in Australia and in other parts of the world, because of its potential severe, quantity and quality related impacts on the
health of environmental water systems. Many stormwater quality improvement devices (SQ IDs) have been developed over time. Constructed wetlands are a relatively new SQID, and are the specific topic of this thesis. The construction of wetlands for stormwater quality improvement has been prompted by the effectiveness of natural wetlands in storing stormwater runoff
during rainfall events and improving water quality during flow through the system
during dry periods. However, like other ecosystems, wetlands are profoundly complex. Wetlands for stormwater quality improvement vary greatly in performance
due to differences in design, climate, catchment characteristics and other factors. In particular, nutrient removal efficiencies vary widely among wetland systems. This is a result of the lack of understanding of fundamental aspects of these extremely complex, heterogeneous systems, and of phenomena responsible for nutrient removal. In particular how these are affected by environmental conditions and
system design.
This thesis investigated the performance of a constructed wetland treating
stormwater runoff from an urban catchment. It aims to improve understanding of the performance of wetlands in removing nutrients from stormwater runoff, in a
subtropical climate. A three-year-old wetland system (Keith Boden wetland) located in an urban
catchment in Brisbane, Australia, was investigated over two distinct seasonal periods, autumn and summer. Water samples were collected at eight locations in
different parts of the wetland. Additionally, sediment samples were taken on the last sampling date of the autumn sampling period. Results from this study showed that this wetland system was most effective and
consistent in removing nitrate and orthophosphate during both seasons (autumn and summer). However, concentrations of both nitrate and orthophosphate were considerably lower within the wetland during summer. The removal of nitrate was mainly due to denitrification. The removal process for orthophosphate varied within the two sampling periods: Biological uptake of orthophosphate appeared to be high during the summer period. The processes of orthophosphate retention during the autumn sampling period were more difficult to understand and it was more likely that uptake of orthophosphate was overshadowed by the release of orthophosphate from the sediments. Other forms of nitrogen and phosphorus that were measured displayed variable behaviour within the wetland system. During summer vertical temperature and dissolved oxygen profiling showed stratification on some occasions.
A detailed discussion of the methodology and results of this study highlighted the complexity of wetland systems and showed that any study of these systems is
necessarily limited. Nonetheless, the experimental studies conducted as a part of this research have provided insights into the systems functioning and greater awareness of possible behaviours. This is important knowledge to aid the monitoring, design
and application of wetlands as SQIDs.
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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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Pattarkine, Vikram Madhao. "The role of metals in enhanced biological phosphorus removal from wastewater". Diss., This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-08082007-120247/.
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Kendrick, Martin. "Algal bioreactors for nutrient removal and biomass production during the tertiary treatment of domestic sewage". Thesis, Loughborough University, 2011. https://dspace.lboro.ac.uk/2134/8944.
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This thesis covers work carried out on algae bioreactors as a tertiary treatment process for wastewater treatment. The process was primarily assessed by the removal of Phosphorus and Nitrogen as an alternative to chemical and bacterial removal. Algal bioreactors would have the added advantage of carbon sequestration and a by-product in the energy rich algal biomass that should be exploited in the existing AD capacity. Laboratory scale bioreactors were run (4.5-30L) using the secondary treated final effluent from the local Loughborough sewage works. In a preliminary series of experiments several different bioreactor designs were tested. These included both batch feed and continuous flow feed configurations. The bioreactors were all agitated to keep the algal cells in suspension. The results demonstrated that the most effective and easy to operate was the batch feed process with the algal biomass by-product harvested by simple gravitational settling. Experiments also compared an artificial light source with natural light in outdoor experiments. Outdoor summer light produced greater growth rates but growth could not be sustained in natural UK winter light. Light intensity is proportional to productivity and algae require a minimum of around 97W/m2 to grow, an overcast winter day (the worst case scenario) was typically around 78W/m2, however this was only available for a few hours per day during Nov-Jan. The process would be better suited to areas of the world that receive year round sunlight. It was shown that phosphorus could be totally removed from wastewater by the algae in less than 24 hours depending on other operating variables. With optimisation and addition of more carbon, a HRT of 10-12 hours was predicted to achieve the EU WFD / UWWTD standard. It was further predicted that the process could be economically and sustainably more attractive than the alternatives for small to medium sized works. Biomass 3 concentrations of between 1-2g/L were found to best achieve these removals and produce the fastest average growth rates of between 125-150mg/L/d. The uptake rates of phosphorus and nitrogen were shown to be dependent on the type of algae present in the bioreactor. Nitrogen removal was shown to be less effective when using filamentous bluegreen algae whilst phosphorus removal was almost completely stopped compared to unicellular green algae that achieved a nitrogen uptake of 5.3mg/L/d and phosphorus uptake of 8mg/L/d. Soluble concentrations of Fe, Ni and Zn were also reduced by 60% in the standard 10 hours HRT. The predominant algae were shown to depend largely on these concentrations of phosphorus and nitrogen, and the strain most suited to that specific nutrient or temperature environment dominated. Nutrient uptake rates were linked to algal growth rates which correlated with the availability of Carbon as CO2. CO2 was shown to be the limiting factor for growth; becoming exhausted within 10 hours and causing the pH to rise to above 10.5. The literature showed this was a common result and the use of CO2 sparging would more than double performance making this process a good candidate for waste CO2 sequestration. Heat generated from combustion or generators with exhaust CO2 would also be ideal to maintain a year round constant temperature of between 20-25°C within the bioreactors. A number of possible uses for the algal biomass generated were examined but currently the most feasible option is wet anaerobic co-digestion. Further economic analysis was recommended on the balance between land area and complementary biomass generation for AD. It was also suggested given the interest as algae as a future fuel source, the process could also be adapted for large scale treatment and algal biomass production in areas of the world where land was available.
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Kaschula, Wendy A. "The effect of alternative detergent builders on the nutrient removal activated sludge sewage treatment process". Master's thesis, University of Cape Town, 1993. http://hdl.handle.net/11427/8454.
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Includes bibliography.Phosphate is an essential nutrient for photosynthetic plant growth. However if over-supplied in a water body, it leads to excessive algal growth, a condition is termed eutrophication. Eutrophication is not only unsightly, but renders the water less usable. Most of the highly eutrophied water bodies with a high phosphorus load still receive up to 90 of their phosphorus input from effluents discharged by sewage treatment works (Pretorius, 1983). The phosphorus content of domestic sewage originates from two main sources, namely human waste {±60) and detergents {±40) (Heynike and Wiechers, 1986). There is an argument for a ban on phosphate in detergents to reduce the phosphate load on sewage treatment plants and thereby limit phosphate discharges via treated municipal effluent. The removal of phosphate from detergent formulations has been an effective way in many countries of reducing the phosphorous load to receiving waters. In South Africa, detergent manufacturers are anticipating consumer pressure to reformulate their detergent products to eliminate phosphate. The two possible replacements for phosphates are zeolite 4A and high surface area {HSA) calcite. High surface area (SA) calcite is not yet being used as a detergent builder, but is being seriously considered as a potential replacement for phosphate in South African detergent formulations.
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Beard, Kelly Marie. "Role of oxidants in the removal of iron and organics from Harwood's Mill Reservoir". Thesis, Virginia Polytechnic Institute and State University, 1985. http://hdl.handle.net/10919/104292.
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Lin, Chung-Ho. "Bioremediation capacity of five forage grasses for Atrazine, Balance (Isoxaflutole) and nutrient removal /". free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3052192.
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46
Hart, Vincent S. "An examination of biological phosphorus removal using bacterial counting and poly-β-hydroxybutyrate analysis in batch and continuous flow systems". Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/40652.
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The objective of this study was to examine excess biological phosphorus removing bacterial populations and their substrate utilization mechanisms. This study was a smaller part of a overall study of temperature effects upon excess biological phosphorus removal.
Bacterial populations in both a continuous flow UCT (University of Cape Town) system and batch reactors were examined by direct counting using a well known staining procedure (Neisser staining), and a microscopic counting method developed by Cech and Hartman (1993). Substrate utilization was examined using PHB (Poly-β -Hydroxybutyrate - an internal substrate storage product) analysis by gas chromatography to supplement COD and acetate measurements.
The results showed that Poly-P bacterial counts were significantly greater at a 5 day sludge age compared to a 10 day sludge age. It was noted from microscopic observations that the size of the poly-phosphate granules in the bacteria seemed to be a better indicator of system performance than the actual counts. It also was observed that the 'G' bacteria first described by Cech and Hartman (1993) were abundant at the 10 day sludge age but completely absent at the 5 day sludge age.
PHB storage occurred in both the anaerobic zone and the first aerobic tank, and PHB utilization was seen in the subsequent aerobic tanks of the UCT system. The formation of PHB in the first aerobic reactor when no substrate was available supports the Mino (1987) model for excess biological phosphorus removal.
In batch studies, substrate storage release were demonstrated in the aerobic zone. This explained why when acetate was present in the aerobic zone net phosphorus uptake didn't occur until all the acetate was utilized.
When the temperature was lowered in the UCT system nitrification ceased. This resulted in soluble COD breakthrough into the aerobic zone, which stimulated filamentous growth, and eventually caused a lack of PHB formation. All of these factors contributed to a loss of excess biological phosphorus removal at the low temperature.Master of Science
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Hanson, Carter Curtis. "Temporal effect on nitrogen removal in a subsurface flow constructed wetland". Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1027117.
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A subsurface flow constructed wetland planted with the common reed (Phragmites australis) and softstem bulrush (Scirpus validus) was built in East Central Indiana. The objective of this study was to determine if temperature had an effect on nitrogen (N) removal from the wetland. The research was conducted from the first week of October 3, 1995 to the first week in December 5, 1995 why the wetland froze. Water samples were taken from 5 samplings sites in the system. Each sample was analyzed for organic-N, ammonia, nitrate, and total-N. In the system statistically significant amounts of organic-N, nitrate, and total-N were removed. Ammonia lever reductions, however, were not significant. Organic-N had a mean removal of 37% (8 mg/1) 'Nitrate had a mean removal of 96% (2.3 mg/1). Total-N removal over the sampling period averaged 30% (12 mg/1). The N results were regressed against air and wastewater temperatures. Wastewater temperature was more important because it had a direct impact can the plants and microbes in the system. Warmer temperatures sustained a higher metabolism for the biota in the system. Air temperature had an indirect impact on efficiency of N removal from the wastewater flowing through the wetland. The primary impact .: f the air temperature was on water temperature which then affected the metabolism of or a nc ns in the wetland cell. Greater removal efficiencies were seen during high temperature periods and lower removal efficiencies were noted when the temperatures were low.Department of Natural Resources and Environmental Management
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Grobbelaar, Loreen. "Treatment of biodiesel wastewater in a hybrid anaerobic baffled reactor microbial fuel cell (ABR-MFC) system". Thesis, Cape Peninsula University of Technology, 2019. http://hdl.handle.net/20.500.11838/2812.
Pełny tekst źródłaStreszczenie:
Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2019.The biodiesel industry produces large volumes of biodiesel wastewater (BDWW) during the purification of crude biodiesel. This wastewater is characterised by high concentrations of chemical oxygen demand (COD), biological oxygen demand (BOD), total suspended solids (TSS), and fats, oils and greases (FOG) which in turn defines BDWW as a highly polluted effluent. The low nitrogen and phosphorous content of BDWW creates an unfavourable environment for the growth of microorganisms, thereby making it difficult to degrade naturally. Biodiesel companies discharge untreated non-compliant wastewater directly to the municipal sewer system. Treatment prior to discharge is a necessity since the disposal of untreated BDWW may raise serious environmental concerns (i.e. disturbance of biological ecosystems) resulting in penalties liable by non-compliant companies due to the implementation of the waste discharge charge system (WDCS) which is regulated by the industrial waste discharge standard limits in South Africa (SA). This study aimed to combine the advantages of the conventional anaerobic baffled reactor (ABR) system with microbial fuel cell (MFC) technology resulting in an innovative technology used to treat high strength industrial BDWW at ambient conditions. Many studies have reported effective treatment of BDWW, however to date literature implementing an ABR equipped with MFC technology has not been reported. The main objectives of the study were to determine which parameters do not meet the industrial wastewater discharge standard limits, whether pH and carbon:nitrogen:phosphorous (C:N:P) ratio adjustments will suffice prior to treatment with the ABR-MFC, the maximum power density (PD) as well as to determine the treatment efficiency of the ABR-MFC.
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Hsu, Chung-Jung. "The removal of phenols from oily wastewater by chlorine dioxide". Thesis, Virginia Tech, 1988. http://hdl.handle.net/10919/45159.
Pełny tekst źródłaStreszczenie:
Treatability studies were performed on oily wastewaters produced by petroleum
and canning industries.
Chlorine dioxide was used for the removal of phenolic compounds from these oily wastewaters. Most of phenolic compounds can be destroyed by chlorine dioxide within 15 minutes if CI02-to-phenol ratios of higher than 5.0 are provided. Factors such as pH, temperature, and COD have little effect on phenol removal.
The effectiveness of chlorine dioxide treatment depends critically on the performance
of the chlorine dioxide generator. High yields of chlorine dioxide generation
can be achieved by maintaining the pH between 2.5 and 3.5, and by
controlling the concentration of feed chemicals.
For small treatment plants, chlorine dioxide treatment may be an economical
process because no expensive equipment is required.
Master of Science
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Nash, Jeffrey William. "Characteristics and conditioning of anaerobically digested sludge from a biological phosphorus removal plant". Thesis, Virginia Tech, 1989. http://hdl.handle.net/10919/44128.
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A study of the anaerobically digested sludge form a
full-scale biological phosphorus removal (BPR) plant (York
River Wastewater Treatment Plant, York River, Va.) was
conducted to determine the effects of BPR on sludge
characteristics and conditioning requirements. Data
collected from the plant indicated that both the total and
soluble phosphorus (P) concentrations in the anaerobically
digested sludge increased dramatically with the initiation
of BPR. Accompanying this increase in total P was an
increase in the total concentrations of magnesium and
potassium content of the sludge, supporting the observations
that these ions are coâ transported with P during the
accumulation and release of P by P accumulating organisms.
The majority of the phosphate present in the pre- and post-
BPR anaerobically digested sludges was bound by calcium,
magnesium, and iron phosphorus precipitates including
hydroxyapatite, struvite, and vivianite. Calcium phosphorus
precipitates were the most prevalent in both sludges, but
the percentage of magnesium phosphorus precipitates
increased with the onset of BPR.
Cationic organic polymer conditioning dosages needed to
achieve acceptable sludge dewatering rates for the post-BPR
sludge were similar to those required by the pre-BPR sludge.
The cationic organic polymer used to condition these sludges
was ineffective in removing excess phosphate; therefore, the
addition of either one or both of the inorganic chemicals
ferric chloride and calcium hydroxide was required to remove
soluble phosphorus. Conditioning with either ferric
chloride or calcium hydroxide alone was not effective in
achieving acceptable dewatering rates; however, when used
together the chemicals produced acceptable dewatering rates
and soluble P removal from the post-BPR sludge.Master of Science