Toxic shock events can be detrimental to wastewater treatment systems and can result in long-term losses of system performance. If warned of an impending toxic shock, operators would have the opportunity to implement process controls that could help mitigate the effects of the shock event. The objective of this project was to evaluate the effectiveness of a developed corrective action strategy (involving aerobic endogenous respiration) on an enhanced biological phosphorus removal (EBPR) wastewater treatment plant (WWTP) shocked with chlorine. Three identical, laboratory-scale systems were designed to mimic one train of the Long Creek Water Resources Reclamation Facility (WRRF, Gastonia, NC). The basis of this study is a comparative performance analysis among the three trains; a negative control (unshocked and operated normally), a positive control (shocked with hypochlorite and operated normally), and the corrective action (shocked with hypochlorite and process controls implemented). Comparative performance analysis among the three trains was based on effluent quality, performance stability, and biomass kinetics as indicated by rates of respiration and phosphate release and uptake. The shock event and corrective action strategy both inhibited EBPR. After an initial perturbation, the positive control matched the performance of the negative control. The corrective action, however, exhibited significant instability in EBPR performance. Regardless of whether aerobic or anaerobic sludge storage conditions are selected, endogenous respiration will still result in system instability. It is recommended, therefore, that measures be taken to avoid imposing endogenous conditions on isolated sludge during a short-term toxic shock event. / Master of Science

The goal of this research was to characterize the effects of temperature changes on the denitrification process in a biological nutrient removal (BNR) system. Specifically, there were three objectives. First, the effects of temperature changes on denitrification rates by a bacterial population from a BNR system were investigated. Next, the role which PHAs (poly-beta-hydroxyalkanoates) played in the denitrification process were examined. Finally, the effect of temperature changes on the production and consumption rates of PHAs was determined. Sacrificial batch experiments were performed to assess the kinetic and chemical trends present in the denitrification process. Mixed liquor from the last anaerobic zone of a pilot scale BNR system was injected into vials. These vials were pre-purged with nitrogen gas in order to prevent dimolecular oxygen (02) from being entrained in the mixed liquor. Next, the vials were placed on a shaker table for 30 minutes in order to allow all external COD to be consumed. Following this, each vial was injected with nitrates and various macronutrients. This process was repeated for three different sets of batch tests; each set was identical except for the added substrate. One set received no added substrate while the other two received either acetate or glucose. Vials were sacrificed over a period of three hours and analyzed for nitrate, phosphate, PHB (polybeta-hydroxybutyrate), PHV (poly-beta-hydroxyvalerate), glucose and acetate. / Master of Science

Grundämnet fosfor är essentiellt för alla levande organismer men kan i överskott leda till problem med övergödning. Det finns därför höga krav på halten avloppsreningsverk släpper ut till recipienter. Idag sker stora delar av fosforreningen kemiskt genom dosering av fällningskemikalier. Det finns dock fördelar med att istället använda en biologisk metod som bygger på att reningsförhållandena premierar tillväxt av bakterier med möjlighet att ta upp mer fosfor än de behöver för sin cellväxt.  Bakterierna gynnas genom omväxlande anaeroba och aeroba zoner samt en god tillgång på lättillgänglig kolkälla och fosfor. Många reningsverk kombinerar den kemiska och biologiska fosforreningen men de är inte alltid kompatibla och den kemiska kan störa ut den biologiska. På Kungsängsverket finns sedan 2010 förutsättningar för en biologisk fosforreduktion men processen har inte fungerat tillfredsställande. Anledningen tros vara höga halter järn i slammet. Järnet fäller delar av den fosfor som är nödvändig för processen. Arbetet har därför syftat till att undersöka om det går att tvätta bioslammet på järn och på så sätt nå en fungerande fosforrening; vid vilka järnhalter detta sker och vilka besparingar det skulle kunna leda till för Uppsala Vatten och Avfall AB. För vidare utredning genomfördes ett pilotförsök där två reaktorer byggdes, en referensreaktor och en försöksreaktor. Reaktorerna matades sedan med vatten med olika sammansättning, främst gällande järnhalt. Även befintlig data för verket och uppgifter kring förutsättningarna på andra reningsverk med en fungerande biologisk fosforreduktion undersöktes. Pilotförsöket visade att det går att tvätta bioslammet på järn då en sjunkande halt sågs under försökets gång. Halten sjönk från 40 mg Fe/g TS till 18 mg Fe/g TS i försöksreaktorn. En fungerande fosforrening uppnåddes aldrig så inga slutsatser gällande besparingar, eller vid vilka järnhalter en fungerande rening sker, kan dras. Andra reningsverk med biologisk fosforrening har kring 10 mg Fe/g TS vilket ger en indikation på vad halten bör vara. Pilotförsöket visade också att dosering av polymer ledde till att stora delar av den inkommande kolkällan fälldes, kolkälla som behövs för fungerande fosfor- och kväverening. Recirkulation av nitratkväve sågs hämma det fosforsläpp som vid fungerande rening ska ske i den anaeroba zonen och tros ha stört reningen under försökets gång. Förutsättningarna för biologisk fosforrening på Kungsängsvrket anses inte vara optimala gällande avloppsvattnets sammansättning, recirkulering av nitratkväve till den anaeroba zonen och mängden lättillgänglig kolkälla från hydrolysbassängen. / Phosphorus is an essential element but can cause eutrophication when present in high concentrations. Emission requirements from municipal wastewater treatment plants are therefore strict. Today chemical precipitation is common but there are advantages to using a biological method. It is based on creating conditions that favor growth of a special type of bacteria. These bacteria absorb more phosphorus than they need for growth. To do this they need alternating anaerobic and aerobic zones and access to carbon and phosphorus. A combination between the two methods are common but the precipitation chemicals can under some conditions disturb the biological removal.   At Kungsängsverket the process of biological phosphorus removal has been in place since 2010. It has not worked adequately and the reason could be high concentrations of iron in the biological sludge. The purpose of this thesis has therefore been to investigate whether it is possible to wash out the iron from the bio-sludge and as a result reach a satisfying reduction of phosphorus, to see at which iron content this might happen and what kind of savings a functioning biological phosphorus removal might lead to for Uppsala Vatten och Avfall AB.  To test the hypothesis two reactors were built, a reference reactor and an experimental reactor. The two were fed with water with different compositions, primarily regarding iron content. Also, existing data was examined from the plant and records regarding sludge composition at plants with working biological phosphorus removal. The pilot test showed that it was possible to wash out the iron from the biological sludge. Iron content in the experimental reactor went down from 40 mg Fe/g DM to 18 mg Fe/g DM. A satisfying reduction of phosphorus was never achieved and no conclusions can be drawn regarding savings or at which iron content a reduction might happen. Other wastewater treatment plants with biological phosphorus reduction have shown to have a content of about 10 mg Fe/g DM which can be used as an indication. According to the pilot test dosing of polymer can lead to a large precipitation of carbon source. Lack of carbon will inhibit phosphorus and nitrogen removal. Circulation of nitrate repressed the release of phosphate in the anaerobic zone and is believed to have disturbed the removal during the pilot. The conditions for biological phosphorus removal at Kungsängsverket are not ideal as to the composition of the wastewater, the circulation of nitrate to the anaerobic zone and the amount of carbon source from the hydrolysis.

Constructed wetlands are considered an inefficient technology for long-term phosphorus (P) removal. The P retention effectiveness of subsurface wetlands can be improved by using appropriate substrates. The objectives of this study were to: (i) use sorption isotherms to estimate the P sorption capacity of the two materials, masonry sand and light weight expanded shale; (ii) describe dissolved P removal in small (2.7 m3) subsurface flow wetlands; (iii) quantify the forms of P retained by the substrates in the pilot cells; and (iv) use resulting data to assess the technical and economic feasibility of the most promising system to remove P. The P sorption capacity of masonry sand and expanded shale, as determined with Langmuir isotherms, was 60 mg/kg and 971 mg/kg respectively. In the pilot cells receiving secondarily treated wastewater, cells containing expanded shale retained a greater proportion of the incoming P (50.8 percent) than cells containing masonry sand (14.5 percent). After a year of operation, samples were analyzed for total P (TP) and total inorganic P (TIP). Subsamples were fractionated into labile-P, Fe+Al-bound P, humic-P, Ca+Mg-bound P, and residual-P. Means and standard deviations of TP retained by the expanded shale and masonry sand were 349 + 169 and 11.9 + 18.6 mg/kg respectively. The largest forms of P retained by the expanded shale pilot cells were Fe+Al- bound P (108 mg/kg), followed by labile-P (46.7 mg/kg) and humic-P (39.8). Increases in the P forms of masonry sand were greatest in labile-P (7.5 mg/kg). The cost of an expanded shale wetland is within the range of costs conventional technologies for P removal. Accurate cost comparisons are dependent upon expansion capacity of the system under consideration. Materials with a high P sorption capacity also have potential for enhancing P removal in other constructed wetland applications such as stormwater wetlands and wetlands for treating agricultural runoff.

Coagulation is a ubiquitous process in the treatment of raw surface water for eventual potable use. Despite its capabilities, the sheer scale of its use is manifested in the volumes of chemicals it demands and waste sludge it produces. Recovering and reusing the chemical activity of the coagulant sludge in water treatment is a logical solution but this practice has been restricted by the presence of contaminants within the sludge. This thesis has investigated methods that can separate the coagulant metals from these primarily natural organic contaminants, with an aim of producing a sufficiently pure coagulant for effective treatment performance when reused. A process of ultrafiltration of the impure regenerated coagulant followed by a powdered activated carbon polishing stage compared favourably to a number of other separation processes and was found to remove the most dissolved organic compounds. When the purified coagulant was used to treat raw water, it provided better turbidity removal than commercial coagulant and matched its removal of trihalomethane precursors, making the process suitable for consideration at full-scale. Analysis of the whole life cost suggested that such performance could be reproduced at full-scale within a 25 year payback period. The reuse of even purified recovered coagulants in drinking water treatment still carries risks which may deter its implementation. Therefore the efficacy of recovered coagulants in the role of phosphorus removal from wastewater was also investigated. This showed that both acidified and unacidified waterworks sludges, with sufficient contact time, could remove similar levels of phosphorus as fresh coagulants, at approximately half the whole life cost.

Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-02-26T12:41:19Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Elivânia Vasconcelos Moraes dos Santos.pdf: 12370912 bytes, checksum: 6d2546d30ef4aaab7cbd742d981ddf1f (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-03-09T14:13:43Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Elivânia Vasconcelos Moraes dos Santos.pdf: 12370912 bytes, checksum: 6d2546d30ef4aaab7cbd742d981ddf1f (MD5) / Made available in DSpace on 2016-03-09T14:13:43Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Elivânia Vasconcelos Moraes dos Santos.pdf: 12370912 bytes, checksum: 6d2546d30ef4aaab7cbd742d981ddf1f (MD5) Previous issue date: 2014-12-15 / In recent years there has been an intensified studies on the biological removal of phosphorus from wastewater and as a result, a breakthrough in the understanding of the microbial groups involved in this process. This was possible due to the availability of different laboratory techniques for the identification and quantification of these organisms that often is associated with molecular biology. As part of sanitary engineering, new approaches can be inserted to enable the determination of operating parameters that support rational projects, such respirometry combined with mathematical modeling of microbial metabolisms. Furthermore, the possibility of identifying the predominance of phosphorus accumulating organisms (PAO) by means of techniques available and low cost is attractive in countries such as Brazil. For this reason, nine activated sludge systems were operated with different strategies to stimulate not only the predominance of PAO, in four of these systems as well as in other settings, the prevalence of other bacterial groups as glycogen storage batteries (GAO), heterotrophic ordinary (OHO) and mixed populations. Five tools based on physico-chemical and respirometric tests were used to assess the prevalence of different populations from stoichiometric ratios and kinetic data. The PAO predominance strategy that got the most attention in average temperature of 25°C, which consisted of a system that promoted denitrification via nitrite using exclusively propionate as organic carbon source. From the data obtained was built an array of predominance of PAO, also using mixed sludge, OHO and GAO comparatively. The results obtained in this study can be applied in rational models and optimized projects and support other biotechnological applications. / Nos últimos anos, tem havido uma intensificação de estudos sobre a remoção biológica de fósforo de águas residuárias e, como consequência, um avanço no conhecimento dos grupos microbianos envolvidos neste processo. Isso foi possível devido à disponibilidade de diferentes técnicas laboratoriais para a identificação e quantificação desses organismos que frequentemente encontra-se associada à biologia molecular. No âmbito da engenharia sanitária, novas abordagens podem ser inseridas para viabilizar a determinação de parâmetros operacionais que subsidiem projetos racionais, a exemplo da respirometria aliada à modelagem matemática de metabolismos microbianos. Além disso, a possibilidade de identificar a predominância de organismos acumuladores de fósforo (PAO) por meio de técnicas acessíveis e de baixo custo é atrativa para países como o Brasil. Por esse motivo, nove sistemas de lodo ativado foram operados com diferentes estratégias para estimular não só o predomínio de PAO, em quatro destes sistemas, bem como, nas demais configurações, a predominância de outros grupos bacterianos como acumuladores de glicogênio (GAO), heterotróficos ordinários (OHO) e populações mistas. Foram utilizadas cinco ferramentas com base em análises físico-químicas e testes respirométricos, para avaliar a predominância de populações diferentes a partir de relações estequiométricas e dados cinéticos. A estratégia de predominância de PAO que obteve maior destaque, em temperatura média de 25°C, foi a que consistia em um sistema que promovia desnitrificação via nitrito utilizando exclusivamente propionato como fonte de carbono orgânico. A partir dos dados obtidos foi construída uma matriz de predominância de PAO, utilizando também lodos mistos, OHO e GAO de forma comparativa. Os resultados obtidos neste trabalho poderão ser aplicados em modelos racionais e projetos otimizados e fundamentar outras aplicações biotecnológicas.

<p>Hammarby Sjöstad is a new district of southern Stockholm built with focus on reduced environmental impact by recirculation of materials and sustainability. The environmental goals aim to cut the water consumption by half and a separate storm water treatment. Thus, the wastewater will be more concentrated and will originate from the households only. The Sjöstad project includes the idea of a local treatment plant for the household wastewater. To evaluate this possibility, Sjöstadsverket, an experimental treatment plant was constructed. New wastewater treatment processes are tested and evaluated and compared to conventional methods including both aerobic and anaerobic treatment processes.</p><p>One of the aerobic treatment processes includes enhanced biological phosphorus removal (EBPR or Bio-P) as the method for the removal of phosphorus. In biological phosphorus removal the wastewater is alternately being exposed to anaerobic and aerobic conditions, which favours a certain bacteria, which can accumulate more phosphorus than is required for their growth. For this phosphorus accumulation the bacteria need volatile fatty acids (VFA) to cover their energy demand, but normally there is a shortage in VFA in the incoming wastewater.</p><p>The main purpose of this master thesis work has been to create the best possible conditions in order to produce VFA by hydrolysis and fermentation of primary sludge. In this way the organic material in the incoming wastewater can be used in biological phosphorus removal.</p><p>The sludge temperature, total solids (TS) and retention time are regarded as important parameters for a successful biological phosphorus removal and a laboratory study was set up to investigate these conditions for the wastewater at the Hammarby Sjöstad experimental plant. These laboratory-scale hydrolysis experiments showed that high temperature and high TS favours VFA-production. The results have also shown that four to five days retention time is suitable at a process temperature higher than 23°C, but also that the retention time likely should be extended at lower temperatures.</p><p>In a full-scale process experiment, primary sludge was pumped from a primary clarifier to a hydrolysis tank and then back to the primary clarifier. The hydrolysis gave rise to increased VFA-production when TS was increased. A temperature difference between the primary sludge and the hydrolysis sludge of 3°C was observed. The reason behind the difference has not been determined, but is considered important, since the temperature affects the VFA-production. Further on, analyses with gas chromatograph (GC) have shown that acetate has been the most frequently occurring VFA, although significant levels of other VFA, such as propionate, has also been detected.</p><p>Phosphorus release tests in laboratory-scale, where phosphorus was released during an anaerobic phase and taken up during an aerobic phase, proved that biological phosphorus removal occurred at the full-scale experimental train.</p><p>The full-scale hydrolysis experiment has shown that the VFA contribution by the hydrolysis tank to the biological phosphorus removal was low. The main reason is that the sludge-flow through the hydrolysis tank has been insignificant compared to the incoming wastewater flow. The problem is most likely connected to the incoming wastewater characteristics, since the low share of suspended solids (SS) entailed that not enough organic material in the primary clarifier settled.</p> / I figur 57 på sidan 76 stämmer inte trendlinjernas ekvationer i den tryckta versionen. Dessa är nu korrigerade i den elektroniska versionen, så att rätt ekvationer finns i den aktuella figuren.

Research performed at the Division of Environmental Microbiology has over the last years resulted in the isolation of possible bacterial key-organisms with efficient nutrient removal properties (Comamonas denitrificans, Brachymonas denitrificans, Aeromonas hydrophila). Effective use of these organisms for enhanced nutrient removal in wastewater treatment applications requires the strains to be retained, to proliferate and to maintain biological activity within theprocess. This can be achieved by immobilization of the organisms using an appropriate system.Two putative immobilization systems, agar entrapment and biofilm formation, wereassessed. Surface attached biofilm growth provided better results with respect to cell retention,proliferation and microbial activity than immobilization in agar beads. Thus, biofilm physiology was further characterized using simplified systems of single, dual or multi strain bacterial consortia containing the key-organisms as well as other wastewater treatment isolates. Mechanisms for initial adherence, biofilm formation over time, dynamics and characteristics of extracellular polymeric substances (EPS) and exopolysaccharides, nutrient removal activity as well as the effect of bacterial interactions were investigated. The results showed that all theassessed bacterial strains could form single strain biofilm providing that a suitable nutrientsupply was given. Production of EPS was found to be critical for biofilm development and both EPS and polysaccharide residue composition varied with bacterial strain, culture conditions and biofilm age. Denitrification and phosphorus removal activity of the keyorganisms was maintained in biofilm growth. Co-culturing of two or more strains resulted in both synergistic and antagonistic effects on biofilm formation as well as the microbial activitywithin the biofilm. Bacterial interactions also induced the synthesis of new polysaccharideswhich were not produced in pure strain biofilms.The complexity of single and mixed strain biofilm development and the implications of interactions on biofilm performance were underlined in this study. The data presented can be useful for modeling of biofilm systems, serve as a tool for selection of bacterial strain combinations to use for bioaugmentation/bioremediation or provide a base for further experiment design. / QC 20100622

No description available.

Hammarby Sjöstad is a new district of southern Stockholm built with focus on reduced environmental impact by recirculation of materials and sustainability. The environmental goals aim to cut the water consumption by half and a separate storm water treatment. Thus, the wastewater will be more concentrated and will originate from the households only. The Sjöstad project includes the idea of a local treatment plant for the household wastewater. To evaluate this possibility, Sjöstadsverket, an experimental treatment plant was constructed. New wastewater treatment processes are tested and evaluated and compared to conventional methods including both aerobic and anaerobic treatment processes. One of the aerobic treatment processes includes enhanced biological phosphorus removal (EBPR or Bio-P) as the method for the removal of phosphorus. In biological phosphorus removal the wastewater is alternately being exposed to anaerobic and aerobic conditions, which favours a certain bacteria, which can accumulate more phosphorus than is required for their growth. For this phosphorus accumulation the bacteria need volatile fatty acids (VFA) to cover their energy demand, but normally there is a shortage in VFA in the incoming wastewater. The main purpose of this master thesis work has been to create the best possible conditions in order to produce VFA by hydrolysis and fermentation of primary sludge. In this way the organic material in the incoming wastewater can be used in biological phosphorus removal. The sludge temperature, total solids (TS) and retention time are regarded as important parameters for a successful biological phosphorus removal and a laboratory study was set up to investigate these conditions for the wastewater at the Hammarby Sjöstad experimental plant. These laboratory-scale hydrolysis experiments showed that high temperature and high TS favours VFA-production. The results have also shown that four to five days retention time is suitable at a process temperature higher than 23°C, but also that the retention time likely should be extended at lower temperatures. In a full-scale process experiment, primary sludge was pumped from a primary clarifier to a hydrolysis tank and then back to the primary clarifier. The hydrolysis gave rise to increased VFA-production when TS was increased. A temperature difference between the primary sludge and the hydrolysis sludge of 3°C was observed. The reason behind the difference has not been determined, but is considered important, since the temperature affects the VFA-production. Further on, analyses with gas chromatograph (GC) have shown that acetate has been the most frequently occurring VFA, although significant levels of other VFA, such as propionate, has also been detected. Phosphorus release tests in laboratory-scale, where phosphorus was released during an anaerobic phase and taken up during an aerobic phase, proved that biological phosphorus removal occurred at the full-scale experimental train. The full-scale hydrolysis experiment has shown that the VFA contribution by the hydrolysis tank to the biological phosphorus removal was low. The main reason is that the sludge-flow through the hydrolysis tank has been insignificant compared to the incoming wastewater flow. The problem is most likely connected to the incoming wastewater characteristics, since the low share of suspended solids (SS) entailed that not enough organic material in the primary clarifier settled. / I figur 57 på sidan 76 stämmer inte trendlinjernas ekvationer i den tryckta versionen. Dessa är nu korrigerade i den elektroniska versionen, så att rätt ekvationer finns i den aktuella figuren.