81 |
Energy generating performance of domestic wastewater fed sandwich dual-chamber microbial fuel cells26 June 2015 (has links)
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...
|
82 |
Obtenção de ingrediente lacteo enriquecido em lipideos polares a partir de leitelho de soro / Obtention of dairy ingredient enriched in polar lipids from whey buttermilkCosta, Marcela de Rezende 12 September 2008 (has links)
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
|
83 |
EFICIÊNCIA DE UM SISTEMA DE DESSALINIZAÇÃO DE ÁGUA SALOBRA UTILIZANDO ULTRAFILTRAÇÃO E OSMOSE REVERSAAlmeida, Juliano Penteado de 20 April 2017 (has links)
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.
|
84 |
Evaluation of Membrane Filtration and UV Irradiation for the Control of Flavobacterium psychrophilum in Recirculation Aquaculture SystemsHuyben, David C. 07 January 2013 (has links)
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.
|
85 |
Caractérisation In-Situ de dépôts formés en filtration membranaire de suspensions particulaires et de biofluides : intéraction entre structure locale et performances du procédé / In-situ characterization of deposits formed during membrane filtration of particulate suspensions and biofluids : interactions between local structure and process performancesLoulergue, Patrick 09 November 2012 (has links)
Le colmatage membranaire demeure l’un des verrous majeurs des bioréacteurs à membrane (BAM). Ces travaux visent à apporter une contribution à la compréhension de la dynamique de structuration de dépôts complexes formés lors de la filtration frontale de (bio)fluides et son impact sur les performances de filtration. Pour cela, différents outils permettant la mesure in-situ des propriétés structurelles locales des dépôts ont été utilisés de manière à pouvoir relier ces propriétés aux performances globales de filtration. Les propriétés électrocinétiques des dépôts ont également été étudiées. Deux méthodes, l’une optique et l’autre acoustique, ont été utilisées pour caractériser les propriétés structurelles locales des dépôts (épaisseur, cinétique de croissance). Dans un premier temps, les épaisseurs obtenues par les méthodes optiques et acoustiques ont été comparées. Il a été montré que, dans le cas de dépôts peu poreux, les deux méthodes conduisent aux mêmes épaisseurs de dépôts. Dans le cas de dépôts plus poreux, ces deux méthodes permettent l’obtention de données complémentaires à deux niveaux de profondeur différents au sein du dépôt. L’influence des conditions opératoires sur la structuration de dépôts de particules modèles a ensuite été étudiée. Grâce à la méthode optique il a été montré que, quelles que soient les conditions opératoires, il existe une variation temporelle des propriétés du dépôt. De plus, une répartition non homogène du dépôt à la surface de la membrane peut également exister, favorisée par de faibles répulsions entre particules. Enfin, l’applicabilité des différentes méthodes au cas des biofluides issus de BAM a été évaluée. La structure de dépôts complexes constitués lors de la filtration de ces biofluides a ensuite été étudiée. La compressibilité des dépôts, mise en évidence à l’échelle globale par suivi des performances de filtration, a également été observée à l’échelle locale : l’épaisseur du dépôt décroît avec une augmentation de la PTM. De plus, à l’échelle locale, une variabilité spatiale des propriétés du dépôt a été mise en évidence. Afin de contrôler la compressibilité des dépôts l’impact de l’ajout de particules au sein du biofluide a été évalué / Membrane fouling is one of the major drawbacks of membrane bioreactors. This study is thus a contribution to the understanding of the dynamic structuring of complex deposits build-up during dead-end filtration of complex biofluids. Several tools were used to perform in-situ characterization of cake layer structural properties at local scale and to link them to global filtration performances. The electrokinetics properties of the deposit were also investigated. An optical and an acoustic method were used to measure local cake thickness and growth kinetics. The thicknesses given by the two methods were first compared. It was shown that for compact deposits the two different methods lead to the same thickness of the deposit. For more porous deposits, these two methods allow to obtain complementary data at two different depths of the deposits. The influence of operating conditions on cake layer structuring during filtration of modelled particles was evaluated. Using the optical method it was shown that, whatever the operating conditions, the cake structure is not constant in time. Furthermore, a spatial variability of the cake layer thickness might exist especially in the case of weak particle-particle repulsion. Finally, it has been investigated whether the different methods could be applied or not to the case of biofluid filtration. The structural properties of the complex deposits built up during diluted activated sludge filtration were investigated. Cake compressibility was observed at global scale by a monitoring of process performances and was also observed at local scale: cake thickness decreases as TMP increases. Furthermore, at local scale, a spatial variability of deposit structure was found. Particle addition into the biofluid was assessed in order to mitigate compressibility effects
|
86 |
Citometria de fase sólida aplicada ao teste de esterilidade do produto Cloreto de Sódio 0,9% Solução Injetável / Solid-Phase Cytometry applied to sterility test for Sodium chloride 0.9% Injectable Solution ProductSilva, Gisele Badauy Lauria 22 June 2015 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2017-05-05T18:49:22Z
No. of bitstreams: 2
Dissertação - Gisele Badauy Lauria Silva - 2015.pdf: 2934917 bytes, checksum: 7660d0a89305d09f8d7a2fe77bda401e (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-05-10T13:35:58Z (GMT) No. of bitstreams: 2
Dissertação - Gisele Badauy Lauria Silva - 2015.pdf: 2934917 bytes, checksum: 7660d0a89305d09f8d7a2fe77bda401e (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-05-10T13:35:59Z (GMT). No. of bitstreams: 2
Dissertação - Gisele Badauy Lauria Silva - 2015.pdf: 2934917 bytes, checksum: 7660d0a89305d09f8d7a2fe77bda401e (MD5)
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Previous issue date: 2015-06-22 / The sterility test is a test that certificate the absence of viable microorganisms in pharmaceutical raw materials, drugs and medical device. The Solid Phase Cytometry method (SFC) is based on the detection of viable cells through the use of viability markers reagents, that permeate the cell membrane and are cleaved by nonspecific esterase enzymes, forming the fluorochromes that are detected by ChemScan RDI® equipment. It is a fast and innovative method for the sterile injecting drugs area. The objective of the study was to evaluate and validate this technology applied to the sterility test, of the product Sodium Chloride (NaCl) 0.9% Injectable Solution, using the ChemScan RDI® equipment (CS RDI®). Eight microorganisms were evaluated, being six compendial (Clostridium sporogenes NCTC 12935 (ATCC 11437), Pseudomonas aeruginosa NCTC 12924 (ATCC 9027), Staphylococcus aureus NCTC 10788 (ATCC 6538), Bacillus subtilis NCTC 10400 (ATCC 6633), Aspergillus brasiliensis NCPF 2275 (ATCC 16404) and Candida albicans NCPF 3179 (ATCC 10231)) and two "in house” microorganisms, obtained from bioburden monitoring of pre sterilization (Micrococcus luteus and Staphylococcus epidermidis). The Solid Phase Cytometry methodology through logistic regression statistical analysis and Chi-square test, showed to be more rapid than the sterility test by membrane filtration (MF) for all tested microorganisms, reducing the analysis time from 14 days to about 3 hours. The method was validated by the use of qualitative parameters: specificity, limit of detection and robustness. / O teste de esterilidade é um ensaio que certifica a ausência de micro-organismos viáveis em insumos farmacêuticos, medicamentos e produtos para saúde. A Citometria de Fase Sólida (CFS) é um método rápido e inovador para a área de medicamentos estéreis injetáveis e é fundamentado na detecção de células viáveis através da utilização de reagentes marcadores de viabilidade, que permeiam a membrana celular e são clivados por enzimas esterases não específicas, formando o fluorocromo, que são detectados pelo equipamento ChemScan RDI®. O objetivo do estudo foi avaliar e validar esta tecnologia aplicada para o teste de esterilidade, no produto Cloreto de Sódio (NaCl) 0,9% Solução Injetável, utilizando o equipamento ChemScan RDI® (CS RDI®). Os micro-organismos padrões utilizados para os testes foram Clostridium sporogenes NCTC 12935 (ATCC 11437), Pseudomonas aeruginosa NCTC 12924 (ATCC 9027), Staphylococcus aureus NCTC 10788 (ATCC 6538), Bacillus subtilis NCTC 10400 (ATCC 6633), Aspergillus brasiliensis NCPF 2275 (ATCC 16404) e Candida albicans NCPF 3179 (ATCC 10231), e dois micro-organismos “in house” obtidos do monitoramento da biocarga pré esterilização, o Micrococcus luteus e Staphylococcus epidermidis. O método de Citometria de Fase Sólida mostrou-se significativamente mais rápido em relação ao teste de esterilidade por filtração em membrana (FM) para todos os micro-organismos testados, reduzindo o tempo de análise de 14 dias para aproximadamente 3 horas. O método foi validado por meio da utilização dos parâmetros qualitativos: especificidade, limite de detecção e robustez.
|
87 |
Development of Combination Processes Consisting of Ozonation, Coagulation and Ceramic Membrane Filtration for Water Reclamation based on Evaluation of Risk and Energy / リスクおよびエネルギー評価に基づくオゾン、凝集、セラミック膜ろ過による複合水再生処理プロセスの開発に関する研究Wang, Hong Yang 25 March 2013 (has links)
Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第17538号 / 工博第3697号 / 新制||工||1563(附属図書館) / 30304 / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 田中 宏明, 教授 清水 芳久, 教授 伊藤 禎彦 / 学位規則第4条第1項該当
|
88 |
Modélisation de l'hydrodynamique et des transferts dans les procédés de filtration membranaire / Modeling of hydrodynamics and transfer phenomena in cross-flow membrane filtrationBernales chavez, Braulio 10 December 2013 (has links)
L'accumulation du soluté à la surface d'une membrane entraîne le phénomène de polarisation de concentration. Ceci est un problème qui affecte tous les systèmes de filtration membranaire car il a pour effet une augmentation de la pression osmotique et par conséquence une réduction substantielle du flux de perméat. Afin de comprendre ce phénomène, nous avons d'abord mené une étude analytique de la filtration tangentielle en solvant pur prenant en compte de l'influence de la pression motrice locale sur le taux de perméation. Lors de cette étude, des solutions analytiques qui augmentent en précision avec l'ordre développé ont ete dérivées. Ensuite nous avons développé une approche analytique qui couple l'hydrodynamique aux transferts de matière pour le cas d'un système de filtration qui opère sous haute pression avec un taux de récupération faible. Dans le but d'intégrer à la fois la dépendance de la pression transmembranaire locale sur le flux de perméat et l'influence de la polarisation de concentration à travers leurs effets osmotiques sur la pression effective, nous avons développé un modèle numérique qui résout l'équation de conservation du soluté couplée aux équations de Navier-Stokes en régime stationnaire dans l'approximation de Prandtl. Nous avons validé cette approche grâce aux solutions analytiques précédemment dérivées. Ensuite, nous avons testé l'influence des principaux paramètres de fonctionnement sur la performance du système et comparé nos résultats avec ceux d'autres modèles numériques. Finalement, la pertinence du modèle a été quantitativement vérifiée grâce à des données tirées des expériences bien documentées en osmose inverse. / Concentration polarization of solute at the membrane surface, because of osmotic pressure effects, is an important phenomenon that can cause substantial reductions in permeation. To understand these phenomena: we first analyze the filtration process for a pure solvent, imposing the influence of the driving pressure on permeation at the membrane. We obtain accurate analytical solutions for the flow fields. We then derive an analytical solution that coupled hydrodynamics to mass transfer for filtration systems working in a situation of High Pressure and Low Recovery. Second, we develop a numerical model that incorporates both physical aspects: the dependency of pressure on permeation and the influence of concentration polarization and their related osmotic effects in the effective pressure at the membrane. For that, the numerical approach solves the solute conservation equation coupled with the Navier-Stokes equations under the steady Prandtl approximation. The solution of the system is performed using a finite difference method of order 2. The validity of this approach is successfully demonstrated with the previous analytical solutions for hydrodynamics, as well as for the coupling with mass transfer. We then test the influence of the main operating parameters (inlet concentration, axial flow rate, operating pressure and membrane permeability) on the performance of the filtration system and compare the results with other numerical models that takes into account concentration polarization phenomenon. Finally, the validity of this model is quantitatively well-proved when using the reported data resulting from reverse osmosis experiments.
|
89 |
Evaluation of a small scale water disinfection system using WFMFAlfa, Dorcas Enaji January 2017 (has links)
Submitted in fulfillment of the academic requirement for the degree Master of Engineering in Chemical Engineering, Department of Chemical Engineering, Faculty of Engineering and the Built Environment, Durban University of Technology, Durban, South Africa, 2017. / Provision of microbiologically safe drinking water for people living in the rural areas of developing countries remains a major challenge to date. One of the reasons is due to the inability to access potable water mainly because of poor existing water purification systems. Current measures have been put in place to address the challenges of rural water supply. Development of appropriate technologies such as decentralized water treatment supply in the form of point of use (POU) systems are been considered.
In lieu of the above, an appropriate POU system known as the Remote Rural Water Treatment System (RRWTS) was developed at Durban University of Technology (DUT). The RRWTS is polyester based locally sourced Woven Fabric Microfiltration (WFMF) membrane system. The unit is made up of flat sheet modules that are assembled into a pack. It is a robust gravity driven system with the ability to remove suspended solids and colloids in the form of turbidity. The system has high flux of 35 ± 7 LMH and turbidity below 1 NTU, it has the ability to remove pathogens well above 95%. However, this does not comply with WHO and SANS drinking water standards of zero E. coli count/100 ml of treated water. In order to bring the water treated by RRWTS to a satisfactory level for drinking, it is then necessary to add a separate disinfection step like chlorination step to further remove the remaining microbial contaminants.
Thus the main objective of the study was to evaluate the disinfection efficacy of two disinfectants namely waterguard and bromochlor tablet disinfectants and investigate their integration with the WFMF membrane. The study was categorised into three parts. The first part is the addition of disinfectants to unfiltered river water sources for the determination of residual chlorine and the most optimum dose that will yield effective disinfection and also evaluate the extent of E. coli removal by the disinfectants. The second stage was the filtration of four river water sources using the woven fibre membrane (WFM) to determine the efficiency of WFMF. Finally the effect of disinfection kinetics on disinfection was achieved by agitating the water after disinfection and allowing it to stand at different contact times. Performance of the RRWTS was determined by the amount of E. coli and turbidity removed during filtration using WFMF and by chemical disinfectants after filtration.
The results on residual chlorine for different water sources showed that feed quality and disinfectant dose determines the quantity of residual chlorine on all the water sources. The effectiveness of chemical disinfectants in E. coli removal is affected by the quality of water to be disinfected. The study showed that turbidity plays a major role on disinfection by increasing chlorine demand on water sources with high turbidity levels. The WFMF demonstrated excellent filtration performance by producing permeates with turbidity less than 1 NTU for feed turbidities ranging from 10 to 200 NTU. The E. coli removal efficiency by WFMF was very high on all the water sources treated. There was 95-99.8% E. coli removal on raw feeds with influent E. coli ranging between 500 and 44500 CFU/100 ml.
It was seen that major benefits are derived from integrating the WFMF (RRWTS) with chemical disinfection. The benefits includes; better disinfection that meets drinking water set guidelines of zero E. coli and improved quality of water. The need for disinfection kinetics in order to obtain superior disinfection was eliminated. The possibility of disinfection-by-product formation was reduced as smaller quantities of chemical disinfectants were required for complete disinfection on the filtered water. / M
|
90 |
Metodika návrhu systému využití šedých vod ve vybraných objektech / Methodology of use greywater in the selected objectsRaček, Jakub Unknown Date (has links)
The concept of reusing wastewater in buildings has recently become more important. This is due to change in climatic conditions and reduction of the yield of water resources. Greywater can broadly be defined as not extremely polluted wastewater coming from basins, showers, baths, kitchen sinks and washing machines. The concept based on the use of alternative rate sources wouldn't need same strict parameters as drinking water. Dissertation engage in collecting greywater from basins, showers and wash machines separately from the other more polluted domestic wastewater at the dorms, the laundry machines, the hotels, detached houses, the swimming pools, the office buildings and other buildings. The research showed that membrane filtration meets all needed parameters of water quality and can be used in house systems where we use cleansed white water to flush toilets, watering garden or grass areas. There is still a lack of experience and documentation for such system of operation in our country. Systems of use of greywater in selected objects are detaily solved in my dissertation directed at system proposal.
|
Page generated in 0.3748 seconds