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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

The application of a membrane bioreactor for wastewater treatment on a northern Manitoban Aboriginal community

Frederickson, Kristinn Cameron 06 January 2006 (has links)
Water infrastructure on Aboriginal communities in Canada, and specifically Northern Manitoba is in sub-standard condition. A recent Government of Canada study indicated that an estimated $1.5 billion would need to be spent to improve this infrastructure. September 2003 through July 2004, an examination of the effectiveness of a membrane bioreactor (MBR) in a Northern Manitoban Aboriginal community took place. This study was intended to identify and test an appropriate and effective solution for the lack of adequate wastewater treatment in these communities. The MBR system, employing a Zenon ZW-10 ultrafiltration membrane, was designed and constructed at the University of Manitoba. It was installed and tested in two phases at the Opaskwayak Cree Nation Reserve in Northern Manitoba. Phase I was a direct comparison between the pilot-scale MBR and the community’s existing Sequencing Batch Reactor (SBR) with sand filter. This phase occurred from September 2003 until December 2003. The MBR, with an SRT of 20-days and an HRT of 10 hours, outperformed the SBR in every category despite 2 mechanical/electrical failures that resulted in the loss of biomass from the MBR. The SBR/Sand filter combination had BOD, TSS, and TKN concentrations of 30.3 mg/L, 27.5 mg/L, and 8.4 mg/L, respectively. By comparison, the BOD, TSS, and TKN concentrations in the MBR effluent were <6 mg/L, <5 mg/L, and 1.3 mg/L respectively. Phase II, from March 2004 through July 2004, tested the overall MBR efficacy and intended to assess a novel remote control and monitoring system. The MBR SRT was adjusted to 40-days and, as expected, the MBR MLVSS concentration increased to a relatively stable 5000 mg/L. The MBR continued to provide high quality effluent with some exceptions. Despite the 0.034 μm pore size, the total coliforms and TSS measured in the effluent were higher than in Phase I. This indicates a compromised membrane, faulty sampling procedures, or biological regrowth downstream of the membrane. This failure could point to the need for some form of tertiary disinfection. Also in Phase II, a remote control and monitoring program was implemented. The controlling PC was controlled via the internet using pcAnywhere software. The software allowed for real-time monitoring and complete control of the pilot system. In conclusion, the pilot-scale MBR yielded consistent, high quality wastewater effluent and this would benefit the pristine environments existing in Manitoba’s north. The potential hands-free operation could be utilized to provide support to communities lacking sufficient wastewater treatment know-how.
12

The application of a membrane bioreactor for wastewater treatment on a northern Manitoban Aboriginal community

Frederickson, Kristinn Cameron 06 January 2006 (has links)
Water infrastructure on Aboriginal communities in Canada, and specifically Northern Manitoba is in sub-standard condition. A recent Government of Canada study indicated that an estimated $1.5 billion would need to be spent to improve this infrastructure. September 2003 through July 2004, an examination of the effectiveness of a membrane bioreactor (MBR) in a Northern Manitoban Aboriginal community took place. This study was intended to identify and test an appropriate and effective solution for the lack of adequate wastewater treatment in these communities. The MBR system, employing a Zenon ZW-10 ultrafiltration membrane, was designed and constructed at the University of Manitoba. It was installed and tested in two phases at the Opaskwayak Cree Nation Reserve in Northern Manitoba. Phase I was a direct comparison between the pilot-scale MBR and the community’s existing Sequencing Batch Reactor (SBR) with sand filter. This phase occurred from September 2003 until December 2003. The MBR, with an SRT of 20-days and an HRT of 10 hours, outperformed the SBR in every category despite 2 mechanical/electrical failures that resulted in the loss of biomass from the MBR. The SBR/Sand filter combination had BOD, TSS, and TKN concentrations of 30.3 mg/L, 27.5 mg/L, and 8.4 mg/L, respectively. By comparison, the BOD, TSS, and TKN concentrations in the MBR effluent were <6 mg/L, <5 mg/L, and 1.3 mg/L respectively. Phase II, from March 2004 through July 2004, tested the overall MBR efficacy and intended to assess a novel remote control and monitoring system. The MBR SRT was adjusted to 40-days and, as expected, the MBR MLVSS concentration increased to a relatively stable 5000 mg/L. The MBR continued to provide high quality effluent with some exceptions. Despite the 0.034 μm pore size, the total coliforms and TSS measured in the effluent were higher than in Phase I. This indicates a compromised membrane, faulty sampling procedures, or biological regrowth downstream of the membrane. This failure could point to the need for some form of tertiary disinfection. Also in Phase II, a remote control and monitoring program was implemented. The controlling PC was controlled via the internet using pcAnywhere software. The software allowed for real-time monitoring and complete control of the pilot system. In conclusion, the pilot-scale MBR yielded consistent, high quality wastewater effluent and this would benefit the pristine environments existing in Manitoba’s north. The potential hands-free operation could be utilized to provide support to communities lacking sufficient wastewater treatment know-how.
13

Degradação anaeróbia de formaldeído em reator operado em bateladas seqüênciais contendo biomassa imobilizada / Anaerobic degradation of formaldehyde in sequencing batch reactor containing immobilized biomass

Noemi da Silveira Pereira 27 July 2007 (has links)
Resíduos de formaldeído são descarregados de diversas formas no ambiente, resultantes de muitos processos industriais, e de seu uso como conservantes. A pesquisa por tecnologias adequadas para o tratamento de formaldeído aponta processos físico-químicos e biológicos, com atenção especial para os processos anaeróbios por constituírem sistemas compactos e de baixo consumo energético. No entanto, algumas lacunas presentes na pesquisa sobre tratamento anaeróbio de formaldeído e alguns pontos de discordância devem ser esclarecidos. Em muitos casos, esses resíduos são descartados de forma intermitente, motivando a opção por processos em batelada. Nesse contexto, o presente estudo avaliou a degradação de formaldeído em reator anaeróbio operado em bateladas seqüenciais, contendo biomassa imobilizada em espuma de poliuretano. O desempenho do reator foi monitorado para várias concentrações afluentes de formaldeído, variando de 31,6 a 1104,4 mg/L. Os resultados obtidos indicaram excelente estabilidade do reator e eficiência de remoção de formaldeído acima de 99%. Entretanto foi constatado acúmulo de matéria orgânica no efluente devido à presença de ácidos orgânicos, principalmente acético e propiônico. Essa constatação levanta um questionamento importante sobre a rota anaeróbia de degradação do formaldeído, que pode diferir substancialmente do que foi registrado na literatura. Os ácidos gerados não foram degradados pela biomassa exposta ao formaldeído, contudo poderiam ser facilmente removidos com a utilização de um reator em série com inoculo adaptado à remoção de ácidos orgânicos. / Formaldehyde residues are discharged into the environment in several different ways, as a result of several industrial processes, as well as its use as a preservative. Research for suitable technologies for treatment of formaldehyde points to physical-chemical and biological processes, with special attention to anaerobic processes, once they represent compact systems with low energy requirements. Nevertheless, some blank spaces still remaining in the research regarding anaerobic treatment of formaldehyde must be filled, and some points of disagreement must be clarified. In several cases, formaldehyde residues are discharged intermittently, favoring the choice of batch processes. In this context, the present study evaluated the degradation of formaldehyde in an anaerobic sequencing batch reactor, containing biomass immobilized in polyurethane foam matrices. Reactor performance was monitored for different influent formaldehyde concentrations, ranging from 31.6 to 1104.4 mg/L. Results obtained indicate excellent reactor stability and efficiency in formaldehyde removal above 99%. However, accumulation of organic matter was observed in the effluent, due to presence of non-degraded organic acids, especially acetic and propionic. This observation poses an important question regarding the anaerobic route of formaldehyde degradation, which might differ substantially from that reported in literature. The degradation of the generated products could occur in another reactor in serie containing biomass adapted to organic acids removal.
14

Determining the efficiency of the anammox process for the treatment of high- ammonia influent wastewater

Gokal, Jashan 08 1900 (has links)
Submitted in fulfillment of the degree of Master of Applied Science: Biotechnology, Durban University of Technology, Durban, South Africa, 2017. / Domestic wastewater contains a high nutrient load, primarily in the form of Carbon (C), Nitrogen (N), and Phosphorous (P) compounds. If left untreated, these nutrients can cause eutrophication in receiving environments. Biological wastewater treatment utilizes a suspension of microorganisms that metabolize this excess nutrient load. Nitrogen removal in these systems are due to the synergistic processes of nitrification and denitrification, each of which requires its own set of operating parameters and controlling microbial groups. An alternative N-removal pathway termed the anammox process allows for total N-removal in a single step under anoxic conditions. This process, mediated by the anammox bacterial group, requires no organic carbon, produces negligible greenhouse gases and requires almost 50 % less energy than the conventional process, making it a promising new technology for efficient and cost-effective N-removal. In this study, a sequencing batch reactor (SBR) was established for the autotrophic removal of N-rich wastewater through an anammox-centric bacterial consortia. The key microbial members of this consortia were characterized and quantified over time using molecular methods and next generation sequencing to determine if the operational conditions had any effect on the seed inoculum population composition. Additionally, local South African wastewater treatment plants were screened for the presence of anammox bacteria through 16S rRNA amplification and enrichment in different reactor types. A 3 L bench scale SBR was inoculated with active biomass (~ 5 % (v/v)) sourced from a parent anammox enrichment reactor, and maintained at a temperature of 35 °C ± 1 °C. The reactor was fed with a synthetic wastewater medium containing no organic C, minimal dissolved oxygen (< 0.5 mg/L), and N in the form of ammonium and nitrite in the ratio of 1:1.3. The reactor was operated for a period of 366 days and the effluent ammonium, nitrite and nitrate were measured during this period. The hydraulic retention time was controlled at 4.55 days from Day 1 to Day 250, and thereafter shortened to 1.52 days from Day 251 to Day 360 due to an increased nitrogen removal rate (NRR). During Phase I of operation (Day 1 to Day 150), the reactor performance gradually increased up to an NRR of ~160 mg N/day. During Phase II (Day 151 to Day 250), the overall reactor performance decreased with the NRR decreasing to ~90 mg N/day, while Phase III (Day 251 to Day 366) displayed a gradual recovery of NRR back to the reactor optimum of ~160 mg N/day. The accumulation of nitrate in the effluent during the latter parts of Phase II and Phase III, coupled with oxygen ingress (~2.1 mg/L) in the same period, indicated that it was not the anammox pathway that was dominating N-removal within the reactor, but more likely the second half of the nitrification pathway mediated by the nitrite oxidizing bacteria (NOB). This was further confirmed through molecular analysis, which indicated that the bacterial population had shifted significantly over the course of reactor operation. Quantitative PCR methods displayed a decrease in all the key N-removing population groups from Day 1 to Day 140, and a marginal increase in anammox and aerobic ammonia oxidizing bacteria from Day 140 – Day 260. From Day 300 onwards, NOB had started dominating the system, simultaneously suppressing the growth of other N-removing bacterial groups. Despite this, the NRR peaked during this period, indicating an alternative mechanism for ammonia removal within the reactor system. A total population analysis using NGS was also performed, which corroborated the QPCR results and displayed a population shift away from anammox bacteria towards predominantly NOB and members of the phylum Chloroflexi. The proliferation of aerobic NOB and Chloroflexi, and the suppression of anammox bacteria, indicated that DO ingress was indeed the primary cause of the population shift within the reactor. Despite this population shift, N-removal within the reactor remained high. New pathways have recently emerged which implicate these two groups as potential N oxidizers, with specific NOB groups showing the ability for oxidation of ammonia through the comammox process, and members of the Phylum Chloroflexi being capable of nitrite reduction. This could imply that an alternate pathway was responsible for the majority of N-removal within the system, in addition to the anammox and conventional nitrification pathways. Additionally, in an attempt to detect a local anammox reservoir, eleven wastewater systems from around South Africa were screened for the presence of anammox bacteria. Through direct and nested PCR-based screening, anammox bacteria was not detectable in any of the activated sludge samples tested. Based on the operating conditions of the source wastewater systems, a subset of three sludge samples were selected for further enrichment. After 60-110 days of enrichment in multiple reactor configurations, only one reactor sample tested positive for the presence of anammox bacteria. Although this result indicates that anammox bacteria might not be ubiquitous within every biological wastewater system, it is more likely that anammox bacteria might only be present at undetectable levels, and that an extended enrichment prior to screening is necessary for a true representation of anammox bacterial prevalence in an environmental sample. / M
15

Pilot-scale anaerobic digestion of municipal biowaste with thermal hydrolysis pre-treatment / 水熱前処理を用いた有機性廃棄物のパイロット-スケール嫌気性消化に関する研究

Zhou, Yingjun 25 March 2013 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17542号 / 工博第3701号 / 新制||工||1563(附属図書館) / 30308 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 高岡 昌輝, 教授 田中 宏明, 教授 米田 稔 / 学位規則第4条第1項該当
16

Biological phosphorus removal from edible oil effluent by anaerobic- aerobic sequencing batch reactor

Manganyi, Abel Jwili January 2004 (has links)
Dissertation submitted in compliance with the requirements of the Master' s Degree in Technology: Biotechnology at the Durban Institute of Technology, 2004. / The objective of this study was to evaluate the characteristics and treatability of process wastewater from an edible oil refining industry, which discharge its effluent into a sewer system. The main objective was to assess a laboratory scale treatment process that would produce effluent having a regulatory acceptable phosphate concentration (below 20 mgIL) prior to discharge into municipal sewer system. A single stage laboratory-scale anaerobic-aerobic sequencing batch reactor (BPR-SBR) with a total volume adjustable up to 10L was designed for biological phosphorus removal. The BPR-SBR was run at 10 days sludge age, 8 hours hydraulic retention time and organic load of ~ 0.38 kg COD/kg MLSS.d for 158 days to evaluate its performance for bio-P removal efficiency. The BPR-SBR system showed a consistent P removal efficiency of up to 78.40 %, 80.15 % COD and 72.43 % FOG reduction. The laboratory scale study has demonstrated that the SBR technology is suitable for treating wastewater from edible oil producing industry. / M
17

Compréhension et optimisation d'un procédé de biodégradation d'effluents agricoles composés de pesticides en mélange / Optimization of a biodegradation process for agricultural effluents composed of mixed pesticides

Thevenin, Nicolas 11 July 2016 (has links)
Ces travaux ont consisté à développer un procédé de traitement biologique des eaux contaminées en produits phytosanitaires (PF) issues du lavage des matériels de pulvérisation de PF. Ce procédé s’appuie surl’inoculation d’une culture bactérienne mixte sélectionnée et d’un matériau sorbant constitué de rafles de maïs broyées.Tout d’abord, un mélange modèle de PF,constitué de 6 herbicides, 3 fongicides et 1 insecticide, a été créé. Après avoir mis au point la production de l’inoculum en présence de ce mélange et étudié les propriétés sorbantes des rafles de maïs, les paramètres de traitement ont été définis à petite échelle de laboratoire et validés en réacteur.Finalement, le procédé développé est un traitement en réacteur batch séquentiel de 28 jours qui permet de réduire de plus de 50 % la masse initiale des PF du mélange modèle. Malgré la réduction des teneurs en PF, la phytotoxicité due aux résidus d’herbicides des effluents traités est encore trop élévée et ne permet pas de valider l’épandage sur un lit planté de roseaux comme post-traitement de la fraction liquide. / Aim of this work was to treat effluentsobtained from rinsing pesticide (PF) spraying equipments by developing biological treatment process into bioreactor with selected mixed bacterial culture and adsorption support consisting of crushed corn cobs. First, a model PF mixture was designed to represent agriculturaleffluents at watershed scale. This mixture was composed by 6 herbicides, 3 fungicides and 1 insecticide. Then, inoculum production under PF pressure was developed and sorption properties of corn cobswere investigated. Process parameters were defined at small-scale laboratory and validated into bioreactors. Thus, developed processwas a28 days sequential batch reactortreatment, which reduced more than 50% of molecules weight of model mixture.Despite of this process significantely reduced treated effluents PF contents, remaining phytotoxicity due to herbicide residues failed validation of their post-treatment on a bed planted with reeds.
18

Evaluation of an Industrial Byproduct Glycol Mixture as a Carbon Source for Denitrification

Liang, Wei 24 June 2013 (has links)
In order to meet increasingly stringent total nitrogen limits, supplemental carbon must be added to improve the performance of the biological nutrient removal process. An industrial by-product that contained ethylene glycol and propylene glycol was used as a substitute carbon source for methanol in this study. The objectives of this study were to investigate the efficiency of using the glycol mixture as carbon source, including the calculation of denitrification rate and yield at two different initial concentrations of glycols. Possible inhibition effect on nitrification was also investigated. Three SBR reactors were operated by adding methanol, a low dosage of glycol, and a high dosage of glycol into the reactors. The low dosage glycol reactor exhibited the best performance, with the highest denitrification rate of 11.55 mg NOx-N/g MLVSS"h and the lowest yield of 0.21 mg VSS/mg COD. Small nitrite accumulation was observed in the low dosage glycol reactor (COD=185"•15 mg/L), but effluent quality was not influenced. Excess glycol in the reactor caused deteriorated performance. The high dosage glycol reactor (COD=345"•20 mg/L) performed with the lowest denitrfication rate of 8.56 mg NOx-N/g MLVSS"h and the highest yield of 0.55 mg VSS/ mg COD. The reactor with the high dosage of glycol also inhibited the lowest nitrification rate of 1.15 mg NH3-N oxidized/g MLVSS"h, which indicated that excess glycol may cause nitrification inhibition. / Master of Science
19

A STUDY OF AEROBIC METHANOL ADDITION IN DENITRIFYING SEQUENCING BATCH REACTORS

PARSONS, MICHAEL E. 04 April 2007 (has links)
No description available.
20

Effect of Reactor Feeding Pattern on Performance of an Activated Sludge SBR

Cubas Suazo, Francisco Jose 06 December 2006 (has links)
The possible effects of changes in the feeding pattern on activated sludge properties related to bioflocculation have been analyzed in lab scale sequencing batch reactors (SBR) in order to determine if these changes in effluent water quality and settling and dewatering properties are significant, so they can be considered in future studies or if they can be recommended as crucial when operating and designing wastewater treatment plants. The activated sludge process is widely used to treat wastewater from both industrial and municipal sources. Biomass from industrial facilities containing high monovalent to divalent ion content usually settles poorly, which leads to low quality effluents that fail to meet environmental requirements. Therefore, the combined effect of feeding pattern plus the addition of sodium to activated sludge reactors was studied in this experiment. A series of SBRs were operated at different sodium concentrations that ranged from 1.5 - 15 meq/L and different feeding times that ranged from 1 minute to 4 hours. Biomass samples were taken from each reactor to study the settling and dewatering properties and effluent samples were used to analyze the amount of organic matter and exocellular polymeric substances present due to deflocculation. As expected, the changes in feeding strategies affected all of the properties measured. When the feeding time was maintained low (pulse feed) the effluent quality and settling properties were the best. As the feeding time was increased the effluent quality, settling, and dewatering properties increased suggesting that the way in which the reactors were fed affected the overall bioflocculation process. The causes of the high deflocculation observed are not well understood, but data suggest that a microbial community change could have affected exocellular biopolymers which are believed to play an important role on bioflocculation. This research demonstrates the importance of the interaction between cation content and feeding pattern when operating a wastewater treatment plants and when reporting lab-scaled results related to settling and bioflocculation. / Master of Science

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