No description available.

As fontes hídricas disponíveis para o consumo humano vêm sendo comprometidas. Para resolver este problema, várias técnicas de detecção de contaminação fecal foram desenvolvidas. Em 1982, Manja e colegas desenvolveram método H2S que é simples, rápida e de baixo custo e detecta bactérias produtoras de H2S e, assim, a contaminação fecal. Neste trabalho foi analisada a eficácia de detecção de micro-organismos produtores de H2S frente a adição de L-cistina (125mg/L e 250mg/L) e desoxicolato de sódio (DS) (0,1% e 0,3%) e na presença de bactérias não produtoras de H2S para verificar se a presença destas bactérias interferem na detecção dos isolados H2S+. Assim, comparou-se o teste H2S com a membrana filtrante e o Colilert®. Os resultados deste estudo indicam que o meio H2S com adição de 0,3% de desoxicolato de sódio se mostrou mais rápido e sensível. Quando comparado com outras metodologias clássicas, o meio com 0,3% apresentou uma ligeira queda na sensibilidade mas o método H2S se mostrou mais sensível que o Colilert. / Water supply for human consumption have been compromised. Several detection methods for fecal contamination have been developed to solve this problem. Manja and co-workers (1982) developed a simple, fast and low-cost method for fecal contamination based on detection of sulfate-reducing bacteria, the H2S method. This work aimed to analyse the detection efficiency of the H2S method under different conditions: with L-cystine (125mg/L e 250mg/L) and sodium deoxycholate (0.1% e 0.3%). Also, non-sulfate-reducing bacteria interference were evaluated. Comparison tests were made through membrane filtration and Colilert®. Our results indicate a faster and more sensible for the 0.3% sodium deoxycholate condition. Compared to other classic methodologies, the 0.3% sodium deoxycholate condition slightly decrease the sensibility. However the H2S method was more sensitive than the Colilert one.

Submitted in fulfilment of the requirements for the Degree of Master of Engineering, Durban University of Technology, 2017. / In this research, the woven fibre microfiltration (WFMF) fabric which is produced locally in South Africa is used as a membrane material. It is cheaper in price in comparison with the current commercial membrane materials that are in use. The WFMF is also more robust when compared with the commercial membrane materials thus is able to withstand harsh working conditions. From previous studies on the WFMF, it has been shown that it can be used as a membrane material without any compromise to permeate quality. This research seeks to optimize the working conditions of this membrane material (WFMF) with an aim of achieving lower running costs and better anti fouling strategies in comparison to the commercial MBRs. The objectives and aims of this research was to come up with a MBR system whose running cost is lower than that for the commercial systems, which can be adapted for use in any environment, especially in the hardship regions where its robustness would be an added advantage. The performance of the WFMF submerged MBR was also optimised including antifouling operating regimes. This study was done in a pilot plant that was set up at Veolia wastewater treatment plant, Durban Metro Southern Works. The feed water for the pilot plant was pumped from the return activated sludge mixing chamber by means of a submersible pump. The MLSS concentration of the feed water was about 12 g/l. The various investigations that were conducted in the course of this research included the effect of spacing between membrane modules, relaxation steps and frequencies, evaluation of aeration rates and evaluation of coarse vs. fine bubbles which were all aimed at optimizing the performance of the immersed WFMF MBR. The permeate was checked for turbidity and COD levels to ensure that they were within the accepted water standards. From the experiments it is shown that the critical flux increased with an increase in aeration rate which is in concurrence with the literature and a starting flux of 30 LMH was chosen for the running of the pilot plant for the various experimental runs to be carried out. For the pipe diffuser height effect experimental run, the best results were achieved at a height of 5 cm below the membrane modules and the use of a pipe diffuser gave better results than the use of a disc diffuser. For the membrane module spacing effect the best results were obtained at the smallest possible width i.e. 3.5 mm. The best relaxation step sequence was found to be 9 mins on and 1 min off. COD, turbidity and DO was continuously determined during the course of the experimentation. Further studies should be done on use of the disc diffuser with increased surface area of aeration holes and also hole sizes of smaller diameters to check on its effectiveness as a means of reducing fouling on the membrane surface. / M

Les résidus forestiers et agricoles, également appelés résidus lignocellulosiques, constituent de par leur quantité et leur structure un potentiel unique pour la production d’énergie et de molécules d’origine renouvelable, afin de pallier à la raréfaction des hydrocarbures fossiles ainsi qu’aux problèmes environnementaux liés à l’utilisation de ceux-ci. Les biomasses lignocellulosiques sont constituées principalement de cellulose, hémicelluloses et lignines. Le fractionnement et la purification de ces trois constituants est nécessaire à leur valorisation comme produits de substitution des hydrocarbures fossiles. Cette étude s’est tout d’abord attachée à la description et la compréhension des fractionnements chimiques acides et alcalins de la lignocellulose et aux voies de purification qui leur sont actuellement associées. Les travaux expérimentaux ont été réalisés à partir de deux matières premières : la bagasse de canne à sucre et le tourteau de tournesol. Une caractérisation fine de ces matières premières ainsi que des extraits acides et alcalins obtenus à partir de ces matières a été réalisée. Les étapes de purification se sont focalisées sur l’extrait alcalin de bagasse obtenu en conditions douces. En effet, la bagasse de canne à sucre peut être considérée comme un bon modèle de biomasse lignocellulosique, et la purification d’extraits alcalins lignocellulosiques obtenus en conditions douces a été peu étudiée malgré l’intérêt de ce procédé de fractionnement. La filtration membranaire et la chromatographie d'élution sur résine échangeuse de cation ont été évaluées séparément puis en association, afin de séparer les cinq grandes familles de molécules constitutives de l’extrait : des oligomères de lignines, des oligomères de sucres, des monomères phénoliques, de l’acide acétique et des sels inorganiques. Des essais d’ultrafiltration sur plusieurs membranes en faisant varier divers paramètres de filtration ont permis de déterminer que les oligomères de lignine et de sucres, récupérés dans le rétentat, sont séparés des monomères phénoliques, de l’acide acétique et des sels inorganiques, récupérés dans le perméat. Une membrane en fibres creuses de 10 kDa en polysulfone a présenté les meilleures performances de séparation et a été retenue pour les essais suivant en mode concentration et diafiltration. Des essais de chromatographie d'élution avec de l’eau pour éluant en testant plusieurs résines cationiques fortement acides ont montré qu’une fraction très pure d’oligomères de lignines et de sucres peut être obtenue avec une résine de type macroporeuse, alors qu’une résine de type gel a permis la séparation de monomères phénoliques entre eux en fonction de la présence ou non dans leur structure d’une fonction carboxyle. A partir d’extrait alcalin de bagasse, un procédé intégré de purification a été développé combinant de la filtration membranaire puis de la chromatographie sur le perméat et de la précipitation par ajout d’acide sur le rétentat. Il en a résulté l'obtention de quatre fractions purifiées : les monomères phénoliques avec fonction carboxyle, les sels inorganiques et les monomères phénoliques sans fonction carboxyle, les oligomères de lignine, et les oligomères de sucres. / Agricultural and forestry residues, also known as lignocellulosic residues, have a unique potential based on their quantity and structure for the production of renewable energy and molecules, inorder to solve the issues raised by the increasing scarcity of fossil hydrocarbons and the environmental disorder caused by their use. Lignocellulosic biomasses are essentially made ofcellulose, hemicelluloses and lignin. Fractionation and purification of these three compounds are necessary for their valorization as substitutes of fossil hydrocarbons. In the first place, this studydescribed the chemical fractionation of lignocellulose under acidic and alkaline conditions, and their related purification pathways. The experimental work was carried out on two raw materials:sugarcane bagasse and sunflower oil cake. A thorough characterization of the raw materials as well as the acid and alkaline extracts produced from these materials was performed. The purification steps focused on the sugarcane bagasse mild alkaline extract. Indeed, sugarcane bagasse can be considered a model lignocellulosic biomass and the purification of lignocellulosicmild alkaline extract has not been widely studied despite the numerous assets of this fractionation process. Membrane filtration and elution chromatography on strong acid cationic exchange resins were assessed individually then combined, for the separation of the five main pools of molecules that constitute the extract: lignin oligomers, sugar oligomers, phenolic monomers, acetic acid and inorganic salts. Ultrafiltration trials run on several membranes under various filtration conditions showed that lignin and sugar oligomers, recovered in the retentate, were separated from phenolicmonomers, acetic acid and inorganic salts, recovered in the permeate. A hollow fiber membrane of 10 kDa in polysulfone exhibited the best separation performance and was selected for further trials in concentration and diafiltration modes. Elution chromatography tests using water as eluent and various strong acid cationic exchange resins resulted in the production of a very pure lignin andsugar oligomers fraction with a macroporous-type resin, whereas a gel-type resin led to the separation of phenolic monomers from each other depending on the presence or absence in their structure of a carboxyl group. From a sugarcane bagasse mild alkaline extract, an integrated purification process was developed combining membrane filtration then chromatography on the permeate and precipitation by acid addition on the retentate. It resulted in the production of four purified fractions: phenolic monomers with a carboxyl group, inorganic salts and phenolicmonomers without carboxyl group, lignin oligomers, and sugar oligomers

This thesis investigates the potential of biomethane production in India, the impact of its integration into the energy mix, and the corresponding Greenhouse Gases (GHG) emission and potential reduction. India, with its huge population and being an agriculturally rich country, produces gigantic amounts of biodegradable waste from various sources such as Municipal Solid Waste (MSW),agricultural waste, animal husbandry, sugar industry, etc. Three different end-use scenarios: electricity generation, cooking fuel, and transportation fuel—are assessed in order to determine the decree to which current fossil fuels may be replaced and the net amount of greenhouse gas emissions that are saved by using this biomethane. The total biomethane generation potential according to the study conducted by the Ministry of New and Renewable Energy (MNRE) is 25.6 Billion Metric Standard Cubic Meters (BMSCM) and with the most efficient upgrading technology available (3-stage membrane filtration) the useful potential is 25.4 BMSCM. The electricity that can be produced from the biomethane potential available is 159.1 TWh, which corresponds to the optimistic value of GHG emission reduction of 89million tons. When used as a cooking fuel, biomethane can contribute immensely to satisfying the final thermal needs of India. It can satisfy more than half the combined total thermal energy from Compressed Natural Gas (CNG) and Liquefied Petroleum Gas (LPG) consumed in India and, at the same time, reduce 46.2 million tons of GHG emissions caused by it. The transportation sectoris the most suited and easy to adapt as an end-use application for biomethane. It was observed that biomethane as a replacement for Petrol for road transportation fuel presents the best scenario, since biomethane can reduce more than 71% of its consumption and respectively reduce more than 57 million tons of GHG emission, which is the second highest after electricity production. This thesis puts up a strong case to look at biomethane as a very important fuel towards India’starget to be net zero by 2070 and its plans to be self-reliant. Moreover, biomethane production usingthe path of anaerobic digestion provides not only a renewable source of energy but also food security with digestate being used as fertilizer and an opportunity to address the impact of climate change by preventing the emission of methane in the atmosphere which has a global warming potential of28 and burning of agricultural waste in the open field. Eventually, the production of biomethane prevents soil, air and water pollution. / Denna avhandling undersöker potentialen för biometanproduktion i Indien, effekterna av dess integration i energimixen och motsvarande utsläpp och potential för växthusgaser (GHG). minskning. Indien, med sin enorma befolkning och är ett jordbruksrikt land, producerar gigantiska mängder biologiskt nedbrytbart avfall från olika källor som kommunalt fast avfall (MSW), jordbruksavfall, djurhållning, sockerindustri, etc. Tre olika slutanvändningsscenarier: el produktion,matlagningsbränsle och transportbränsle – utvärderas för att fastställa till vilket dekret nuvarande fossila bränslen får ersättas och nettomängden växthusgasutsläpp som sparas genom att använda denna biometan. Den totala biometangenereringspotentialen enligt studien utförd av ministeriet för ny och förnybarenergi (MNRE) är 25,6 miljarder metriska standardkubikmeter (BMSCM) och med den mest effektiva uppgraderingstekniken som finns tillgänglig (3-stegs membranfiltrering) är den användbara potentialen 25,4 BMSCM. Den el som kan produceras från den tillgängliga biometanpotentialen är 159,1 TWh medan det optimistiska värdet av växthusgasutsläpp som är möjligt med användning av biometan för elproduktion är 89 miljoner ton. När biometan används som matlagningsbränsle kan det bidra oerhört mycket för att tillfredsställa Indiens slutliga termiska behov. Det kan tillfredsställa mer än halva finalen termisk energi som förbrukas i Indien och samtidigt samma miljon ton i utsläpp av växthusgaser som orsakas av den. Transportsektorn är den mest lämpade och lätta att anpassa som slutanvändningsprogram för biometan. Det observerades att biometan som ersättning för bensin som transportbränsle är det bästa scenariot eftersom biometan kan minskamer än 71 % av sin förbrukning och respektive minska mer än 57 miljoner ton växthusgasutsläpp, vilket är det näst högsta efter elproduktion. Den här avhandlingen ger ett starkt argument för att se biometan som ett mycket viktigt bränslemot Indiens mål att vara nettonoll år 2070 och dess planer på att vara självförsörjande. Dessutom ger biometanproduktion genom att använda vägen för anaerob rötning inte bara en förnybar energikälla utan också livsmedelssäkerhet med rötgas som används som gödningsmedel och en möjlighet att ta itu med effekterna av klimatförändringar genom att förhindra utsläpp av metan i atmosfären som har en global uppvärmningspotential på 28 och förbränning av jordbruksavfall på det öppna fältet. Så småningom förhindrar produktionen av biometan mark-, luft- och vattenföroreningar.

M. Tech. (Chemical Engineering) / The usual target of an upgrading process using membrane is to produce a retentate stream, the product, with high CH4 concentration. This work presents a simulation of two possible membrane configurations, single stage without recycle (SSWR) and double stage with permeate recycle (DSPR), of an existing operational biogas upgrading plant. The simulation was conducted using ChemCAD and AlmeeSoft gas permeation software to investigate the performance of the configurations on product purity, recovery and required compressor power with a view to determine the optimal operational conditions for maximising the concentration of CH4 and its recovery. Thereafter, an economic assessment on the optimal configuration was conducted to determine the gas processing cost (GPC), the profitability of producing biomethane and cost-benefit of utilising biomethane as a vehicular fuel. The simulation was validated against plant data with a maximum percentage error of 2.64%. Increasing CO2 in feed reduced product recovery and purity. Increasing feed pressure and selectivity increased product recovery and purity up to the pressure limit of the membrane module. Increasing feed flow rate increased product recovery but reduces purity. In both configurations, increasing CO2 in the feed and increasing feed pressure increased the GPC. However, increasing feed flow rate reduced the GPC. The overall performance of DSPR configuration was much higher due to increased trans-membrane area available for separation. At optimal conditions, a product purity of 91% and 96% CH4 recovery was achieved from the initial plant result of 87.2% product purity and 91.16% CH4 recovery. The total compression duty was 141 kW. The GPC was $0.46/m3 of biomethane. The cumulative discounted NPV, IRR and BCR for producing biomethane was R15,240,343, 22.41% and 2.05 respectively, with a break-even in the 5th year after plant start-up considering a prime lending rate at 9%. Using CBG instead of gasoline saves 34% of annual fuel cost with a payback period of one year and three months for the cost of retrofitting the vehicle.

M.Tech. (Civil Engineering) / This study presents work on the design and construction of three dual-chamber microbial fuel cells (MFCs) using a sandwich separator electrode assembly (SSEA) and membrane cathode assembly (MCA) for the dual purposes of energy generation from domestic wastewater and wastewater treatment. MFC1 was designed using an improvised SSEA technique (i.e. a separator electrode membrane electrode configuration, SEMEC) by gluing a sandwich of anode, membrane and a mesh current collector cathode to an anode chamber made from a polyethylene wide-mouth bottle. The reactor was filled with 1500 mL of domestic wastewater and operated on a long fed-batch mode with a residence time of 3 weeks. The reactor was inoculated with a mixed culture of bacteria present in the wastewater stream. The aim was to study the impact of wastewater COD concentration on power generation and wastewater treatment efficiency. For MFC2 and MFC 3, cathodes were constructed using the MCA technique consisting of a membrane and a mesh current collector cathode, with the anode electrode at the opposite side of stacked Perspex sections used for the anode chamber. The impact of electrode material on current production was examined in this study. For MFC2 a mesh current collector treated with polytetrafluoroethylene (PTFE) and activated carbon (AC) functioned as the cathode, while the MFC3 cathode was an uncatalyzed mesh current collector. The two reactors were both filled with 350 mL of domestic wastewater...

Orientadores: Mirna Lucia Gigante, Rafael Jimenez-Flores / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-09-11T21:12:34Z (GMT). No. of bitstreams: 1 Costa_MarceladeRezende_D.pdf: 1269005 bytes, checksum: be9b972dd7766eba5cc6917dd666c5f0 (MD5) Previous issue date: 2008 / Resumo: O leitelho de soro é um subproduto do processamento de manteiga a partir do creme de soro. Esse subproduto lácteo contém fragmentos da membrana do glóbulo de gordura do leite (MGGL), material rico em componentes com funções nutricionais e efeitos benéficos à saúde, destacando-se os fosfolipídeos. O objetivo desse trabalho foi obter um ingrediente lácteo enriquecido em fosfolipídeos da MGGL a partir do leitelho de soro utilizando a associação de duas tecnologias de fracionamento: ultrafiltração e extração com fluido supercritico (EFS). O leitelho de soro foi submetido à ultrafiltração e a cinco diafiltrações a 25 °C e o retentado obtido foi seco em spray-dryer, obtendo-se o leitelho de soro em pó (LSP), o qual foi submetido a três ciclos de extração a 50 °C com dióxido de carb ono supercrítico. As matériasprimas, produtos finais e uma amostra comercial de leitelho tradicional em pó (LTP) foram analisados quanto a sua composição centesimal, teor de fosfolipídeos, perfis lipídico e protéico. Os leitelhos de soro em pó, submetidos ou não à EFS, e o LTP foram avaliados quanto ao tamanho de partículas e suas propriedades funcionais (solubilidade protéica e capacidade emulsificante) em pH 5 e 7. A filtração em membrana reduziu em 74 e 96% os teores de lactose e cinzas no retentado e aumentou os de proteínas, lipídeos e fosfolipídeos em 91, 190 e 300%, respectivamente. A EFS reduziu em 55,4% o teor de lipídeos, removendo exclusivamente lipídeos apolares, com isso aumentou em 71% o teor de fosfolipídeos no leitelho de soro em pó, resultando em um produto com 73% de proteínas, 21% de lipídeos, 3% de lactose, 3% de cinzas e 12% de fosfolipídeos, em base seca. As propriedades funcionais dos leitelhos de soro em pó, submetidos à extração supercrítica (LSP-EFS) ou não (LSP), foram pouco ou não afetadas pelo pH, enquanto o abaixamento de pH prejudicou as características do LTP, devido ao alto teor de caseínas nesse tipo de pó em relação aos de leitelhos de soro. Os pós em soluções (5% de proteína) apresentaram de 69 a 84% de suas partículas, em % volumétrica, entre 10 e 100 µm. A solução de LTP em pH 5 foi a que apresentou a maior quantidade de partículas acima de 100 µm. LSP e LSP-EFS apresentaram solubilidades protéicas em torno de 86 e 84%, respectivamente, independente do pH. O LTP teve a solubilidade reduzida de 86 para 73% quando o pH foi reduzido de 7 para 5. Em pH 7, as emulsões (20% óleo de canola, 1% proteína) de LSP e de LSPEFS apresentaram melhor estabilidade (IC de 0,2 e 0,4%, respectivamente) do a emulsão de LTP (IC de 3,0%). Em pH 5, a emulsão de LSP-EFS foi a que mostrou melhor estabilidade, apresentando um IC de 7%, valor cerca de 82% menor do que os das emulsões de LSP e LTP. Os leitelhos de soro em pó obtidos podem ser considerados ingredientes com características promissoras, associando propriedades tecnológicas, especialmente para uso em alimentos de baixo pH, e conteúdo de compostos potencialmente benéficos à saúde, principalmente após o tratamento com extração supercrítica / Abstract: OBTENTION OF DAIRY INGREDIENT ENRICHED IN POLAR LIPIDS FROM WHEY BUTTERMILK. Whey buttermilk is a by-product from the whey cream processing into butter. This dairy by-product contains milk fat globule membrane (MFGM) fragments, a material rich in components with nutritional functions and beneficial health effects, especially phospholipids. The objective of this research was obtaining a dairy ingredient enriched in MFGM phospholipids from whey buttermilk using the association of two fractionation technologies: ultrafiltration and supercritical fluid extraction (SFE). Whey buttermilk was submitted to ultrafiltration and five diafiltrations at 25 °C. The retentate was spray-dried and later s ubmitted to three cycles of extraction at 50 °C with supercritical carbon dioxi de. Raw materials, final products and a commercial traditional buttermilk powder sample (BMP) were analyzed for gross composition, lipid and protein profiles, and phospholipids content. Whey buttermilk powders, before and after the SFE, and the BMP had particle size and some functional properties (protein solubility and emulsifying capacity) evaluated in pH 5 and 7. Membrane filtration reduced in 74 and 96% lactose and ash contents in the retentate and increased proteins, lipids and phospholipids in 91, 190 and 300%, respectively. SFE reduced in 55.4% the lipids content, removing exclusively non-polar lipids, while increased in 71% the phospholipids content in whey buttermilk powder, resulting in a product with 73% of proteins, 21% of lipids, 3% of lactose, 3% of ash and 12% of phospholipids, in dry matter basis. Functional properties of the whey buttermilk powders, treated (WBP-SFE) or not through SFE (WBP), were little or not affected by pH, while dropping the pH impaired the BMP features, due the high casein content in this type of powder in relation to the ones from whey buttermilk. The powders in solutions (5% protein) presented from 69 to 84% of the particles, in volume%, between 10 and 100 µm. The BMP solution in pH 5 was the one with the biggest amount of particles above 100 µm. WBP and WBP-SFE showed protein solubilities around 86 and 84%, respectively, independent of pH. BMP had the solubility reduced from 86 to 73% when pH was reduced from 7 to 5. In pH 7, the emulsions (20% canola oil, 1% protein) of the WBP and the WBP showed better stability (CI of 0.2 and 0.4%, respectively) than the BMP emulsion (CI of 3.0%). When in pH 5, WBP-SFE emulsion had the best stability, presenting CI of 7%, value about 82% smaller than the ones of WBP and BMP emulsions. Whey buttermilk powders obtained in this work can be considered ingredients with promising features, combining technological properties, especially for use in low pH foods, and content of components with potential health benefits, mainly after the supercritical extraction treatment / Doutorado / Doutor em Tecnologia de Alimentos

Made available in DSpace on 2017-07-20T13:42:00Z (GMT). No. of bitstreams: 1 Juliano Almeida.pdf: 2689795 bytes, checksum: e2c63ba0cfcdfb76d39a3d5e44e5dcf9 (MD5) Previous issue date: 2017-04-20 / Considering the shortage of fresh water availability and an increased demand for water in the world, including Brazil, one of the alternatives for water supply are the water desalination system, which remove salts from brackish or seawater. The objective of this study was to evaluate the efficiency of treated water desalination system with production capacity of 1.0 m3 h-1 of treated water, installed in a water treatment plant of Sanepar (Water and Sanitation Company of the State of Parana), in Praia de Leste located in the coast of the state of Paraná, Brazil. In this study, the seawater was diluted with fresh water to make brackish water. The brackish water was prepared from the water mixture of the Pombas River, source of fresh water supply to the region, and sea water. The mixtures were performed to obtain concentrations of 1000 and 1500 mg L-1 of total dissolved solids (TDS). The system was composed of ultrafiltration (UF) as a pre-treatment to reverse osmosis (RO). Experiments were performed during 15 days for each TDS concentration of brackish water and TDS removal efficiencies were 99.0 and 99.1%, respectively. Besides TDS, other water quality parameters such as: electrical conductivity, turbidity, apparent colour, alkalinity, total hardness, calcium, magnesium, chlorides, sulphates and pH were monitored. Oxidation-reduction potential (ORP) and osmotic pressure, filtration rate and membrane recovery rate were also measured for the RO. The pilot plant system could remove all water quality parameters studied. / Com a escassez da disponibilidade de água doce e o aumento da demanda de água no mundo e também no Brasil, uma das alternativas para o suprimento de água são os sistemas de dessalinização de água, que removem os sais da água salobra ou salgada. Este trabalho teve como objetivo avaliar a eficiência de um sistema piloto de dessalinização de água salobra com capacidade de produção de 1,0 m3 h-1 de água tratada, instalado na estação de tratamento de água (ETA) da Sanepar, no balneário de Praia de Leste, no litoral do estado do Paraná. A água salobra foi preparada a partir da mistura da água bruta do Rio das Pombas, manancial que abastece o balneário, e água do mar. As misturas foram realizadas até obter concentrações de 1000 e 1500 ± 100 mg L-1 de sólidos dissolvidos totais (SDT). O sistema foi composto de ultrafiltração como pré-tratamento à osmose reversa. Os experimentos foram realizados durante o período de 15 dias para cada concentração de SDT da água salobra obtendo-se remoções de 99,0 e 99,1%, para 1500 ± 100 mg L-1 e 1000 ± 100 mg L-1, respectivamente. Além dos SDT, foram avaliados outros parâmetros de qualidade da água como: condutividade elétrica, turbidez, cor aparente, alcalinidade, dureza total, cálcio, magnésio, cloretos, sulfatos, pH e temperatura. Durante os experimentos foram avaliados potencial de oxirredução (ORP) e a pressão osmótica, a taxa de filtração e a taxa de recuperação na membrana de osmose reversa. O sistema de ultrafiltração foi mais eficiente na remoção de turbidez e cor aparente, sendo que o sistema de osmose reversa apresentou melhor eficiência na remoção de sólidos dissolvidos totais.

Flavobacterium psychrophilum, the causative agent of bacterial cold water disease (BCWD), is tolerant of recommended ultraviolet (UV) doses used in recirculation aquaculture systems (RAS). Membrane filtration (MF) is used to remove pathogens from wastewater in many industries, but has not been thoroughly tested in RAS. In this study, bacterial removal efficiencies were assessed between MF and UV treatments over 30 days in an RAS. Bacterial removal efficiencies were not significantly different (p > 0.05) between MF and UV treatments, which removed 98.5 ± 0.4 % and 99.6 ± 0.1 % of total bacteria and 93.2 ± 5.2 % and 92.5 ± 4.1 % of heterotrophic bacteria, respectively. Under laboratory conditions, a MF system was challenged with concentrated doses of F. psychrophilum and achieved 5.8 ± 0.2 log reductions of the pathogen. Therefore, MF represents a potential alternative to UV irradiation and could be used to reduce the prevalence of F. psychrophilum in RAS, potentially reducing the incidence of BCWD and its impact on the aquaculture industry. / Environment Canada and Ontario Ministry of Agriculture, Food and Rural Affairs.