In this study photoelectrocatalytic technology has been combined with fuel cell technology in an attempt to provide a stand alone water polishing device to be applied to the water purification industry. Tungsten trioxide was chosen as the photoelectrocatalyst to be applied to the fuel cell membrane electrode assembly (MEA). In this thesis two possible WO₃-based photoanodes were studied. Firstly a Nafion-loaded WO₃ photoanode utilising the state of the art proton conductor Nafion in the MEA. The second WO₃-based photoanode was synthesised by a sol-gel method with a view to being directly sintered onto a not yet developed solid state MEA containing a proton conductive glass. In both methods electrochemical studies were undertaken with both WO₃ based photoanodes deposited on fluorine doped tin oxide glass (FTO). The WO₃ catalysts were studied by X-ray diffraction, Raman spectroscopy, Nitrogen adsorption and UV-visible spectroscopy. Electrochemical studies included cyclic voltametry and linear sweep voltametry under illumination to ascertain the photocurrent densities of the photoanodes and hence their ability to degrade water borne contaminants. The underlying materials properties were explored as well as the nature of the deposition to gain insight into the mechanisms responsible for effective photoelectrocatalytic activity. The Nafion-loaded WO₃ was applied to a Nafion membrane based MEA and utilised in a photoelectrocatalytic fuel cell. This was studied for possible application under self sustaining conditions for application in the water industry.

This particular work is proposed as a test of the expedience of using the fluorescent-antibody technique as a method for enumeration and identification of certain strains of B. cereus that have been found to be effective in preventing taste and odor in water supplies resulting from certain Actinomycete blooms.

Vatten- och energiförbrukning är ett av mänsklighetens största nuvarande och framtida problem då världens vattenkonsumtion ständigt ökar på grund av bättre levnadsstandard samt ständigt ökande population och industrialisering. Förorenat vatten orsakar sjukdomar, sänkt livstid, reducerad sanitet och försämrad hälsa. Att rena vatten på ett energi- och miljöeffektivt sätt så att det kan återanvändas är därför ett måste för en hållbar framtid. En undersökning av koaguleringsförmågan för ett antal utvalda organiska föreningar via elektrokoagulation har utförts hos företaget Axolot Solutions AB. Axolot Solutions AB är ett företag som arbetar med rening av industriella vatten med elektrokemiska metoder, framförallt elektrokoagulation. De organiska föreningar som undersökts har delats in i grupperna sockerarter (maltos, raffinos, glukos samt laktos), organiska syror (myrsyra, citronsyra, hexansyra, smörsyra, oktansyra), alkoholer (1-propanol, 2-propanol), fettsyror (lecitin) och övriga (formaldehyd, vanillin, nonylfenol, α-pinen). Även ett industriellt vatten från en barkavvattningsprocess har undersökts samt modellvatten av ämnena xylan och lignin som kan hittas i barkvatten. Reningsförmågan av processen har undersökts genom att mäta COD halter före och efter behandling med ett kontinuerligt elektrokoagulationssystem. Varje förening har undersökts vid fyra olika initial pH: 4, 6, 7,5 och 9 och dessutom såväl järnanod och aluminiumanod testats. Även olika strömstyrkor har undersökts för ett par av de organiska föreningarna. Resultaten visar ingen COD reduktion för vatten innehållande xylan, sockerarter, organiska syror och alkoholer. Tekniken visade mycket god reduktion av ämnena: lecitin (85,5%) och lignin (98,1%). En mindre reduktion skedde även för vatten innehållande nonylfenol (33,6%), α-pinen (42,1%), och barkvatten (21,5%). En reduktion av COD skedde även för vanillinvatten med initial pH 4 vid användandet av aluminiumanod, detta var dock det enda vattnet innehållande vanillin som påverkades. Det går inte att dra någon generell slutsats kring vilket initial pH och vilken anod som bör användas vid elektrokoagulation då den mest effektiva anordningen inte är densamma för de olika undersökta föreningarna. / Water- and energy consumption is one of humanities biggest current and future problems because of ever increasing global water consumption and because of better living conditions, increasing population and industrialization. Polluted water results in diseases, reduced life expectancy, sanitation and reduced overall health of those affected. Purifying water in an energy and environmentally effective way is therefore a must for a sustainable future. A study of the coagulation capabilities for a select number of organic compounds by electrocoagulation has been performed at Axolot Solutions AB. Axolot Solutions AB is a company developing electrochemical water treatment solutions, with a focus on the electrocoagulation process. The compounds that have been studied are sugars (raffinose, maltose, glucose, lactose), organic acids (formic acid, citric acid, hexanoic acid, butyric acid, octanoic acid), alcohols (1-propanol, 2-propanol), fatty acids (lecithin), others (formaldehyde, vanillin, nonylphenol, α-pinene). Industrial water coming from a debarking process was also investigated as well as two compounds that are often present in this type of water, xylan and lignin. The treatment efficiency was determined by measuring the COD values of the investigated water before and after the electrocoagulationprocess. Each compound was studied by using an iron anode and an aluminum anode at four different initial pH values: 4, 6, 7.5, 9. Different current densities were also studied for some of the investigated compounds. The results show no COD reduction for sugars, alcohols, organic acids and xylan. The process resulted in large reductions of the compounds lecithin (85.5%) and lignin (98.1%). A lesser reduction was found for the waters containing: nonylphenol (33.6%), α-pinene (42.1%) and barkwater (21.5%). A reduction of COD was also found in the water containing vanillin with an initial pH of 4 that was treated with an aluminum anode was affected. The most efficient setup for the investigated compounds varies. For that reason, no conclusion as to which initial pH and anode that should be for electrocoagulation processes in general can be drawn.

This thesis aims to investigate and assess the future conditions for Volvo GTO Umeå after the installation of a new pre-treatment facility. The treatment method used is physical-chemical precipitation. Its function is to precipitate contaminants such as nickel, zinc and phosphorus, make them flocculate by adding a coagulant and separate the flocs by sedimentation. An investigation was carried out at the Volvo plant to locate the major inflow of waste water. These major inflows was analyzed and future scenarios was predicted by estimating a lower pre-treatment flow volume. The future scenarios showed that the volume and content will be greatly lowered. This will change many of the treatment plants performance factors, such as residence time, metal ion concentration and how much chemicals needed to treat the contaminants. Volvos physical-chemical precipitation plant was compared to the best available technique document drawn up in the framework of the implementation of the Industrial Emission Directive (2010/75/EU). The findings in the comparison showed that the Volvo plant works at a desirable degree and that the plant itself is considered best available technique when treating the current and future contaminants. Thus the physical-chemical precipitation technique can be used to treat the future waste water flows if the treatment plants performance factors are adjusted for.

Esse trabalho teve como objetivo avaliar a viabilidade técnica e econômica da regeneração de coagulantes a partir do lodos gerados em ETA\'s. Foi considerado que o coagulante regenerado será empregado em sistemas de tratamento de esgotos. A regeneração de coagulante consiste basicamente em promover uma alteração no pH do lodo, de forma que os hidróxidos metálicos presentes são solubilizados. A fase líquida com alta concentração de metais é então separada, constituindo o coagulante regenerado. Consequentemente, essa tecnologia propicia a recuperação de um recurso, que é o coagulante, e a redução de lodo. Para a verificação da viabilidade técnica foram realizados ensaios de acidificação em escala de bancada com lodos das ETA\'s Guaraú e Rio Grande, visando o estudo das condições de regeneração, da qualidade do coagulante produzido e do lodo restante. Foi verificado que do ponto de vista técnico a regeneração de coagulantes é uma alternativa possível, gerando um coagulante aproximadamente 100 vezes mais diluído que os comerciais, mas com desempenho satisfatório na aplicação no tratamento de efluentes de reator UASB. As reduções médias de sólidos em suspensão nos lodos utilizados foram de 28% e 53%. A avaliação econômica foi realizada considerando uma ETA com características similares à ETA Rio Grande, com um sistema de regeneração em funcionamento. Foi verificado que considerando as reduções de custos decorrentes da diminuição de lodo a ser tratado e disposto, o custo de produção do coagulante regenerado é muito próximo ao custo do coagulante comercial. Portanto, conclui-se que hoje em dia essa tecnologia deve ser considerada como uma alternativa potencialmente viável dos pontos de vista técnico e econômico para o tratamento e reaproveitamento de lodo de ETA\'s. / The primary goal of this work was to evaluate the technical and economical feasibility of coagulant recovery from water treatment plant sludges, considering that the recovered coagulant is going to be used in wastewater treatment plants. The coagulant recovery technology consists in change the sludge pH, in order to solubilize the present metal hydroxides. The liquid phase with high metals concentrations is then separated, becoming the recovered coagulant. This technology provides a resource recovery, which is the coagulant, and also a reduction in the amount of sludge that needs to be treated and disposed. To verify the technical feasibility, acidification bench tests were conduced using sludges from Guaraú e Rio Grande water treatment plants, in order to study the regeneration conditions, the recovered coagulant quality and the remaining sludge. From the technical point of view, it was verified that coagulant recovery is a possible alternative, producing a coagulant 100 times more diluted than the commercial coagulant, but with a satisfactory behavior in the treatment of UASB reactor effluent. The suspended solids average reductions in the Rio Grande and Guaraú water treatment plants sludges were 53% and 28%, respectively. The economical evaluation was done using the results obtained in the bench tests and considering a water treatment plant similar to Rio Grande. It was verified that considering the costs decrease due to the sludge reduction, the recovered coagulant production cost was very similar to commercial coagulants cost. Thus, it was concluded that nowadays this technology must be considered as a potential alternative for the treatment and reuse for water treatment plant sludges, regarding to the technical and economical aspects.

A proposta deste trabalho foi a concepção de um modelo para o dimensionamento otimizado de sistemas para tratamento de água baseados na tecnologia de Ultrafiltração com membranas de fibra-oca pressurizadas. O modelo relaciona o comportamento das membranas com a qualidade da água bruta através de resultados de ensaios em unidade piloto ou de bancada e equações de bloqueio de poros. A validação desta relação foi realizada através da análise dos dados de uma planta piloto operada em dois períodos distintos em regimes de fluxo variando de 60 a 70L/m².h e alimentada com água bruta proveniente de um manancial de superfície. Os resultados apontaram para a predominância do mecanismo de obstrução através da formação de torta e indicaram uma boa aderência das equações do modelo físico à realidade observada. Variáveis econômicas foram incorporadas ao modelo de forma a permitir a otimização através da busca do mínimo custo total de propriedade. Uma análise de sensibilidade demonstrou que os parâmetros de projeto mais impactantes no custo total, quantidade de membranas, duração do ciclo de filtração e duração do ciclo de contralavagem, podem variar seu peso em diferentes regiões do mundo influenciando o dimensionamento. Outras variáveis de projeto como a vazão de ar de limpeza demonstraram ser pouco significantes para a redução do custo total. A otimização do modelo foi realizada através de um algoritmo de busca numérica para as variáveis de duração do ciclo de filtração e quantidade de membranas, os resultados a partir das informações colhidas na planta piloto levaram a um projeto arrojado, porém dentro das recomendações gerais dos fabricantes de membranas. Como conclusão é possível afirmar que o modelo de dimensionamento do projeto é capaz de reduzir os custos totais de uma estação de tratamento de água baseada na tecnologia de ultrafiltração além de demonstrar potencial para a otimização dinâmica de plantas já instaladas. / The goal of this work was the development of an optimal design model for water treatment plants based in the pressurized hollow-fiber ultrafiltration membrane technology. The model uses operational data from pilot plants or bench scale units as input and pore blocking equations to predict the behavior of the membranes. The correlation between the fouling model adopted and the pilot plant results was evaluated using a pilot plant operated in two different time frames with flux rates from 60L/m²h to 70L/m²h and fed with raw water from a lake. The results from this validation have shown that the major fouling mechanism is the cake filtration and the theoretical curves had a good fitting with the operational data. To allow the cost optimization, economic variables were added to the model. A sensitivity analysis demonstrated that the most significant design parameters on the overall cost were the membrane area, the duration of the filtration cycle and the duration of the backwash cycle. According to the analysis, since the costs of the commodities and membranes are different from a region to the other, the optimal system design will also be different. Other design parameters like the membrane aeration rate have shown almost no impact on the total operating cost. The model optimization for the membrane quantity and the filtration cycle duration was based on bi-dimensional discrete numeric algorithm. The results from the optimization using the pilot plant data were compatible with the typical ranges and limits proposed by the membrane manufacturers. The design model proposed was able to reduce the total costs of new plants and demonstrated a good potential for the dynamic optimization of existing plants.

No description available.

"The goals of this study were (1) to evaluate the impacts of pesticides used for mosquito control on drinking water and (2) to investigate the removal of permethrin from water using activated carbon. A review of current literature on pesticide usage, toxicity, occurrence in the environment, and treatment techniques to remove pesticides from drinking water was conducted. The focus of the literature review was on pesticides used for mosquito control. Permethrin is a synthetic pyrethroid insecticide used extensively in the United States (US) for mosquito control and in agriculture, with approximately 2 million pounds applied each year. Permethrin was selected for investigation based on its widespread use in the US, its inclusion on the Contaminant Candidate List 3 (CCL3), its health hazards, and the lack of previous research on the removal of permethrin from drinking water. The removal of permethrin from water using powdered activated carbon (PAC) was investigated. Equilibrium adsorption experiments to assess removal of cis-, trans-, and total permethrin were conducted using two types of PAC (WPH 650 and WPH 1000). Initial total permethrin concentrations ranged from 2.0 to 4.6 ug/L. PAC doses ranged from 0.0 to 10 mg/L. Results showed that PAC addition is an effective method for removing permethrin from water. Total permethrin concentrations were reduced by 38% with 0.05 mg/L of PAC WPH 650, and reduced to below the detection limit with 3 mg/L of PAC WPH 650. Total permethrin concentrations were reduced by 35% with 0.05 mg/L of PAC WPH 1000 and by 83% with 5 mg/L of PAC WPH 1000. Results for cis- and trans- permethrin were similar. The Freundlich isotherm model provided appropriate fits to the data with an R-squared value of 0.91 for both WPH 650 and WPH 1000."

One billion of the poorest people in the world today do not have access to improved drinking water. Without treatment, fecal contamination results in an overwhelming disease burden. A long term best practice solution will take decades to implement. In the meantime, approximately 5 million children under five die each year from gastrointestinal diseases. This tragedy can be alleviated by household water treatment. Household Water Treatment and safe Storage systems (HWTS) provide an interim solution. While many low cost and simple technologies exist, none of them are effective against high suspended solids concentrations (>50 NTU). Previous short-term field research by others has considered modifying a BioSand water Filter (BSF), to include pretreatment through an upper sand layer in order to extend the run cycle of the primary filter, enabling complete ripening to occur. In this research program, one control and twelve configurations of modified filters were setup in the laboratory. Water was chemically conditioned to provide worst case scenario treatment by adjusting pH, TDS, and particle dispersion. Sample water was passed through each filter daily, and monitored for DO, turbidity, flow rate, and E. coli concentrations. The results indicate that pretreatment is not necessarily beneficial under all water quality conditions. Recommendations include a description of conditions under which the modification may be beneficial, and optimized pretreatment design criteria. Regardless of water quality conditions, it was found that changing the operational guidelines for filter use can significantly improve treatment efficiency, without complicating the filter design. Design guidelines for an unmodified filter coupled with operational guidelines are provided, in order to obtain sufficient quantities of the best possible water quality under high turbidity conditions. This will enable the BSF to be used in high turbidity conditions and still significantly improve the drinking water quality. It is hoped that this will decrease the disease burden and loss of life in many of the world's poorest communities.

The thesis work is done at STENA Recycling Halmstad. The recycling facility has a yearly capacity to process 110.000 tonnes of material. There is an internal water system that circulates water to each of the separation processes and cleans before recirculation. Due to environmental concerns and government regulations the internal water cannot be let out of the facility. In addition, the internal water treatment system at STENA was not efficiently cleaning the internal water causing frequent plant maintenance issues.    The aim of the thesis is to improve the quality of the cleaned water from the internal water system. Qualitative data such as interviews and observations were combined with quantitative data that is measurements to reach the results, using a method called triangulation. Six Sigma (DMAIC) model was followed for the work execution.   The internal water treatment has five process steps. Five improvements are identified, implemented and evaluated. The thesis work goal of less than 2% dirt in the clean water is achieved by improving the overall performance of the cleaning system by 48.5% after implementing improvements. As a part of the last phase of six sigma approach which is control phase, an operation manual is developed to maintain the internal water treatment system.