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1
Atayol, Ahmet Avni Sofuoğlu Aysun. "Anaerobic co-treatability of olive mill wastewaters and domestic wastewater/". [s.l.]: [s.n.], 2003. http://library.iyte.edu.tr/tezler/master/cevremuh/T000239.pdf.
Testo completo
2
Wang, Y. "Wastewater minimisation and the design of wastewater treatment systems". Thesis, University of Manchester, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.488391.
Testo completo
3
Pan, Xiaodi. "Radioisotopes in Domestic Wastewater and Their Fate in Wastewater Treatment". Digital WPI, 2016. https://digitalcommons.wpi.edu/etd-theses/1247.
Testo completoAbstract (sommario):
"Modern medical therapies involving radioisotopes provide radionuclide contamination in wastewater. These radioisotopes present in wastewater increase the possibility of human exposure to radiation. The objective of this work was to study the fate of radionuclides of medical sources in wastewater, and to determine the distribution of various radionuclides in different stages of wastewater treatment. Influent, return activated sludge and effluent samples were collected from four wastewater facilities in Massachusetts. Samples were collected approximately twice a month over 4 months. The radionuclides and their decay products were tested by inductively coupled plasma with mass spectrometry (ICP-MS) and broad energy germanium detector analysis (BEGe). The samples were analyzed to determine the content and radioactivity of each target radionuclide and decay product for three treatment stages (influent, return activated sludge and effluent) from each facility at different sampling times. The results indicated that I-131 is the only radionuclide in wastewater, however many decay products were identified. Recommendations are put forward according to the testing results."
4
Fain, Norm. "Wastewater - A Resource". Arizona-Nevada Academy of Science, 1991. http://hdl.handle.net/10150/296459.
Testo completoAbstract (sommario):
From the Proceedings of the 1991 Meetings of the Arizona Section - American Water Resources Association and the Hydrology Section - Arizona-Nevada Academy of Science - April 20, 1991, Northern Arizona University, Flagstaff, ArizonaAs the Southwest United States grows and develops, one basic resource becomes a primary necessity for survival: Water. Currently, accepted sources are being consumed at a higher rate than nature replenishes them. This is necessitating the need to find and develop new water resources. In conjunction with the proper treatment and management, wastewater is a water resource, known as reuse. Properly managed, reused water can augment the available water supply. Primary applications include irrigation of agricultural and landscaped areas, surface water recreational areas, and groundwater recharge. These uses relieve the demands on the generally accepted water resources, thus increasing the net water supply. The required level of treatment varies with the intended reuse application. Treatment levels for reuse range from secondary to tertiary treatment systems. Some reuse applications provide additional treatment to the water. The reuser must assure that the treatment system and reuse application provide an equal or improved water quality to that of the receiving body of water. Regardless of the application, stringent operation and maintenance of the reuse system is essential. A well planned management program will minimize hazards associated with reuse of wastewater. This program is required to keep the liabilities of both the treatment plant and reuse site owners to a minimum. Without this, reuse is not a viable option. The underlying questions remain to determine the feasibility of reuse for a community: Does the water supply require augmentation to meet the demands of the future? Is the Owner willing to address and implement a diligent system management program?
5
Palmquist, Helena. "Hazardous substances in wastewater systems : a delicate issue for wastewater management". Licentiate thesis, Luleå tekniska universitet, 2001. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-17510.
Testo completoAbstract (sommario):
Many substances derived from human activity end up in wastewater systems at some point. A large number of different substances - up to 30,000 - are present in wastewater. Some of them are valuable, such as nitrogen and phosphorus, but there are also hazardous substances such as heavy metals and anthropogenic organic substances. To be able to utilise the wastewater nutrients on arable land (agriculture, forestry or other alternatives), it is of great importance to investigate the sources of hazardous substances in wastewater and the human activities and attitudes that brings these different substances into the wastewater systems. For management of wastewater residues it is therefore important to be able to assess both the benefits and the risks from such products. Residues from wastewater are complex mixtures of substances, which demand a multi-sided approach for solving the problem as a whole.Godkänd; 2001; 20070225 (ysko)
6
Heimel, Daniel Eric. "Anaerobic Co-digestion of Wastewater Treatment Pond Algae with Wastewater Sludge". DigitalCommons@CalPoly, 2010. https://digitalcommons.calpoly.edu/theses/440.
Testo completoAbstract (sommario):
Microalgae harvested from wastewater treatment ponds can be anaerobically digested to produce biogas, a renewable fuel resource. However, past experiments have shown some limitations of algae digestion. Algal cell walls are thought to be resistant to digestion, and the high protein content of algae can lead to ammonia toxicity in digesters. Co-digestion of algae with substrates containing higher C:N ratios (e.g., waste paper) can be used to maintain non-inhibitory ammonia concentrations and increase methane production. However, high carbon waste co-substrates have become costly or are not readily available in many communities. Although domestic wastewater sludge has only a marginally higher C:N ratio than algae biomass, sludge is a practical co-substrate for treatment pond facilities using primary sedimentation. The present laboratory research evaluated the use of wastewater sludge as a co-substrate with treatment pond algae that were harvested by coagulation and dissolved air flotation. The research was meant to assist in the planning for full-scale algae digestion at a large pond facility in California. The independent variables evaluated were algae/sludge ratio in the digester feed (100% to 0%), organic loading rate (OLR; 2 or 4 g volatile solids/L-d), and hydraulic residence time (HRT; 20 or 40 d), while the main dependent variables were methane yield, volumetric methane production, and the dewaterability of the digester effluents. Co-digestion of algae with sludge was stable, with healthy pH, at all algae/sludge ratios with OLRs up to 4 g volatile solids loaded per liter digester per day (g VS/L-d) at a 20-d HRT. For digesters fed algae biomass exclusively, at a 2 g VS/L-d OLR and a 20-d HRT, the methane yield was 0.26 L/g VS-d and methane productivity was 0.52 g VS/L digester-d. A control digester fed sludge exclusively, with the same loading rate, produced more methane: the yield was 0.44 L/g VS-d and production was 0.87 L/L-d. No significant synergistic benefit in algae methane yield was observed due to co-digestion with wastewater sludge. The effluent from digesters fed only algae dewatered as effectively or better than digesters fed only wastewater sludge. However, freezing of the algae biomass prior to digestion could have affected the results. An engineering model was developed to estimate heating requirements and net electricity production for full-scale algae digesters. For two example climates (Mediterranean and continental desert), the model predicted that despite the lower methane production of algae digestion, heat recovered from cogeneration and electricity generation would be more than sufficient to fulfill the inputs required for algae digestion. For facultative pond wastewater treatment facilities with existing collection and digestion of primary sludge, addition of the algae produced to the digesters is expected to increase electricity production by 120%.
7
Burgess, Joanna E. "Micronutrients for wastewater treatment". Thesis, Cranfield University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323932.
Testo completo
8
Malandra, Lida 1975. "Biodegradation of winery wastewater". Thesis, Stellenbosch : University of Stellenbosch, 2003. http://hdl.handle.net/10019.1/16385.
Testo completoAbstract (sommario):
Thesis (MSc)--University of Stellenbosch, 2003.ENGLISH ABSTRACT: Large volumes of wastewater are generated annually during the grape harvest season from various processing and cleaning operations at wineries, distilleries and other wine-related industries. South African regulatory bodies dictate that wastewater should have a pH of 5.5 to 7.5 and a chemical oxygen demand (COD) lower than 75 mg/L. However, winery wastewater has a typical pH of 4 to 5 and a COD varying between 2 000 and 12 000 mg/L. Urban wineries channel the wastewater to local sewage treatment facilities and are often heavily fined for exceeding governmental requirements. Rural wineries usually have little or no treatment operations for their wastewater and it is often irrigated onto crops, which may result in environmental pollution and contamination of underground water resources. Various criteria are important in choosing a wastewater treatment system, such as an ecofriendly process that is flexible to withstand various concentration loads and characteristics, requiring low capital and operating costs, minimal personal attention and do not require too much land. In this study, a large variation in COD, pH and chemical composition of the winery wastewater was observed that could be related to varying factors such as the harvest load, operational procedures and grape variety. Wastewater from destemming and pressing operations contained higher concentrations of glucose, fructose and malic acid, which originated from the grape berries. The fermentable sugars (glucose and fructose) contributed to almost half of the COD with a smaller contribution from ethanol and acetic acid. The low pH can be ascribed to relative high concentrations of organic acids in the wastewater. The efficacy of biological treatment systems depends strongly on the ability of microorganisms to form biofilm communities that are able to degrade the organic compounds in the wastewater. Preliminary identification of microorganisms that naturally occur in winery wastewater indicated the presence of various bacterial and yeast species that could be effective in the biological treatment of the wastewater. When evaluated as pure cultures under aerobic conditions, some of the yeast isolates effectively reduced the COD of a synthetic wastewater, whereas the bacterial isolates were ineffective. The most effective yeast isolates were identified as Pichia rhodanensis, Kloeckera apiculata, Candida krusei and Saccharomyces cerevisiae. Our search for cost-effective biological treatment systems led to the evaluation of a Rotating Biological Contactor (RBC) for the treatment of winery wastewater. The RBC was evaluated on a laboratory scale with 10% (v/v) diluted grape juice and inoculated with a mixed microbial community isolated from winery wastewater. The results showed a reduction in the COD that improved with an extended retention time. Evaluation of the RBC on-site at a local winery during the harvest season resulted on average in a 41% decrease in COD and an increase of 0,75 pH units. RFLP analysis of the biofilm communities within the RBC confirmed a population shift in both the bacterial and fungal species during the evaluation period. The most dominant yeast isolates were identified with 18S rDNA sequencing as Saccharomyces cerevisiae, Candida intermedia, Hanseniaspora uvarum and Pichia membranifaciens. All these species are naturally associated with grapes and/or water and with the exception of Hanseniaspora uvarum, they are able to form either simple or elaborate pseudohyphae.
AFRIKAANSE OPSOMMING: Groot hoeveelhede afloopwater word jaarliks gedurende die druiwe-oestyd deur verskeie prosessering- en skoonmaakoperasies deur wynkelders, distilleer- en ander wynverwante industrieë gegenereer. Suid-Afrikaanse beheerliggame vereis dat afloopwater ‘n pH van 5.5 tot 7.5 en ‘n chemiese suurstofbehoefte (COD) van minder as 75 mg/l moet hê. Kelderafloopwater het egter gewoonlik ‘n pH van 4 tot 5 en ‘n COD van 2 000 tot 12 000 mg/L. Stedelike wynkelders voer die afloopwater na ń plaaslike rioolsuiweringsaanleg wat dikwels tot swaar boetes vir oortreding van die wetlike vereistes lei. Plattelandse wynkelders het gewoonlik min of geen behandelingsprosesse vir hul afloopwater nie en gebruik die water dikwels vir gewasbesproeiing, wat tot omgewingsbesoedeling en kontaminasie van ondergrondse waterbronne kan lei. Verskeie kriteria is belangrik in die keuse van ‘n waterbehandelingstelsel, byvoorbeeld ‘n omgewingsvriendelike proses wat verskillende konsentrasieladings en samestellings kan hanteer, ‘n lae kapitaal- en bedryfskoste en minimale persoonlike aandag vereis en min ruimte benodig. Hierdie studie het getoon dat kelderafloopwater ‘n groot variasie in COD, pH en chemiese samestelling het wat met wisselende faktore soos die oeslading, operasionele prosesse en selfs die druifkultivar verband kan hou. Afloopwater van ontstingeling- en parsoperasies het hoër konsentrasies glukose, fruktose en appelsuur wat van die druiwekorrels afkomstig is. Die fermenteerbare suikers (glukose en fruktose) dra tot amper 50% van die COD by, met ‘n kleiner bydrae deur etanol en asynsuur. Die lae pH kan grootliks aan organiese sure in die afloopwater toegeskryf word. Die effektiwiteit van biologiese behandelingstelsels steun sterk op die vermoë van mikroorganismes om biofilmgemeenskappe te vorm wat die organiese verbindings in die afloopwater kan afbreek. Voorlopige identifikasie van mikro-organismes wat natuurlik in wynafloopwater voorkom, het die teenwoordigheid van verskeie bakteriese en gisspesies aangedui. Evaluering van hierdie isolate onder aërobiese toestande het getoon dat sommige van die gis-isolate die COD van ‘n sintetiese afloopwater effektief kon verlaag, terwyl die bakteriese isolate oneffektief was. Die mees effektiewe gis-isolate is as Pichia rhodanensis, Kloeckera apiculata, Candida krusei en Saccharomyces cerevisiae geïdentifiseer. Ons soektog na ‘n koste-effektiewe biologiese behandelingsisteem het tot die evaluering van ‘n ‘Rotating Biological Contactor’ (RBC) vir die behandeling van afloopwater gelei. Die RBC is op laboratoriumskaal met 10% (v/v) verdunde druiwesap geëvalueer en met ‘n gemengde mikrobiese gemeenskap wat uit afloopwater geïsoleer is, innokuleer. Die resultate het ‘n verlaging in die COD getoon wat met ‘n langer retensietyd verbeter het. Evaluering van die RBC by ‘n plaaslike wynkelder gedurende die oesseisoen het gemiddeld ‘n verlaging van 41% in die COD en ‘n verhoging van 0,75 pH eenhede getoon. RPLP analise van die biofilmgemeenskappe in die RBC het ‘n bevolkingsverskuiwing in beide die bakteriese en swamspesies aangetoon. Die mees dominante gisspesies is met 18S rDNA volgordebepaling as Saccharomyces cerevisiae, Candida intermedia, Hanseniaspora uvarum en Pichia membranifaciens geïdentifiseer. Al hierdie spesies word gewoonlik met druiwe en/of water geassosieer en is, met die uitsondering van Hanseniaspora uvarum, in staat om òf eenvoudige òf komplekse pseudohife te vorm.
9
Veijola, T. (Tommi). "Domestic wastewater heat recovery". Bachelor's thesis, University of Oulu, 2017. http://urn.fi/URN:NBN:fi:oulu-201704271600.
Testo completoAbstract (sommario):
The aim of this thesis is to study and explain the purpose and the function of drain water heat exchangers. The thesis goes over theory behind heat transfer and heat exchangers and presents the general solutions of domestic drain water heat recovery systems. Systems gone over in detail are the different general shower drain water heat recovery systems.
Another part of the thesis is a case study of an actual shower drain water heat recovery system of a Finnish household. The purpose of the case study is to study the actual temperature increase of cold water in a drain water heat recovery unit and efficiency of such heat exchanger. An alternate goal is to study the difference in efficiency values and temperature gains between two heat exchangers of the same model, where the other has been used significantly more than the other. In other words, another target is to study the fouling effect. The calculations are done using real measurement data.
The most important findings are that utilizing a shower drain heat recovery unit provides real energy savings in the long run, and that there is a significant difference of efficiency between a dirty and a clean heat exchanger. Drain water heat recovery systems provided as high as 15 °C increase in the temperature of cold water. A clean heat exchanger boasts an impressive 50.4% efficiency, whereas the dirtier heat exchanger provides a 36.1% efficiency. The results can be further used to calculate the energy savings of the household on a yearly basis. Furthermore, the results show that domestic drain water heat recovery could potentially make a significant difference in national energy usage if implemented nationwide.
10
Abdel-Halim, Walid Sayed. "Anaerobic municipal wastewater treatment /". Hannover : Inst. für Siedlungswasserwirtschaft und Abfalltechnik, 2005. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=014189251&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Testo completo
11
Hassinger, Elaine, e Jack Watson. "Treatment of Household Wastewater". College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 1998. http://hdl.handle.net/10150/146293.
Testo completoAbstract (sommario):
2 pp.Almost all farm houses use a septic tank system or similar on-site wastewater system to treat household wastewater. These systems are usually economical and safe. But, they must be able to safely handle all wastewater produced by your household and must treat wastewater adequately to prevent contamination of groundwater and surface water. This publication lists several questions to help you determine whether your household wastewater treatment system may pose a risk to your groundwater.
12
Rowse, John William. "A framework for comparison of on-site wastewater management and centralised wastewater management". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0021/MQ54579.pdf.
Testo completo
13
Nilsson, Peter. "Infiltration of wastewater : an applied study on treatment of wastewater by soil infiltration /". Lund, Sweden : Dept. of Environmental Engineering, Lund Institute of Technology, University of Lund, 1990. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=006106905&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Testo completo
14
Mbulawa, Siyasanga. "Bio-delipidation of pre-treated poultry slaughterhouse wastewater by enzymes from the wastewater isolates". Thesis, Cape Peninsula University of Technology, 2017. http://hdl.handle.net/20.500.11838/2743.
Testo completoAbstract (sommario):
Thesis (Master of Engineering in Chemical Engineering)--Cape Peninsula University of Technology, 2017.Pre-treatment of wastewater such as that from poultry slaughterhouses, which contains fats, oil,and grease (FOG) is necessary prior to the primary biological treatment of the wastewater to meet legislated discharge standards and to prevent environmental pollution. Physico- chemical pre-treatment is often applied to remove FOG in poultry slaughterhouse wastewater (PSW) before biological treatment. These pre-treatment methods, in particular physical pre- treatment systems, use synthetic chemicals, known to cause environmental contamination challenges, with FOG being inefficiently removed in certain instances. Biological techniques such as bio-delipidation using enzymatic catalysis for the pre-treatment of FOG-laden PSW could enhance the efficiency of the downstream biological treatment processes. This research focused on further bio-delipidation of PSW pre-treated with a dissolved air flotation system (DAF) for FOG removal using microbial lipases from bacterial strains isolated from the PSW itself. Bacterial strains (n = 2) isolated from the PSW and screened for their potential to produce lipases were found to have a higher bio-delipidation potential when compared to other isolates (n = 18). Both isolates were identified using 16s rRNA as Bacillus sp., i.e. both Bacillus cereus AB1 (BF3) and CC-1 (B3O). These isolates were used to produce lipases, whereby are sponse surface methodology (RSM) was used to optimise pH (4-8) and temperature (30-60°C) as critical production conditions. achieving an optimum lipase production was achieved, with activity of 11.25 U/mL at 60°C, a pH of8 for BF3, and 15.50U/mL at 45°C and pH of 8.8 for B3O respectively, after 72 hours of bioreactor operation. The enzymes produced from both isolates were partially purified using a Bio-Rad size exclusion chromatography column (Bio-Gel® P-60) prior to use in subsequent experiments. The presence and activity of lipase were further determined using p-nitrophenyl acetate (p- NPA) as a substrate with the functionality of the semi-purified enzymes being characterized by optimizing the conditions in which the enzymes were required to function. Lipase activity was enhanced by Mg2+ while Fe2+, Na+, K+, Ca2+ were observed to have an inhibitory effect on the enzymes from both strains. Similarly, reduced stability of the lipases in organic solvents, namely toluene, methanol, and isopropanol, was also established. Additionally, detergents, Triclosan (TCS) (5-chloro-2-(2,4-dichlorophenoxy-phenol) and trichlorocarbonilide (3,4,4- trichlorocarbonilide)(TCC), usually found in PSW as antimicrobial and disinfectant agents to sanitise poultry product processing facilities, were used assess the activity of the enzyme in their presence at a concentration of 30% (v/v) (although these anti- microbial agents are used in minute quantities in cleaning products). The lipases from isolate BF3 maintained an activity of 91.43% and 81.36% in the presence of TCS and TCC, while that of B3O enzyme had 85.32% and 73.91% acitivity, when compared to the reference (control) experiments. The bio-delipidation efficacy was studied under varying pH and temperature conditions using DAF pre-treated PSW, observing a further removal efficiency of fatty acids from the protein- laden PSW at different pH and temperature. Bio-delipidation was found to be largely influenced by pH, as a pH below 7 and above 10 at 40°-45°C, calculated in the bio- delipidation efficiency reduction to below 50%. The temperature range mentioned, i.e 40°- 45°C, had a positive effect on further deffating of the protein-rich DAF pre-treated PSW, as high removal efficiency was observed at this temperature range. This could be due to the characteristic of the enzymes used,or the formation of stable FOG agglomerates and/oremulsion. Overall, a DAF effluent containing residual FOG and proteins was bio-delipidated effectively using enzymes from the PSW isolates, achieving further removal of FOG and proteins by 64.35% to 80.42%, culminating in tCOD reduction and reduced PSW turbidity, further resulting in improved wastewater quality characteristics meeting disposal standards. This study demonstrated that sequential DAF pre-treated PSW bio-delipidation has the potential to enhance the efficiency of downstream biological anaerobic treatment processes for PSW by further reducing residual FOG from a DAF system.
15
Catlin, Rachael. "Decolourization of yeast manufacturing wastewater /". [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe.pdf.
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16
Whitton, Rachel Louise. "Algae reactors for wastewater treatment". Thesis, Cranfield University, 2016. http://dspace.lib.cranfield.ac.uk/handle/1826/10289.
Testo completoAbstract (sommario):
The onset of the Water Framework Directive (WFD) will challenge water utilities to further reduce their wastewater phosphorus discharges to < 0.5 mg.L- 1. Whilst conventional treatments, such as chemical dosing, are able to meet these new discharge consents, the strategies are representative of a linear economy model where resources are unrecovered and disposed. An alternative solution which can contribute to the aspiration of a circular economy is microalgae. Microalgae are ubiquitous in wastewater environments and assimilate phosphorus during their growth, to residual concentrations complementary of the WFD. Furthermore, microalgal biomass can be anaerobically digested to produce biomethane offering the potential for an energy neutral approach. However, uptake of microalgal systems are lacking in the UK through limited knowledge of operation; and the belief that such solutions are synonymous to large, shallow open ponds with extensive treatment times. The development of alternative microalgal reactors are increasingly investigated to overcome these implementation challenges. Of these, immobilised microalgae has shown great potential; and whilst within its infancy demonstrates the greatest opportunity for development and optimisation. This thesis determines the critical operational parameters that influence the remediation efficacy of immobilised microalgae for tertiary nutrient removal; including species selection, biomass concentration, treatment period and lighting; with recommendations for optimal performance. These recommendations are then applied to the design and operation of an immobilised bioreactor (IBR) to understand the key design and operating components that influence the overall economic viability. In doing so, the potential for an IBR to be economically viable, within the next decade, in comparison to traditional approaches are discussed.
17
Palmquist, Helena. "Hazardous substances in wastewater management /". Luleå, 2004. http://epubl.luth.se/1402-1544/2004/47.
Testo completo
18
Leclair, Christine. "Ozonation of sulfamethoxazole in wastewater". Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=99776.
Testo completoAbstract (sommario):
Many studies have demonstrated that sewage treatment plants do not efficiently degrade pharmaceuticals such as antibiotics, hormones, and analgesics. Ozonation has been identified as a promising technique to degrade those compounds. A series of experiments was used to evaluate the impact of three parameters on the efficiency and kinetics of degradation of sulfamethoxazole, an antibiotic, by ozonation. An ozone reactor was designed to perform experiments. Analytical techniques, based on liquid and gas chromatography and mass spectrometry, were developed to measure concentrations of sulfamethoxazole and identify degradation products.It was shown that the rate constant and the degradation efficiency are greater when the initial concentration of sulfamethoxazole is lower; the presence of other contaminants in solution decreases the percentage of degradation observed, and the concentration of hydrogen peroxide, used as catalyst, must be well adjusted since an inappropriate concentration hinders the reaction. Finally, the analysis of ozonated samples allowed the identification of degradation products and resulted in a proposed degradation mechanism.
19
Gambrill, Martin Peter. "Physicochemical treatment of tropical wastewater". Thesis, University of Leeds, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.237255.
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20
Meehan, Colette. "Biotreatment of textile industry wastewater". Thesis, University of Ulster, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.232842.
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21
Thomas, David N. "Flocculation modelling in wastewater treatment". Thesis, Cranfield University, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.323835.
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22
REIS, RONALD DA SILVA. "TREATEMENT WASTEWATER EFFLUENTS CONTAINING HYDRAZINE". PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2003. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=5112@1.
Testo completoAbstract (sommario):
No Brasil está em larga expansão o uso de geração de
eletricidade por termoeléctricas. Na geração de
eletricidade por usinas térmicas são utilizados grandes
quantidades de água e produtos químicos, que após
utilização geram efluentes. A hidrazina é um produto
químico usado para controle de corrosão em águas de
caldeiras, sistemas de vapor e outros sistemas de usinas
térmicas que após utilização acaba incorporada aos
efluentes líquidos destas usinas. Com intuito de promover
uma sistemática de controle de efluentes produzidos nas
usinas, procurou-se, nesta dissertação, estudar efluentes
contendo hidrazina com enfoque tecnológico. O processo
abordado neste estudo consistiu no tratamento de efluentes
contendo hidrazina, utilizando peróxido de hidrogênio com
auxílio de catalisador de íons de cobre, para decomposição
da hidrazina. Os ensaios foram feitos em laboratório,
utilizando-se efluentes sintéticos com concentrações pré-
determinadas de hidrazina que variaram entre 10 e 100 mg/L,
com controle do pH que variou em 7 e 9,5, temperatura
fixada em 220C, com adição de concentrações calculadas de
peróxido de hidrogênio e catalisador de sulfato de cobre.
Concluiu-se que o processo é viável para reduzir a
concentração de hidrazina em efluentes a níveis inferiores
aos limites da legislação (1 mg/L), utilizando-se
quantidades estequiométricas de peróxido de hidrogênio em
conjunto com sulfato de cobre em concentrações de 1 mg/L de
Cu 2+ como catalisador, em efluentes com pH 9,5, a
temperatura ambiente, em tempos inferiores a 30 minutos.
Assim sendo, o trabalho mostrou-se adequado para satisfazer
as condições de descarte de efluentes em águas brasileiras
de acordo com a resolução CONAMA 20, carta P-031/01
cláusula 2 artigo V, de 9 de Fevereiro de 2001.In Brazil, the use of energy produced by power plant generators is in expansion. Power plants use large quantities of water and chemical products that after use end up in effluents. Hydrazine is used in water systems for corrosion control, because of its excelents oxygen scavenging capacity. The present work was conducted to study the treatment of effluents containing hydrazine, under a technological approach, with the purpose of contributing to a systematic of effluents control in power stations. The process studied in this work was the decomposition of hydrazine with hydrogen peroxid in presence catalyst cooper íon. The experiments were made in laboratory scale, using synthetic effluents with initial concentration of hydrazine at the levels 10 and 100 mg/L, with initial pH values 7 and 9,5, temperature fixed at 220C, with addition of st oichiometric amounts of hydrogen peroxide, with and without addition of cooper ion catalyst. It was conclued that the process its viable for reduction of hydrazine concentration in effluents with pH 9,5, below to levels under legislation (1mg/L), using stoichiometric amounts of hydrogen peroxide together with 1 mg/L of cooper ion, in times less that 30 minutes and ambient temperature. Therefore this work showed that the process is adequate in satisfying the Brazilian legislation for discharge of effluents into water bodies according to regulation CONAMA 20, letter P-031/01 clause 2 article V, 09 February 2001.
23
Peterson, Mark. "Electrodisinfection of Municipal Wastewater Effluent". ScholarWorks@UNO, 2005. http://scholarworks.uno.edu/td/294.
Testo completoAbstract (sommario):
To avoid the spread of disease from sewage treatment effluents, pathogenic microorganisms present must be destroyed by one or a combination of disinfection methods. Chlorine remains the predominant disinfectant used although it consumes considerable amounts of energy and has associated exposure risks from production, transportation and storage of this poisonous gas. In addition to bacteria and other objectionable microorganisms, color, suspended and colloidal solids also require removal from water for reuse. Aluminum and iron additions have been used to coagulate and remove non-settleable solids. By electrically dissolving aluminum to form solids-bridging aluminum hydroxide, the water itself can also be disinfected by the effects of electrical fields and its reactions to form disinfectant chemicals and direct destruction of microorganisms in the water. This research investigated the effects of electrical current, time, and chloride concentration on the electrochemical disinfection of sewage treatment plant effluent using aluminum electrodes to substitute for chlorine disinfection.
24
Blazo, Christopher. "Wastewater Disinfection with HYDROFLOW Technology". ScholarWorks@UNO, 2013. http://scholarworks.uno.edu/td/1611.
Testo completoAbstract (sommario):
Disinfection is the final and very important step of wastewater treatment to maintain healthy ecosystems. Although chlorination is the most prevalent wastewater disinfection method, there are serious safety concerns and ecological problems associated with its use. The purpose of this study was to test the feasibility of using a HydroFLOW 60i unit for wastewater disinfection, as an alternative to chlorination. The study was performed using two different reactors, namely, a bench-scale laboratory batch reactor, and a continuous flow, pilot unit. Using the batch reactor, it was found out that the HydroFLOW 60i unit is effective to kill bacteria; however, modifications to this mode of operation would be required in order to increase the disinfection efficiency and to decrease the detention time. When the continuous flow system was run using a hydraulic detention time of 10 minutes and a single pass through the HydroFLOW unit, the E. coli removal efficiency was negligible. Further research is needed to determine the most economical and efficient reactor configuration in order to make the HydroFLOW unit competitive with conventional wastewater chlorination.
25
Morris, William Raymond. "Enteroviruses in water and wastewater". Thesis, University of Surrey, 1986. http://epubs.surrey.ac.uk/847825/.
Testo completoAbstract (sommario):
Procedures for the detection of cytopathic enteroviruses in the water cycle were assessed. A method was developed and applied to a wide range of field samples. It depended upon concentration of viruses by adsorption to epoxy-bound fibre-glass filter tubes with subsequent elution of viruses with beef extract solution. Viruses were further concentrated by organic flocculation and infectivity assayed by a suspended cell plaque method using BGM cells. Cytopathic enteroviruses, limited to serotypes of polioviruses, coxsackie group B viruses and echoviruses, were isolated from treated and untreated potable waters, surface waters, raw sewages and wastewater effluents. The relationships of physicochemical and bacteriological pollutants to viral contamination were examined and indicated that as levels of bacteria rose the likelihood of viruses also being present increased. However, the correlation was poor because viruses were found in the absence of indicator bacteria and conversely. The virological quality of the Severn and Trent river catchments revealed that two tributaries, the river Stour and the river Tame, were the major sources of viral pollution in each catchment respectively. Storage of river waters, destined for further treatment as drinking water, for at least fifty days resulted in significant reductions of the numbers of viruses. Similarly, long-term lagooning of wastewater effluents resulted in a substantial decline in virus titres. The value of other forms of wastewater treatment, sedimentation, activated sludge, percolating filtration and sand filtration, effected unpredictable reductions of virus numbers. The case for surveillance of virus levels in the water cycle is stressed.
26
Sabienski, Lina. "Characterization of microplastics in wastewater". Thesis, Örebro universitet, Institutionen för naturvetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:oru:diva-86249.
Testo completoAbstract (sommario):
This study aims to detect how many microplastics and what kind are released from the wastewater treatment plant (WWTP) Skebäck, in Örebro. The study was limited to the analysis of three filters with 50 μm mesh size and one filter with 300 μm mesh size. The samples were taken at different times, two in the fall of 2019 and one in the spring of 2020. Visual characterization was used for the quantification of microplastics, and a lower and upper bound was used. The lower bound represents particles that were deemed identifiable as plastic with high certainty, while the upper bound also includes particles that may have been microplastic. An additional ATR-FTIR analysis was performed on selected microplastics >300 μm. The presence of microplastics in the effluent from Skebäcks WWTP could be confirmed. The quantity of microplastics per m3 (MP/m3) trapped on the 50 μm filters were quantified in a range between 0 MP/m3 to 291 MP/m3 for the lower bound, and 72 MP/m3 to 435 MP/m3 for the upper bound. The 300 μm filter had considerably less microplastics than the 50 μm filter with 1.8 MP/m3. The quantification of fibers on the 50 μm filter and 300 μm filters was not possible due to high blank contaminations. According to the concentration of 63 MP/m3 of the lower bound count on the 50 μm filters and the amount of water flowing through Skebäck in 2019, 17 818 935 m3, 1.1 billion microplastic particles were released into Svartån that year. In comparison the highest value of the upper bound count, 435 MP/m3, gave a release of 7.7 billion microplastic particles. Using the concentration of the 300 μm filter 1.8 MP/m3, 32 million microplastics/year were released from Skebäck in 2019. The amount of spheres 50-300 μm released in the effluent from Skebäck was estimated to be 3.7 kg in 2019.
27
Chalivendra, Saikumar. "Bioremediation of Wastewater Using Microalgae". University of Dayton / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=dayton1418994496.
Testo completo
28
Medley, Gareth. "Microbubble generation for wastewater treatment". Thesis, University of Sheffield, 2015. http://etheses.whiterose.ac.uk/8493/.
Testo completo
29
Ross, Michael Eric. "Wastewater treatment by filamentous macroalgae". Thesis, University of Edinburgh, 2018. http://hdl.handle.net/1842/31512.
Testo completoAbstract (sommario):
An increase in anthropogenic activity has led to the heightened levels of pollution entering aquatic systems. These excessive concentrations of heavy metals, nitrogen (N), and phosphorus (P) in water bodies can lead to several adverse impacts, such as eutrophication and human health risks. Therefore, the removal of pollutants from wastewaters, prior to their discharge into the natural environment, is of paramount importance. However, conventional wastewater treatment (WWT) technologies have their limitations; for instance, large capital/operational costs, and incomplete removal of contaminants. Therefore, innovative and more effective treatment technologies are required. Macro-algae typically have high growth and solar energy conversion rates, and are able to sequester nutrients, utilise CO2, and adsorb metals from aquatic environments. Therefore, algae may have potential applications in WWT. Furthermore, costs could be negated by the production of renewable algal biomass which may have a variety of commercially exploitable applications. However, issues such as poor selection of species or cultivation systems, and a lack of understanding of the influence of biological, chemical and physical factors, particularly in a highly dynamic wastewater environments, has led to varied results and prevented algal WWT becoming a widespread reality. In this thesis the algae Cladophora coelothrix and Cladophora parriaudii were studied as potential organisms for implementation into WWT. In addition to the features mentioned above, Cladophora was selected due to its ubiquity, filamentous morphology, which minimises harvesting costs, as well as their natural dominance and bloom forming behaviour in nutrient-rich environments. The influence of dewatering techniques, environmental factors, and nutrient regime upon the growth, nutrient/metal removal, and biochemical composition of the biomass were assessed. The first aspect of the thesis was an abiotic screening process, in order to investigate the robustness of Cladophora and its suitability for WWT applications on a fundamental level. Good rates of growth (4-13.3% d-1) and nutrient removal (45.2-99.9%) were observed throughout the screening process, except under the most extreme of conditions, e.g. pH 3. This indicated that Cladophora are potentially suitable for treating a broad range of wastewaters and merit further research to improve its potential applicability for WWT applications and commercial realisation. For instance, developing a reliable and accurate method for fresh weight (FW) assessment and hence productivity estimation. The determination of growth rate via FW measurement is one of the most basic aspects of algal biology, yet no standardised method exists for filamentous macro-algae. A variety of FW methods were systematically assessed in terms of accuracy and physiological impact. Methods involving mechanical pressing to dewater the biomass resulted in >25% reduction in the final biomass yield, compared to control cultures. The best method for FW determination employed a reticulated spinner, which was rapid, reliable, and easily standardised. Furthermore, this approach ensured accurate growth estimation with minimal physiological impact, measured as growth, maintenance of structural integrity and nutrient removal. This indicates that the method developed has the potential for widespread application in macro-algal cultivation, as such the method was employed throughout this thesis. The influence of nutrient regime on growth, biochemical composition, and bioremediation capacity was studied for both species of Cladophora. The nutrient regimes tested, representative of a broad variety of wastewaters, included four different N/P ratios, four N sources (ammonium, nitrate, nitrite and urea), and six different equimolar N source combinations provided at two N/P ratios. There were clear differences in performance between the two species, with higher rates of growth observed in all instances by C. parriaudii (4.75-11.2% d-1 vs. 3.98-7.37% d-1). Furthermore, ammonium was removed preferentially, whereas urea was removed secondarily. However, the presence of urea in the medium enhanced growth and uptake of the other co-existing N-forms, and yielded a carbohydrate-rich biomass (37.6-54% DW). These findings demonstrate that algal strain selection is important for treating wastewaters with specific nutrient profiles. In addition, results from this study suggest that nutrient regimes can be tailored to produce biomass with certain properties or characteristics, which make it suitable for further, potentially commercially viable, applications, such as metal biosorption. Since the biochemical characteristics of algal biomass were shown to be affected by nutrient regime, the final chapter describes research investigating the influence of nutritional history on metal biosorption. C. parriaudii was cultivated under different nutrient regimes to produce biomass of varying biochemical composition. This biomass was then used for metal removal, with maximum removal rates ranging from 1.08-2.35 mmol g1, 0.3-0.62 mmol g-1, 0.22-0.48 mmol g-1, and 0.43-0.61 mmol g-1 for Al2+, Cu2+, Mn2+, and Pb2+, respectively. Observations from this work indicate that metal removal is achieved by various mechanisms including adsorption, ion exchange, complexation and micro-precipitation, and that the biosorption efficacy is dependent upon the number and type of functional groups present, which are in turn influenced by the cultures nutrient regime. Overall, this study demonstrates the inter-relatedness of biological, chemical, and physical factors on algal growth, nutrient removal, biochemical composition, and metal biosorption. Results from this work have highlighted the need for standardisation in protocols, increased understanding of the influence of algal selection and nutrient characteristics in bioremediation, and highlighted the importance of considering biological aspects, specifically nutritional history, in biosorption studies.
30
Ugarelli, Rita Maria <1973>. "Asset management of wastewater networks". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/878/1/Tesi_Ugarelli_Rita_Maria.pdf.
Testo completoAbstract (sommario):
Asset Management (AM) is a set of procedures operable at the strategic-tacticaloperational
level, for the management of the physical asset’s performance, associated
risks and costs within its whole life-cycle. AM combines the engineering, managerial and
informatics points of view. In addition to internal drivers, AM is driven by the demands of
customers (social pull) and regulators (environmental mandates and economic
considerations). AM can follow either a top-down or a bottom-up approach.
Considering rehabilitation planning at the bottom-up level, the main issue would be to
rehabilitate the right pipe at the right time with the right technique. Finding the right pipe
may be possible and practicable, but determining the timeliness of the rehabilitation and
the choice of the techniques adopted to rehabilitate is a bit abstruse. It is a truism that
rehabilitating an asset too early is unwise, just as doing it late may have entailed extra
expenses en route, in addition to the cost of the exercise of rehabilitation per se. One is
confronted with a typical ‘Hamlet-isque dilemma’ – ‘to repair or not to repair’; or put in
another way, ‘to replace or not to replace’. The decision in this case is governed by three
factors, not necessarily interrelated – quality of customer service, costs and budget in the
life cycle of the asset in question.
The goal of replacement planning is to find the juncture in the asset’s life cycle where the
cost of replacement is balanced by the rising maintenance costs and the declining level of
service. System maintenance aims at improving performance and maintaining the asset
in good working condition for as long as possible. Effective planning is used to target
maintenance activities to meet these goals and minimize costly exigencies.
The main objective of this dissertation is to develop a process-model for asset
replacement planning. The aim of the model is to determine the optimal pipe replacement
year by comparing, temporally, the annual operating and maintenance costs of the
existing asset and the annuity of the investment in a new equivalent pipe, at the best
market price. It is proposed that risk cost provide an appropriate framework to decide the
balance between investment for replacing or operational expenditures for maintaining an
asset.
The model describes a practical approach to estimate when an asset should be replaced.
A comprehensive list of criteria to be considered is outlined, the main criteria being a visà-
vis between maintenance and replacement expenditures. The costs to maintain the
assets should be described by a cost function related to the asset type, the risks to the
safety of people and property owing to declining condition of asset, and the predicted
frequency of failures. The cost functions reflect the condition of the existing asset at the
time the decision to maintain or replace is taken: age, level of deterioration, risk of failure.
The process model is applied in the wastewater network of Oslo, the capital city of
Norway, and uses available real-world information to forecast life-cycle costs of
maintenance and rehabilitation strategies and support infrastructure management
decisions. The case study provides an insight into the various definitions of ‘asset lifetime’
– service life, economic life and physical life. The results recommend that one common
value for lifetime should not be applied to the all the pipelines in the stock for investment
planning in the long-term period; rather it would be wiser to define different values for
different cohorts of pipelines to reduce the uncertainties associated with generalisations
for simplification.
It is envisaged that more criteria the municipality is able to include, to estimate
maintenance costs for the existing assets, the more precise will the estimation of the
expected service life be. The ability to include social costs enables to compute the asset
life, not only based on its physical characterisation, but also on the sensitivity of network
areas to social impact of failures.
The type of economic analysis is very sensitive to model parameters that are difficult to
determine accurately. The main value of this approach is the effort to demonstrate that it
is possible to include, in decision-making, factors as the cost of the risk associated with a
decline in level of performance, the level of this deterioration and the asset’s depreciation
rate, without looking at age as the sole criterion for making decisions regarding
replacements.
31
Ugarelli, Rita Maria <1973>. "Asset management of wastewater networks". Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2008. http://amsdottorato.unibo.it/878/.
Testo completoAbstract (sommario):
Asset Management (AM) is a set of procedures operable at the strategic-tacticaloperational
level, for the management of the physical asset’s performance, associated
risks and costs within its whole life-cycle. AM combines the engineering, managerial and
informatics points of view. In addition to internal drivers, AM is driven by the demands of
customers (social pull) and regulators (environmental mandates and economic
considerations). AM can follow either a top-down or a bottom-up approach.
Considering rehabilitation planning at the bottom-up level, the main issue would be to
rehabilitate the right pipe at the right time with the right technique. Finding the right pipe
may be possible and practicable, but determining the timeliness of the rehabilitation and
the choice of the techniques adopted to rehabilitate is a bit abstruse. It is a truism that
rehabilitating an asset too early is unwise, just as doing it late may have entailed extra
expenses en route, in addition to the cost of the exercise of rehabilitation per se. One is
confronted with a typical ‘Hamlet-isque dilemma’ – ‘to repair or not to repair’; or put in
another way, ‘to replace or not to replace’. The decision in this case is governed by three
factors, not necessarily interrelated – quality of customer service, costs and budget in the
life cycle of the asset in question.
The goal of replacement planning is to find the juncture in the asset’s life cycle where the
cost of replacement is balanced by the rising maintenance costs and the declining level of
service. System maintenance aims at improving performance and maintaining the asset
in good working condition for as long as possible. Effective planning is used to target
maintenance activities to meet these goals and minimize costly exigencies.
The main objective of this dissertation is to develop a process-model for asset
replacement planning. The aim of the model is to determine the optimal pipe replacement
year by comparing, temporally, the annual operating and maintenance costs of the
existing asset and the annuity of the investment in a new equivalent pipe, at the best
market price. It is proposed that risk cost provide an appropriate framework to decide the
balance between investment for replacing or operational expenditures for maintaining an
asset.
The model describes a practical approach to estimate when an asset should be replaced.
A comprehensive list of criteria to be considered is outlined, the main criteria being a visà-
vis between maintenance and replacement expenditures. The costs to maintain the
assets should be described by a cost function related to the asset type, the risks to the
safety of people and property owing to declining condition of asset, and the predicted
frequency of failures. The cost functions reflect the condition of the existing asset at the
time the decision to maintain or replace is taken: age, level of deterioration, risk of failure.
The process model is applied in the wastewater network of Oslo, the capital city of
Norway, and uses available real-world information to forecast life-cycle costs of
maintenance and rehabilitation strategies and support infrastructure management
decisions. The case study provides an insight into the various definitions of ‘asset lifetime’
– service life, economic life and physical life. The results recommend that one common
value for lifetime should not be applied to the all the pipelines in the stock for investment
planning in the long-term period; rather it would be wiser to define different values for
different cohorts of pipelines to reduce the uncertainties associated with generalisations
for simplification.
It is envisaged that more criteria the municipality is able to include, to estimate
maintenance costs for the existing assets, the more precise will the estimation of the
expected service life be. The ability to include social costs enables to compute the asset
life, not only based on its physical characterisation, but also on the sensitivity of network
areas to social impact of failures.
The type of economic analysis is very sensitive to model parameters that are difficult to
determine accurately. The main value of this approach is the effort to demonstrate that it
is possible to include, in decision-making, factors as the cost of the risk associated with a
decline in level of performance, the level of this deterioration and the asset’s depreciation
rate, without looking at age as the sole criterion for making decisions regarding
replacements.
32
WAHID, MARFIAH BINTI AB. "OCCURRENCE AND REDUCTION OF PATHOGENS IN WASTEWATER TREATMENT AND CONSIDERATION FOR WASTEWATER RECLAMATION AND REUSE". 京都大学 (Kyoto University), 2011. http://hdl.handle.net/2433/151968.
Testo completo
33
Curran, Daniel Thomas. "Phosphate Removal and Recovery from Wastewater by Natural Materials for Ecologically Engineered Wastewater Treatment Systems". ScholarWorks @ UVM, 2015. http://scholarworks.uvm.edu/graddis/455.
Testo completoAbstract (sommario):
Eutrophication due to excess loading of phosphorus (P) is a leading cause of water quality degradation within the United States. The aim of this study was to investigate P removal and recovery with 12 materials (four calcite varieties, wollastonite, dolomite, hydroxylapatite, eggshells, coral sands, biochar, and activated carbon. This was accomplished through a series of batch experiments with synthetic wastewater solutions ranging from 10-100 mg PO₄-P/ L. The results of this study were used to establish large-scale, calcite-based column filter experiments located in the Rubenstein School of Environment and Natural Resources' Eco-Machine. Influent and effluent wastewater samples were routinely collected for 64 days. Measures of filter performance included changes in pH, percent reduction and mass adsorbed of P. After the columns reached saturation, filter media was analyzed for the mineralogical content by X-ray powder diffraction (XRD).
In the batch experiments, P removal and recovery varied among the media and across treatments. The best performing minerals were calcite, wollastonite, and hydroxylapatite. Eggshells, activated carbon, and coral sands also reduced and adsorbed P. The remaining materials had the lowest reductions and adsorption of P.
Results from batch experiments informed the design of large column filters within the Rubenstein School of the Environment and Natural Resources' Eco-Machine. Removal and adsorption rates of P by the three column filters were similar. The columns achieved an average P reduction of 12.53% (se = 0.98) and an average P adsorption of 0.649 mg PO₄-P/ kg media (se = 0.03) over a 4-h hydraulic retention time. Paired T-tests showed that P reductions were statistically significant (p-value < 0.05) on the majority of sampling dates until the columns reached saturation. Saturation was reached after 31 days for two of the columns and 36 days for the third column. The filter media consistently buffered the pH of the wastewater to approximately 6.0-7.0 with no indication of diminishing buffer capacity after saturation. XRD analysis was not able to detect any P species within the crystalline structure of the filter media.
This research contributes to the understanding of how the selected media perform during P removal and recovery programs, while providing information on the performance of large column filters operating within advanced, ecologically engineered wastewater treatment systems.
34
Whiteleather, Stuart C. "An overview of wastewater privatization and the process behind privatizing the Lehigh County Wastewater Pretreatment facility". Instructions for remote access. Click here to access this electronic resource. Access available to Kutztown University faculty, staff, and students only, 1997. http://www.kutztown.edu/library/services/remote_access.asp.
Testo completoAbstract (sommario):
Thesis (M.P.A.)--Kutztown University of Pennsylvania, 1997.Source: Masters Abstracts International, Volume: 45-06, page: 2964. Abstract precedes thesis as preliminary leaves [1-2]. Typescript. Includes bibliographical references (leaves 72-73).
35
Petrini, Serena. "Insight into microalgal-bacterial consortia for sustainable wastewater treatment. Investigations at lab-scale with real wastewater". Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/264967.
Testo completoAbstract (sommario):
High costs for aeration, greenhouse-gas emissions and excess sludge disposal have entailed a paradigm shift in the wastewater treatment.
Microalgal-bacterial-based wastewater treatments have gained increasing attention because of their potential in energy demand reduction and biomass resource recovery. In particular, photosynthetic oxygenation is combined with bacterial activity to treat wastewater avoiding external artificial aeration. To optimize the technology in order to become more competitive than activated sludge, an in-depth investigation about the treatment performance and the microbiology interactions under real operational condition is needed.
This work focused on the study of wastewater-borne microalgal-bacterial consortia treating real municipal wastewater. The main objectives were to: (i) Understand the removal mechanisms and the influence of operational conditions to optimize the process; (ii) Analyze the microbial community. At first, a photo-sequencing batch reactor (PSBR), called Pilot, was started up and continuously monitored for two years to analyze the evolution of the treatment performance and of the biomass composition. At the same time, other two lab-scale PSBRs were installed to evaluate if microalgal inoculation is essential to start up a consortium. Samples of these consortia were collected over a period of one year and analyzed through microscopic observations, flow cytometry and metagenomics, to investigate the microbial structure and diversity.A second part of the research focused on the optimization of the Pilot to explore its limit in view of the scale-up of the system. In addition, respirometry was adapted to test microalgal-bacterial consortia to estimate the removal kinetic parameters for future modelling.
To conclude, the research project addressed many aspects and lay the foundation to apply a methodological research approach to scale-up this promising technology.
36
Petrini, Serena. "Insight into microalgal-bacterial consortia for sustainable wastewater treatment. Investigations at lab-scale with real wastewater". Doctoral thesis, Università degli studi di Trento, 2020. http://hdl.handle.net/11572/264967.
Testo completoAbstract (sommario):
High costs for aeration, greenhouse-gas emissions and excess sludge disposal have entailed a paradigm shift in the wastewater treatment.
Microalgal-bacterial-based wastewater treatments have gained increasing attention because of their potential in energy demand reduction and biomass resource recovery. In particular, photosynthetic oxygenation is combined with bacterial activity to treat wastewater avoiding external artificial aeration. To optimize the technology in order to become more competitive than activated sludge, an in-depth investigation about the treatment performance and the microbiology interactions under real operational condition is needed.
This work focused on the study of wastewater-borne microalgal-bacterial consortia treating real municipal wastewater. The main objectives were to: (i) Understand the removal mechanisms and the influence of operational conditions to optimize the process; (ii) Analyze the microbial community. At first, a photo-sequencing batch reactor (PSBR), called Pilot, was started up and continuously monitored for two years to analyze the evolution of the treatment performance and of the biomass composition. At the same time, other two lab-scale PSBRs were installed to evaluate if microalgal inoculation is essential to start up a consortium. Samples of these consortia were collected over a period of one year and analyzed through microscopic observations, flow cytometry and metagenomics, to investigate the microbial structure and diversity.A second part of the research focused on the optimization of the Pilot to explore its limit in view of the scale-up of the system. In addition, respirometry was adapted to test microalgal-bacterial consortia to estimate the removal kinetic parameters for future modelling.
To conclude, the research project addressed many aspects and lay the foundation to apply a methodological research approach to scale-up this promising technology.
37
Suopajärvi, T. (Terhi). "Functionalized nanocelluloses in wastewater treatment applications". Doctoral thesis, Oulun yliopisto, 2015. http://urn.fi/urn:isbn:9789526207797.
Testo completoAbstract (sommario):
Abstract The chemicals currently used for wastewater treatment are mainly based on synthetic inorganic or organic compounds. Oil-derived polyelectrolytes are used for the removal of colloidal solids from wastewater by flocculation and coagulation, for example, while activated carbon adsorbents are typically used to remove soluble impurities such as heavy metals and recalcitrance organic matter. Many of these chemicals have associated negative health impacts, and use of activated carbon has proved to be expensive. Moreover, the present synthetic chemicals are not readily biodegradable or renewable. Thus there is a high demand for “green” water chemicals which could offer a sustainable solution for achieving high-performance, cheap water purification. Water chemicals of a new type based on nano-scale particles (nanofibrils) derived from cellulose, i.e. nanocelluloses, are examined as possible bio-based chemicals for wastewater treatment. Two anionic nanocelluloses (dicarboxylic acid, DCC, and sulphonated ADAC) were tested as flocculants in the coagulation-flocculation treatment of municipal wastewater, while the flocculation performance of cationic nanocellulose (CDAC) was studied with model kaolin clay suspensions, and nanocelluloses produced from sulphonated wheat straw pulp fines (WADAC) were tested for the adsorption of lead (Pb(II)). The anionic nanocelluloses (DCC and ADAC) showed good performance in treating municipal wastewater in a combined coagulation-flocculation process with a ferric coagulant. In the case of both anionic nanocelluloses the combined treatment resulted in a lower residual turbidity and COD in a settled suspension with highly reduced total chemical consumption relative to coagulation with ferric sulphite alone. Likewise, the CDACs resulted in powerful aggregation of kaolin colloids and maintained effective flocculation performance over wide pH and temperature ranges. The capacity of the nanofibrillated and sulphonated fines cellulosics (WADAC) for the adsorption of Pb(II) was 1.2 mmol/g at pH 5, which is comparable to the capacities of commercial adsorbentsTiivistelmä Jätevesien kemiallinen käsittely pohjautuu pääsääntöisesti synteettisten epäorgaanisten ja orgaanisten kemikaalien käyttöön. Öljypohjaisia polyelektrolyytteja käytetään kolloidisten partikkeleiden poistamiseen jätevesistä koaguloimalla ja flokkuloimalla, kun taas liuenneita epäpuhtauksia, kuten raskasmetalleja, poistetaan useimmiten adsorboimalla ne aktiivihiileen. Synteettiset vesikemikaalit valmistetaan uusiutumattomista luonnonvaroista ja niiden hajoaminen luonnossa voi olla hidasta, minkä lisäksi monet näistä käytetyistä synteettisistä vesikemikaaleista ovat terveydelle haitallisia. Aktiivihiilen käyttö puolestaan on kallista, johtuen sen korkeista valmistus- ja käyttökustannuksista. Uusille ”vihreille vesikemikaaleille, jotka tarjoavat ympäristöystävällisempiä, halpoja sekä tehokkaita ratkaisuja vedenpudistukseen, onkin suuri kysyntä. Tässä työssä selluloosasta valmistettuja nanokokoisia partikkeleita, eli nanoselluloosia, on tutkittu yhtenä varteenotettavana biovaihtoehtona uusiksi kemikaaleiksi jätevesien puhdistukseen. Kahden anionisen nanoselluloosan (dikarboksyyli, DCC, ja sulfonoitu, ADAC) flokkauskykyä testattiin koagulointi-flokkulointi reaktioissa kunnallisen jäteveden puhdistuksessa. Kationisen nanosellun (CDAC) flokkauskykyä tutkittiin puolestaan kaoliinisaven malliliuoksilla ja vehnän korsisellun hienoaineista nanofibrilloimalla sekä sulfonoimalla valmistetuilla (WADAC) nanoselluloosamateriaaleilla testattiin lyijyn (Pb(II)) adsorptiota vesiliuoksista. Anioniset nanoselluloosat (DCC ja ADAC) toimivat tehokkaasti kunnallisen jäteveden flokkauksessa ferri-sulfaatin kanssa yhdistetyissä koagulointiflokkulointi reaktioissa. Yhdistetyissä reaktioissa molemmat anioniset nanoselluloosat vähensivät sameutta sekä COD pitoisuutta laskeutetuissa jätevesinäytteissä huomattavasti pienemmillä kemikaalikulutuksilla paremmin kuin pelkästään ferri-sulfaatilla koaguloitaessa. Myös CDAC:t toimivat tehokkaasti flokkauksessa keräten tehokkaasti kaoliinin kolloidipartikkeleita yhteen laajalla pH- ja lämpötila-alueella. Nanofibrilloidun ja sulfonoidun vehnäsellun hienoaineen (WADAC) adsorptiokapasiteetti lyijylle Pb(II) oli 1.2 mmol/g pH:ssa 5, mikä on verrannollinen kaupallisten adsorptiomateriaalien kapasiteettiin
38
Hamilton, Farideh. "Wastewater treatment using mineral-based materials". Thesis, University of Surrey, 2016. http://epubs.surrey.ac.uk/811343/.
Testo completoAbstract (sommario):
Human activities unintentionally add pollutants to water bodies. This research has focused on the removal of trace elements from sources of water pollution (point and non-point), using a mineral based by-product (Blueguard® solids). The materials were characterised to identify the mineralogy, structure, porosity, and composition using different techniques including X-ray Fluorescence Spectrometry, X-ray Powder Diffraction and Brunauer–Emmett–Teller gas sorption methods. The results showed that the main compounds of the Blueguard® materials are alteration products of Mg-rich silicates. Three different types of contaminated water originating from different sources were prepared and analysed. These samples included (a) a multi-element solution prepared from trace element stock solutions; (b) rain water contaminated with motorway dust, and (c) contaminated water taken from an industrially polluted site (Cranleigh Brickworks, Surrey). Trace element analysis was undertaken by inductively coupled plasma mass spectrometry. Using a batch equilibrium procedure with optimised conditions of 0.25 g material in 50 ml solution for 5 min contact time, the mixing of the Blueguard® materials with a multi-element solution showed an effective removal of various trace elements under pH 4 to 9 conditions. These materials were then used to treat contaminated rainwater mixed with digested motorway dust. Trace element removal occurred from 80% for manganese up to 100% for lead. Analysis of surface water samples collected from the Cranleigh Brickworks showed that the levels of zinc and manganese were above the World Health Organisation (WHO) guidelines for drinking water. The most contaminated lagoon (25950 µg l-1 Zn and 2843 µg l-1 Mn) on the site was selected for laboratory and on-site testing of the Blueguard® materials. The best removal efficiency for these types of materials took place under a static design system where more than 95% of zinc and up to 97% of manganese was removed. Further investigation of the Blueguard® materials suggested the mechanism by which these materials reduce the level of trace elements in a solution was by precipitation, as a result of pH increase (through release of OH-(aq)). The results obtained for metal removal at Cranleigh has resulted in the application of these materials to remediate the site.
39
O'Grady, Devin. "Biodegradation of 17alpha-ethinylestradiol in wastewater". Thesis, McGill University, 2007. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=18488.
Testo completoAbstract (sommario):
Pharmaceutical substances such as 17a-ethinylestradiol (EE2), the active component of contraceptive pill, are often not eliminated during wastewater treatment and are not biodegraded in the environment. In this Master's project, analytical techniques for analyzing the low concentration of EE2 during biodegradation were developed and the biodegradability of 17a-ethinylestradiol was studied using five bacteria. A preliminary identification of the produced metabolites was also completed. A low cost solid phase extraction (SPE) procedure was developed and optimized to obtain reproducible analyte recoveries in order to pre-concentrate the EE2 samples prior to HPLC analysis. The limit of analysis (LOA) was significantly lowered from 1.73 ppm to 0.173 ppm upon implementation of the combined SPE/HPLC method. R. erythropolis degraded EE2 up to 47% of its initial concentration in 13 h, while after 65 h, R. equi degraded EE2 up to 39% of its initial concentration. No significant EE2 degradation was observed using Rhodococcus rhodochrous and Rhodococcus zopfii. Preliminary analysis of EE2 degradation products confirmed the presence of phenol among other possible metabolites of high molecular weight.Plusieurs composés pharmaceutiques tel que le 17a-ethinylestradiol (EE2), l'ingrédient actif des contraceptifs oraux, ne sont pas efficacement éliminés lors du traitement des eaux usées et se biodégradent peu dans l'environnement. Au cours de ce projet de maîtrise, des techniques analytiques ont été développées afin de mesurer de faibles concentrations d'EE2 et la biodégradabilité d'EE2 a été étudiée en utilisant cinq types de bactéries. Une identification préliminaire des produits de dégradation a également été effectuée. Une méthode d'extraction en phase solide a été développée afin de préconcentrer les échantillons avant l'analyse par HPLC. L'optimisation de la méthode a permis d'obtenir une méthode reproductible offrant un haut pourcentage de récupération de l'analyte et ce, à faible coût. La préconcentration de l'échantillon a aussi permis de réduire la limite d'analyse par HPLC de 1.73 ppm à 0.173 ppm. R. erythropolis a dégradé jusqu'à 47% de la concentration initiale d'EE2 en 13 h, tandis qu'après 65 h, R. equi a engendré une dégradation atteignant 39% de la concentration initiale d'EE2. Aucune dégradation significative a été observée en utilisant R. rhodochrous et R. zopfii. Finalement, l'analyse préliminaire des produits de dégradation confirme la présence de phénol parmi d'autres produits de dégradation de poids moléculaires élevés.
40
Rodayan, Angela. "Ozonation of sulfamethoxazole in municipal wastewater". Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40763.
Testo completoAbstract (sommario):
Many pharmaceuticals, such as the antibiotic sulfamethoxazole, are not eliminated during a conventional wastewater treatment process and are often not biodegraded in the environment. In this project, 60 mg/L and 100 μg/L solutions of sulfamethoxazole in both reverse osmosis water and wastewater were treated with ozone. A solid phase extraction procedure with reproducible analyte recoveries was developed to pre-concentrate the low concentration of sulfamethoxazole in both water matrices (reverse osmosis and municipal wastewater). The wastewater matrix had no effect on the required ozone dose to reduce the concentration of sulfamethoxazole below the SPE-HPLC limit of detection. Solutions with an initial concentration of 60 mg/L required an ozone dose of 331 mg/L and eight peaks were detected throughout experiments. Solutions with an initial concentration of 100 μg/L required a dose of 55 mg/L and only four peaks were detected. Analysis of the degradation products showed that 4-aminobenzene sulfonamide, N-(3-phenylpropyl)-acetamide, 2-methyl-benzoxazole and phenol were present in both high and low concentration samples. In addition, methanol, ethanol, acetic acid, methyl acetate and ethyl acetate were present in the high concentration samples.Plusieurs pharmaceutiques, tel que l’antibiotique sulfaméthoxazole ne sont pas totalement éliminées lors du traitement des eaux usées et ne sont pas biodégradables dans l’environnent. Au cours de ce projet, deux types de solutions de sulfaméthoxazole ont été étudiées : à base d’eau traitée par osmose inverse et à base d’eau usée municipale. Des solutions ayant des concentrations de 60 mg/L et 100 μg/L ont été traitées par ozonation.Une méthode d’extraction en phase solide a été développée afin de préconcentrer les échantillons avant l’analyse par HPLC. Les solutions de sulfaméthoxazole composées d’eau traitée par osmose inverse et d’eau usée ont requis la même quantité d’ozone afin de réduire la concentration de sulfaméthoxazole sous la limite de détection du HPLC. Les solutions avec une concentration initiale de 60 mg/L ont requis une dose d’ozone de 331 mg/L et huit produits de dégradation ont été détectés. Les solutions ayant une concentration initiale de 100 μg/L ont requis une dose de 55 mg/L et seulement quatre produits de dégradation ont été détectés. L’analyse des produits de dégradation a démontré que le 4-aminobenzène sulfonamide, N-(3-phenylpropyl)-acetamide, 2-méthyl-benzoxaole et le phénol sont présents dans les solutions de faible et haute concentration initiale en sulfaméthoxazole. De plus, le méthanol, l’éthanol, l’acide acétique, l’acétate de méthyle et l’acétate d’éthyle sont ont été détectés dans les solutions de haute concentration.
41
Ghavipanjeh, Farideh. "Modelling and control of wastewater treatment". Thesis, Lancaster University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.250027.
Testo completo
42
Chalmers, E. "Biological phosphate removal from municipal wastewater". Thesis, University of Cambridge, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.597400.
Testo completoAbstract (sommario):
Phosphate removal from wastewater during treatment is a legal requirement to prevent environmental damage caused by releasing large amounts of nutrients into water courses. The most commonly applied removal methods, due to their ease of use, are based upon precipitation of the phosphate by chemical addition. An alternative method has been developed involving specialised micro-organisms, termed phosphate accumulating organisms (PAO), which take up and store greater than required amounts of phosphate. This process, designated enhanced biological phosphate removal (EBPR), has developed empirically since the observation that cycling the wastewater through anaerobic/aerobic phases selects for these PAO and the phosphate is removed from the liquid. There are still many aspects of the EBPR process that are far from fully understood; these include the identity of the organisms that are responsible for the phosphate uptake and the reasons why plants will occasionally stop removing phosphate. This project addresses these points, firstly by determining the effect of knockout and over-expression of ppk and ppx - genes known to be important in cellular polyphosphate metabolism in Pseudomonas putida, an organism found in sludge, which can accumulate polyphosphate. Previous mutational studies have mostly focused on Escherichia coli and Pseudomonas aeruginosa, which do not proliferate in sewage plants. The effect of the mutations upon growth, polyphosphate production and stress responses were ascertained. It appeared that two separate populations of polyphosphate were present, one being synthesized by polyphosphate kinase, the other by some as yet unidentified pathway. Further investigation of this 'large polyphosphate' established it was not polyphosphate but an unknown contaminating material that co-separated during the extraction procedure. Analysis of this compound suggested it was an exopolysaccharide, similar in character to alginate. The second aspect of the project focussed on the isolation of micro-organisms from a local EBPR plant followed by the selection, identification and characterization of potential PAOs. The development of a fully defined phosphate removing sludge community was attempted, in order to facilitate the study of the process. This was undertaken by operating a two litre bioreactor under EBPR conditions and allowing a self-selected community to develop from the inoculated isolates.
43
Ndonji, John Kayombo. "Removal of steroid oestrogens form wastewater". Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.531993.
Testo completo
44
O'Brien, Marie. "Predictive control of urban wastewater systems". Thesis, University of Strathclyde, 2006. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=21658.
Testo completoAbstract (sommario):
Within recent years, technological advances and stricter regulatory requirements have seen the increased use of automation and instrumentation within the wastewater treatment industry. As a result, advanced control strategies are required, to fully exploit the potential of these complex systems in addressing water quality concerns. Model based control strategies can be appropriate within the multivariable constrained wastewater system. In particular, the inherent model based nature of this approach can be valuable in the prediction of the treatment plant effluent quality required over a considered time period, to meet water quality standards. Multivariable linear predictive control is implemented for a benchmark treatment plant model, demonstrating the constraint handling ability of the predictive control structure. The limitations of an effluent-based control strategy in the maintenance of river quality is discussed. A more global approach to wastewater control must be considered in order to compensate against disturbances within the system. Tackling this concern, the incorporation of receiving water quality objectives within the control strategy is proposed. To this end, the application of linear MPC to the control of dissolved oxygen concentrations in the receiving waters under storm conditions is demonstrated. The drawbacks involved in a linear model based approach within a nonlinear urban wastewater system are considered. Several nonlinearities are present: the bioprocesses involved are by definition nonlinear, and are affected by varying wastewater load and characteristics. These can be the result of varying stormwater effects upon the treatment plant or emergency overflows to receiving waters. This therefore motivates the development of nonlinear strategies in the control of the wastewater processes. The control of SISO nonlinear processes within the urban wastewater system, such as dissolved oxygen, is demonstrated via the use of fuzzy gain-scheduled and Wiener model based predictive control. Additionally, the use of existing nonlinear process models in the control of wastewater processes is shown in the application of state dependent model predictive control.
45
Malik, Murtaza. "In-sewer treatment of domestic wastewater". Thesis, University of Newcastle Upon Tyne, 1996. http://hdl.handle.net/10443/363.
Testo completoAbstract (sommario):
Urban sewerage systems, which are normally used for the transport of wastewater from its origin to a wastewater treatment plant (WWTP), could be used as a treatment facility because (i) they contain heterotrophic bacteria capable of oxidising organic matter both suspended within the body of the flowing wastewater and attached to the surface of the wetted perimeter, and (ii) they provide retention times which are often comparable to those in a conventional activated sludge aeration tank and which, in some cases, may be equal to the hydraulic retention time in a WWTP. Using sewers as a treatment facility could be an economical method of alleviating the load on an existing WWTP or reducing the size of the proposed WWTP. The current study was undertaken to investigate the feasibility of using urban sewerage systems as suspended growth biological reactors for the treatment of domestic wastewater. The flow in a linear gravity sewer was simulated using a batch reactor fed with raw domestic wastewater. A comparison of simulated aerobic and anaerobic gravity transport indicated that aerobic treatment would be the most favoured method of in-sewer biological treatment. The soluble COD (SCOD) removal efficiencies over a retention period of 8 hours averaged 36 and 6% under aerobic and anaerobic conditions, respectively, at an average temperature of 22°C. The corresponding total COD removal averaged 8 and 11%, respectively. When the effluent samples, taken from the batch reactors after a retention period of 6 hours, were settled in a bench-scale settling column for one hour, the average suspended solids removal under aerobic conditions was 29% greater than those under anaerobic conditions. Under aerobic conditions, the removal of soluble organic matter during simulated gravity transport was found to be strongly influenced by the strength of the incoming wastewater. To investigate the effect of wastewater influent soluble COD (SCOD 0) and influent suspended solids (SS ()) on in-sewer aerobic treatment, 27 individual wastewaters collected from the inlets to three wastewater treatment plants were subjected to batch tests at 20°C. The SCOD over a retention period of 8 hours at 20°C averaged 48, 40 and 61% for wastewaters having low SCODo and low SS 0, high SCOD0 and low SS 0, and high SCOD0 and high SSo, respectively . The corresponding soluble BOD5 removal efficiencies averaged 64, 59, and 81%. A statistical analysis of soluble COD data revealed that, over a retention period of one to three hours, the soluble COD removal is only significantly influenced by SSo. At higher retention periods, the soluble COD removal was found to be significantly affected by both SCOD 0 and SSo. Soluble COD removal was found to follow first-order kinetics with respect to time. The oxygen uptake rate of the individual wastewaters varied widely and did not appear to show any clear relation with the SCOD0 or SSo. An increase in the suspended biomass of the wastewater by the addition of activated sludge, at a concentration as low as 100 mg VSS/1, at the inlet of the simulated aerobic gravity sewer resulted in a significant increase in the removal of soluble organic matter. The soluble COD removal in the seeded wastewater was found to increase almost linearly with the increase in seed concentration in the range of 100-1000 mg/l. The effect of seed concentration on soluble COD removal however, appeared to diminish with the increase in retention time. SCOD removal in the seeded wastewater appeared to follow secondorder kinetics with respect to time. At an initial seed concentration of 100-1000 mg/1, the batch reactor's effluent after a retention period of 6 hours showed satisfactory settling characteristics. The oxygen uptake rate of the seeded wastewater did not show any specific trend over time at seed concentrations of 100 and 250 mg/1, while at higher seed concentrations it was similar to that observed in a typical plug flow activated sludge aeration tank. The results of the case study in which the wastewater collected from the inlet of the Greater Amman Siphon (GAS) was maintained aerobic in a batch reactor, showed that by maintaining aerobic conditions in the GAS, average SCUD and soluble BOD 5 removal efficiencies of 60 and 78%, respectively, could be achieved over 8 hours at an average temperature of 25°C. The average oxygen demand of the wastewater was estimated to be 30 mg/l.h. The result of the current study suggest a strong possibility of using urban sewerage systems as an aerobic biological reactor for the removal of soluble organic matter during transit.
46
Zeng, Qingfu. "Photocatalystic oxidative decoloration of textile wastewater". Thesis, University of Leeds, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.410974.
Testo completo
47
Tree, Julia Anne. "The virucidal efficacy of wastewater disinfection". Thesis, University of Surrey, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.387537.
Testo completo
48
Murcott, Susan. "Performance and innovation in wastewater treatment". Thesis, Massachusetts Institute of Technology, 1992. http://hdl.handle.net/1721.1/13122.
Testo completo
49
Bhattacharya, Mahua M. Eng Massachusetts Institute of Technology. "Wastewater sludge management options for Honduras". Thesis, Massachusetts Institute of Technology, 2009. http://hdl.handle.net/1721.1/50618.
Testo completoAbstract (sommario):
Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2009.Includes bibliographical references (leaves 48-50).
Sludge management is a fundamental area of concern across wastewater treatment systems in Honduras. The lack of timely sludge removal has led to declining plant performance in many facilities throughout the country. In addition to maintaining treatment efficiency, proper sludge management is important for mitigating pathogen levels and providing opportunities for safe beneficial reuse of biosolids. Based on analyses of data collected at waste stabilization ponds in the municipalities of Puerto Cortes and La Lima, sludge was characterized with respect to quantities generated (accumulation rates) and quality (helminths and heavy metals content). A review was conducted of appropriate sludge treatment technologies including sludge drying beds, alkaline stabilization, acid stabilization, anaerobic digestion, and composting. These options were evaluated based on a set of selected criteria. Anaerobic digestion, alkaline stabilization, and composting were all found to be suitable methods of sludge treatment. Alkaline stabilization and composting are well suited to facilities with sufficient land. Anaerobic digestion was recommended for areas with land constraints. Treated biosolids can be beneficially used within the community and/or at a regional scale. Potential regional end-uses include soil amendment in agriculture and forestry, or for land reclamation of mined lands. Public participation and acceptance is essential for the success of a biosolids reuse program. Potential strategies for engaging the community and addressing public concerns regarding biosolids were identified.
by Mahua Bhattacharya.
M.Eng.
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Halageri, Natasha. "Odor Monitoring at Wastewater Treatment Plants". ScholarWorks@UNO, 2012. http://scholarworks.uno.edu/td/1580.
Testo completoAbstract (sommario):
Hydrogen sulfide (H2S) is notable for its toxicity and corrosion is one of the major sources of odor in wastewater treatment plants. Evaluation of existing or potential odor problems requires knowledge of the type of compounds likely to cause such problems and the mechanism of their formation in wastewater systems which is discussed in this paper. For the present study, the East Bank wastewater treatment plant was chosen since it is the largest wastewater treatment facility within Jefferson Parish, Louisiana. To combat the odor problems in this facility, a monitoring program was designed and developed to characterize the severity of the problem. The program involved continuous ambient monitoring followed by careful evaluation of the data obtained from sample collection and analysis. Different instruments were strategically placed within the facility after a hot-spot analysis to determine the major sources of odor generation.