Dissertations / Theses on the topic 'Membrance filters'
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Ndinisa, Nkosinathi Vincent Chemical Sciences & Engineering Faculty of Engineering UNSW. "Experimental and CFD simulation investigations into fouling reduction by gas-liquid two-phase flow for submerged flat sheet membranes." Awarded by:University of New South Wales. School of Chemical Sciences and Engineering, 2006. http://handle.unsw.edu.au/1959.4/32872.
Full textSoares, Robson de Miranda. "Membranas suportadas de alumina, obtidas pelo método da sedimentação gravitacional." Universidade de São Paulo, 1998. http://www.teses.usp.br/teses/disponiveis/88/88131/tde-10092008-110844/.
Full textThis work is concerned with ceramic membrane preparation supported on a ceramic substrate having high permeability, high porosity and reasonable mechanical strength. Membranes were prepared from AKP-50 alumina by the gravitational sedimentation method followed by sintering at 1000°C for 0.5 h. Membranes showed a unimodal narrow pore size distribution in the 0.04 to 0.09 range, thickness of 57 μm and 0.4 m3/m2h. flow rate. Substrates were prepared by uniaxial compression, at 33 MPa, of alumina PMMA stearic acid powder composites followed by organic burning and final sintering at 1600°C for 3h. In order to increase alumina APC-SG grain size distribution to 250- 500 μm range, alumina was previously calcined at 1600°C for 1h. Substrates show high mechanical strength, 4.0 to 2 m3/m2h flow rate, 60% porosity and pore size distribution in the range of 10-100 μm and from 0.4 to 2.0 μm. Due to the large difference between the substrate pore diameter and the AKP-50 alumina grain size distribution (d50 = 0.3 μm) used in the membrane preparation, it was necessary to add an intermediary APC-SG layer. This layer was prepared also by the gravitational sedimentation method and sintered at 1500°C for 1h. The intermediary layer/substrate showed 56% porosity, 10 m3/m2h flow rate and a narrow pore sue distribution in the 0.4-2.0 μm range.
Poletto, Patrícia. "Caracterização de membranas de poliamida 66 preparadas pelo método de inversão de fases." reponame:Repositório Institucional da UCS, 2010. https://repositorio.ucs.br/handle/11338/573.
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In the present study, polyamide 66 (PA 66) membranes were prepared by phase inversion (PI) and characterized in order to verify their potential application in separation processes. PA 66 membranes were prepared using two different solvents, formic acid (FA) and chloridric acid (HCl), and water as a non-solvent. Membranes prepared in film form (not supported) were characterized by Fourier-transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC) and the results showed that the chemical structure and thermal behavior of the PA 66 were not altered by the use of acids as solvents. The films revealed an asymmetric structure with a dense top layer and a porous sublayer featuring spherical pores observed by scanning electron microscopy (SEM). The thickness of the dense layer varied from 10 to 25 μm in films prepared with FA and HCl, respectively. The increase in thickness of the dense layer, i.e., the reduction of empty spaces, directly influenced the results regarding water absorption percentage and total porosity. The porosity found was 15% and 50% for films prepared with FA and HCl, respectively. Water vapor flux was lower in films with a thicker dense layer as a result of a greater resistance to mass transfer. In order to increase mechanical resistance in polyamide films, supported membranes with polyester fabric were prepared for latter application in separation processes through high pressure. Supported membranes were characterized by BET techniques for the determination of pore size, reverse osmosis and ultrafiltration assays. Both membranes prepared with FA and HCl showed very similar pore sizes when analyzed by/with BET. A compression assay with pure water performed at a pressure of 40 bar revealed that membranes prepared with FA undergo greater compaction of its structure and had a permeate flux value of approximately 22 Lm-2h-1 whereas the membrane prepared with HCl had a permeate flux value of 312 Lm-2h-1. On reverse osmosis assays, the maximum rejection to sodium chloride was 7% and 4% for FA-3 and HCl-3 membranes, respectively. On ultrafiltration assays, performed at 15 bar, both membranes had rejection values close to 70% for egg albumin and 80% for bovine albumin. Based on this result, it is possible to conclude that both membranes revealed pore size and rejection characteristics for application in ultrafiltration processes.
Bahia, Adilson Silva [UNESP]. "Tratamento de efluente de curtume por biofiltro aerado Submerso pré-tratado com microfiltro de membrana." Universidade Estadual Paulista (UNESP), 2014. http://hdl.handle.net/11449/111149.
Full textOs efluentes do processo de industrialização do couro em curtumes apresentam, além de elevadas concentrações de matéria orgânica em termos de Demanda Química de Oxigênio (DQO) e Demanda Bioquímica de Oxigênio (DBO), altas concentrações de sólidos totais, suspensos e sulfeto, o que torna o tratamento destes efluentes problemático. O objetivo do presente trabalho foi avaliar a biotratabilidade dos efluentes de curtumes por meio do tratamento por Biofiltro Aaerado Submerso (BF) após pré-tratamento por membrana de microfiltração. Os resultados mostraram que pode haver a viabilidade técnica no uso de BF para remoção de matéria orgânica e sulfeto de águas residuárias industriais de curtume, pois atingiram, respectivamente, a remoção 84% e 98 %
The effluents from leather tanning process have in addition to high concentrations of organic matter in terms of Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD), high concentrations of total solids, total suspended solids and sulfide, which makes problematic the treatment of these effluents. The objective of this study was to evaluate the biotreatability of tannery effluent by submerged aerated biofilter after microfiltration membrane pretreatment. The results showed that can be used in the technical feasibility of BF removal of organic sulphide and industrial raw tannery wastewater as it amounted, respectively, removal to 84% and 98%
Bahia, Adilson Silva. "Tratamento de efluente de curtume por biofiltro aerado Submerso pré-tratado com microfiltro de membrana /." Ilha Solteira, 2014. http://hdl.handle.net/11449/111149.
Full textBanca: Liliane Lazzari Albertin
Banca: Luis Fernando Rossi Léo
Resumo: Os efluentes do processo de industrialização do couro em curtumes apresentam, além de elevadas concentrações de matéria orgânica em termos de Demanda Química de Oxigênio (DQO) e Demanda Bioquímica de Oxigênio (DBO), altas concentrações de sólidos totais, suspensos e sulfeto, o que torna o tratamento destes efluentes problemático. O objetivo do presente trabalho foi avaliar a biotratabilidade dos efluentes de curtumes por meio do tratamento por Biofiltro Aaerado Submerso (BF) após pré-tratamento por membrana de microfiltração. Os resultados mostraram que pode haver a viabilidade técnica no uso de BF para remoção de matéria orgânica e sulfeto de águas residuárias industriais de curtume, pois atingiram, respectivamente, a remoção 84% e 98 %
Abstract: The effluents from leather tanning process have in addition to high concentrations of organic matter in terms of Chemical Oxygen Demand (COD) and Biochemical Oxygen Demand (BOD), high concentrations of total solids, total suspended solids and sulfide, which makes problematic the treatment of these effluents. The objective of this study was to evaluate the biotreatability of tannery effluent by submerged aerated biofilter after microfiltration membrane pretreatment. The results showed that can be used in the technical feasibility of BF removal of organic sulphide and industrial raw tannery wastewater as it amounted, respectively, removal to 84% and 98%
Mestre
Nel, A. M. "Removal of organic foulants from capillary ultrafiltration membranes by use of ultrasound." Thesis, Link to the online version, 2006. http://hdl.handle.net/10019/1997.
Full textLi, Hong-yu Graduate School of Biomedical Engineering Faculty of Engineering UNSW. "Mechanism studies for crossflow microfiltration with pulsatile flow." Awarded by:University of New South Wales. Graduate School of Biomedical Engineering, 1995. http://handle.unsw.edu.au/1959.4/17858.
Full textCamargo, Liliane Rodrigues 1981. "Formação de biofilmes microbianos em membranas poliméricas de poliamida e polietersulfona e seu controle por agentes sanitizantes." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/255788.
Full textDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos
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Resumo: O grande consumo de águas minerais tem alavancado muitos estudos de relação caracterização microbiológica, nas mais diversas regiões brasileiras. Trabalhos revelam que a grande maioria das águas brasileiras envasadas e águas de poços artesianos possuem contaminação microbiana, causando grande preocupação com relação à qualidade da água a ser consumida. Dentre os processos para tratamento da água mineral, a fim de atender as exigências comerciais e de legislações, está a microfiltração. O processo consiste da utilização de filtros de membranas poliméricas, nos quais os microrganismos ficam retidos (barreira mecânica). De acordo com a Resolução RDC nº 275/2005 Agência Nacional de Vigilância Sanitária (ANVISA), os microrganismos Escherichia coli e Pseudomonas aeruginosa, estão inseridos, juntamente com outras bactérias, como Enterococos, Clostridium perfringens e coliformes totais no quadro de controle microbiano de águas minerais. Devido à utilização dos filtros de membrana para controle destes microrganismos, há a necessidade da realização da sanitização desses filtros para evitar proliferação de microrganismos na superfície; prevenindo o entupimento dos poros da membrana e contaminação do processo. O sanitizante a base de ácido peracético e água quente são os principais agentes sanitizantes utilizados na indústria de água mineral para sanitização de equipamentos. Assim este trabalho objetivou avaliar a formação de biofilme microbiano de Escherichia coli e Pseudomonas aeruginosa em membranas poliméricas de poliamida e polietersulfona e a eficiência da sanitização das membranas por solução de ácido peracético a 0,1%, 0,2% e água quente a 85 ºC em dois diferentes tempos de contato, 10 minutos e 20 minutos. O teste foi realizado através do contato de cupons de 1 cm2 das membranas com o inóculo na concentração de 104 UFC/ mL, em temperaturas de 5, 25 e 35ºC e a análise dos cupons após 24h, 48h e 72h de contato. A quantidade de células aderidas de Escherichia coli para ambas as membranas foi de 4 log UFC/ cm2 para as primeiras 24h de contato, chegando até 6 log UFC/cm2 após 72h de contato para a temperatura de 35ºC. Para Pseudomonas aeruginosa, o comportamento de adesão foi similar, onde a maior quantidade chegou à 6,25 log UFC/cm2 após 72h de contato para a temperatura de 25ºC. Para avaliar a eficiência dos agentes sanitizantes, os cupons foram submetidos ao processo de adesão dos microrganismos e após 24 horas de contato na temperatura de 35ºC foram colocados em contato com a solução sanitizante à base de ácido peracético 0,1%, 0,2% e água quente à 85ºC durante 10 e 20 minutos. Os sanitizantes utilizados ofereceram grande eficiência na redução das bactérias aderidas nas membranas. A concentração do sanitizante químico mais efetivo foi 0,2% para 10 e 20 minutos de contato, onde cerca de 80% dos cupons tiveram redução de > 4 Log UFC/cm2. A água na temperatura de 85ºC em ambos os tempos de contato (10 minutos e 20 minutos) também ofereceu grande eficiência na redução logarítmica dos microrganismos, onde 100% dos cupons apresentaram redução > 4 Log UFC/cm2
Abstract: The high consumption of mineral water has leveraged many studies regarding microbiological, in several brazilian regions. Papers reveal that the vast majority of brazilian bottled waters and water from artesian wells have microbiological contamination, causing great concern about the quality of water being consumed. Among the processes for treatment of mineral water in order to meet business requirements and laws is microfiltration. The process consist in the use of polymer membrane filters, the where the microorganisms are withheld (mechanical barrier). According to Resolution RDC 275/2005 of National Agency for Sanitary Vigilance (ANVISA) microorganisms Escherichia coli and Pseudomonas aeruginosa, are inserted, along with other bacteria such as Enterococcus, Clostridium perfringens and total coliforms under control of microbiological characteristics of mineral waters. Due to the use of membrane filters to control these microorganisms, there is the need to perform sanitization filters to prevent the proliferation of microorganisms on the surface, preventing the clogging of the pores of the membrane and process contamination. The sanitizing the basis of peracetic acid and hot water are the main agents sanitizers available in the industry of mineral water to equipments sanitize. This study aimed to evaluate the microbial biofilm formation of Escherichia coli and Pseudomonas aeruginosa in polymeric membranes of polyamide and polyethersulfone membranes and the sanitizing ef ficiencyprocess with of peracetic acid 0.1%, 0.2% and hot water at 85 °C in two different contact times, 10 minutes and 20 minutes. The test was conducted through the contact of coupons with 1 cm2 of the membranes in the inoculum with concentration of 104 CFU /mL, at temperatures of 5, 25 and 35 °C and an alysis of the coupons after 24h, 48h and 72h of contact. The amount of Escherichia coli cells attached to both membranes was 4 log CFU /cm2 for the first 24 hours of contact, reaching 6 log CFU /cm2 after 72 hours of contact to a temperature of 35 °C. For Pseudomonas aeruginosa, the adherence behavior was similar, where the largest amount reached 6.25 log CFU /cm2 after contact for 72 hours at 25 º C. To evaluate the effectiveness of sanitizing agents, the coupons were subjected to the adhesion of microorganisms and after 24 hours of contact at 35 ºC were placed in contact with the sanitizing solution based on peracetic acid 0.1%, 0.2% and hot water at 85 °C for 10 to 20 minutes. The sanitizers used offered high efficiency in reducing bacteria attached on the membranes. The concentration of chemical sanitizer most effective was 0.2% for 10 and 20 minutes of contact, where about 80% of the coupons was reduced by > 4 Log CFU/cm2. The water temperature at 85 °C in both contact times (10 and 20 minutes) also offered greater efficiency in logarithmic reduction of microorganisms, where 100% of the coupons showed a reduction > 4 Log UFC/cm2
Mestrado
Mestre em Tecnologia de Alimentos
Deng, Shi. "Development of a coarse pore membrane bioreactor with in-situ membrane cleaning /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?EVNG%202007%20DENG.
Full textWong, Hiu Man. "Removal of pathogens by membrane bioreactor : removal efficiency, mechanisms and influencing factors /." View abstract or full-text, 2004. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202004%20WONGH.
Full textIncludes bibliographical references (leaves 93-102). Also available in electronic version. Access restricted to campus users.
Biron, Dionisio da Silva. "Preparação e caracterização de membranas impregnadas com nanopartículas de prata e cobre e sua aplicação na desinfecção da água." reponame:Repositório Institucional da UCS, 2016. https://repositorio.ucs.br/handle/11338/1181.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES
Borkar, Neha. "Characterization of microporous membrane filters using scattering techniques." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1289943937.
Full textPang, Shing Kin. "Development of a low-cost membrane with used non-woven material for wastewater treatment /." View abstract or full-text, 2006. http://library.ust.hk/cgi/db/thesis.pl?CIVL%202006%20PANG.
Full textParameshwaran, Kathiravelu Chemical Sciences & Engineering Faculty of Engineering UNSW. "Enhancing membrane processes for water reuse." Awarded by:University of New South Wales. Chemical Sciences & Engineering, 2008. http://handle.unsw.edu.au/1959.4/41495.
Full textLi, Jianxin. "Real-time investigation of fouling phenomena in membrane filtrations by a non-invasive ultrasonic technique." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/53027.
Full textSome digitised pages may appear illegible due to the condition of the original hard copy.
ENGLISH ABSTRACT: Membrane fouling is universally accepted as one of the most critical problems limiting the wider application of membranes in liquid separations. The development and utilization of a suitable non-invasive technique for the on-line monitoring of fouling in industrial and laboratory applications may enable the effectiveness of fouling remediation and cleaning strategies to be quantified. The overall objective of this research is to develop ultrasonic time-domain reflectometry (UTDR) and its use as an analytical tool for the real-time study of inorganic-, organic- and protein- fouling of various types of membranes including nylon, polysulfone (PSU) and polyethersulfone (PESU) and modules, including flatsheet and tubular types. Different separation systems including microfiltration (MF) and ultrafiltration (UF), flat-sheet and tubular modules, and suitable ultrasonic probes were used in this study. Results of this study show a good correlation between the UTDR signal response and the development of a fouling layer on a membrane surface. UTDR effectively detected the appearance, growth and movement of a fouling layer echo as fouling proceeded. Cake (fouling)-layer compressibility was observed by UTDR. The structure and compaction of an asymmetric PSU membrane could be detected by UTDR. UTDR was also successfully used for monitoring membrane cleaning and evaluating the cleaning effectiveness o f various cleaning methods. UTDR results corroborated the flux measurements and SEM analyses. The ultrasonic unit is a programmed microprocessor, and can be used to compare reference and test signals to produce a differential signal (a fouling layer echo). A differential signal indicates the state and progress o f a fouling layer on the membrane surface in actual operations. Both amplitude and arrival time of differential signals as a function of operation time provide useful quantitative information, i.e. changes in thickness and density of a fouling layer, on the fouling processes. A predictive modelling program, ultrasonic reflection modelling (URM), was developed to describe the processes of ultrasonic testing related to the deposition of fouling layers on membrane surfaces. The mathematical model could substantiate changes in the densities of the fouling layer as well as the thickness. This is important as deposit resistance to flow is related to both thickness and density (compressibility). The predicted results of cake layer deposition are in good agreement with the actual UTDR measurements obtained in MF and UF. Furthermore, protein fouling was successfully detected in tubular UF by UTDR. Ultrasonic frequency spectra could be used as an additional tool for fouling detection.
AFRIKAANSE OPSOMMING: Membraan-aanvuiling of -verstopping is die grootste struikelblok wat die meer algemene aanwending van membrane vir verskillende watersuiweringsprosesse beinvloed. Die ontwikkeling en gebruik van ‘n geskikte nie-inmengende tegniek vir die in-lyn meting van aanvuiling van membrane in laboratorium-en nywerheidstoepassings mag ‘n geleentheid bied vir die kwantifisering van die verwydering van aanvuiling en skoonmaakstrategiee. Die hoofdoel van hierdie studie was die ontwikkeling van ultrasoniese tydgebiedsweerkaatsing (Eng: ultrasonic time-domain reflectometry, UTDR) en die gebruik daarvan as ‘n analitiese metode vir die studie van anorganiese-, organiese- en bio-besoedeling op verskeie tips membrane, insluitend nylon, polisufoon (PSU) en polietersulfoon (PESU), in beide platvel- en buismodules. Verskeie skeidingsisteme, insluitend mikrofiltrasie (MF) en ultrafiltrasie (UF) is ontwerp en gebruik in hierdie studie. Eksperimentele resultate het goeie ooreenstemming tussen die UTDR seinrespons en die ontwikkeling van ‘n aanvuilingslaag op die membraanoppervlakte bewys. Die ultrasoniese tegniek kon die vorming, groei en beweging van ‘n bevuilingslaagterugkaartsing waarneem namate bevuiling vorder. Aanvuilingslaagsamepersing is deur UTDR waargeneem. Die struktuur en samepersing van ‘n asimmetriese PSU membraan is ook deur UTDR gesien. UTDR is verder suksesvol gebruik om die skoonmaak van membrane te monitor en om die skoonmaakgeskiktheid (cleaning effectiveness) van verskeie skoonmaakmetodes te bepaal. UTDR resultate het permeaatvloeimetings en SEM analyses bevestig. Die ultrasoniese eenheid is ‘n geprogrameerde mikroverwerker, en kan gebruik word om verwysings- en toetsseine te vergelyk, en dan ‘n differensiaalsein te gee (‘n aanvuilingslaagweerklank). ‘n Differensiaalsein dui die toestand en vordering van ‘n aanvuilingslaag op die membraanoppervlakte gedurende gebruik aan. Beide amplitude asook aankomstyd van differensiaalseine as funksies van gebruikstyd verskaf bruikbare kwantatiewe inligting, dws. Veranderings in die dikte en digtheid van ‘n aanvuilingslaag, op die aanvuilingsproses. ‘n Voorspellingsmodelleringprogram - ultrasonieseweerkaatsingsmodellering (Eng: ultrasonic reflection modeling, URM) is ontwikkel om die proses van ultrasoniese toetsing by die deponering van aanvuilingslae op membraanoppervlaktes beter te beskryf. Veranderings in die digtheid en dikte van die aanvuilingslaag teenvloei is verwant aan dikte en digtheid (saampersbaarheid). Die voorspelde resultate van aanvuilingslaagdeponering stem goed ooreen met die werklike UTDR-metings wat in MF en UF gemaak is. Bio-aanvuiling is suksesvol waargeneem deur UTDR in buisvormige UF membrane. Ultrasoniese frekwensiespektra kan dus as ‘n bykomende metode gebruik word vir die waarneming van aanvuiling op skeidingsmembrane.
Melamane, Xolisa. "Cleaning of fouled membranes using enzymes from a sulphidogenic bioreactor." Thesis, Rhodes University, 2004. http://hdl.handle.net/10962/d1015764.
Full textYe, Yun School of Chemical Engineering & Industrial Chemistry UNSW. "Macromolecular fouling during membrane filtration of complex fluids." Awarded by:University of New South Wales. School of Chemical Engineering and Industrial Chemistry, 2005. http://handle.unsw.edu.au/1959.4/33245.
Full textTurkson, Abraham K. "Electro-ultrafiltration with rotating dynamic membranes." Thesis, McGill University, 1985. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=72036.
Full textFour dynamic membranes, Zr(IV) oxide, calcium oleate, poly-2-vinylpyridine and cadmium sulfide, were used to filter bovine serum albumin (BSA) in a disodium phosphate solution at pH = 8 and Prussian blue in distilled water. Prussian blue is a particle of 0.01(mu)m diameter with a zeta potential of -41mV while BSA is a macromolecule of 69,000 molecular weight, a Stokes-Einstein radius of 0.0038(mu)m and a zeta potential of -23.3mV at pH = 8. For BSA, the flux declined with time while the rejection increased. Filtrate fluxes increased with rotation rate and electric field and declined with concentration for both feeds. The flux declined beyond N = 2000rpm and was constant above C(,0) = 5.0wt%. For Prussian blue, the rejection was greater than 90% at all levels of E, N and C(,0). For BSA, the rejection increased with rotation rate and declined with concentration. The BSA rejection declined above N = 2000rpm and was constant beyond C(,0) = 0.5wt%.
A mathematical model was derived to predict the time variation of filtrate flux and a rejection model was used to predict the effect of surface concentration on BSA rejection.
Yu, Di. "Inorganic mesoporous membrane for water purification applications synthesis, testing and modeling /." Columbus, Ohio : Ohio State University, 2006. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1162323090.
Full textLodge, Benjamin Nicholas. "Membrane fouling during domestic water recycling." Thesis, Cranfield University, 2003. http://dspace.lib.cranfield.ac.uk/handle/1826/11067.
Full textMaskan, Fazilet Chemical Engineering & Industrial Chemistry UNSW. "Optimization of reverse osmosis membrane networks." Awarded by:University of New South Wales. Chemical Engineering and Industrial Chemistry, 2000. http://handle.unsw.edu.au/1959.4/18790.
Full textNipprasch, Dirk. "Zeolithische Filter und Membranen in der Gassensorik." [S.l. : s.n.], 2002. http://www.gbv.de/dms/ilmenau/toc/356752046.PDF.
Full textGregg, Andrea. "The application of nanofibrous membranes with antimicrobial agents as filters." Kansas State University, 2010. http://hdl.handle.net/2097/6822.
Full textDepartment of Architectural Engineering and Construction Science
Julia A. Keen
Nanofibers are classified as fibers less than 1 micrometer in diameter. These fibers can be layered to form nanofibrous membranes, and these membranes offer great potential in the filtration industry. The membranes' smaller fiber diameters and pore sizes permit such filters to filter out more and smaller particulate. Additionally, antimicrobial agents can be incorporated into the membrane to inhibit fungal and bacterial growth on the membrane’s surface. This report evaluates nanofibrous membranes with antimicrobial agents and their potential in two specific locations: cleanrooms and protective environment rooms, where bacterial and fungal growth would have a detrimental effect on the process or occupant of the space.
Wang, Li. "Internal surface coating and photochemical modification of polypropylene microfiltration membrane." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ30119.pdf.
Full textRamli, Nor Hanuni. "Ultrafiltration of polydisperse colloidal silica." Thesis, Swansea University, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.678552.
Full textHamann, Martin Louis. "System hydrodynamics to reduce fouling of air-sparged immersed flat-sheet microfiltration membranes." Thesis, Stellenbosch : University of Stellenbosch, 2010. http://hdl.handle.net/10019.1/5206.
Full textENGLISH ABSTRACT: Immersed membrane systems hold many operational and environmental advantages in biological treatment of wastewater. However, immersed membrane filtration have only found application in niche markets to date because of higher capital and operating costs associated with membrane fouling. But with capital costs on the decline as membranes become less expensive, immersed membrane systems are increasingly considered as an attractive alternative to conventional treatment processes. Operating costs remain high however, since energy intensive techniques such as air-sparging are required to limit membrane fouling. Improving the air-scouring efficiency of air-sparged immersed membranes can significantly reduce operating costs and unlock the immersed membrane system technology to wider application. The aim of this study was to identify factors that will improve air-scouring efficiency in order to produce guidelines that will help in the development of an immersed microfiltration membrane system with a resulting lower operating cost. Although, the research was done on a flat-sheet microfiltration membrane, the guidelines obtained can be used for the development of any immersed microfiltration membrane arrangement. An airlift reactor set-up was chosen for this study. Six system hydrodynamic factors were evaluated in a factorial design to determine their effects on the cross-flow velocity profile. They were the downcomer area to riser area ratio, top clearance distance, bottom clearance distance, aeration intensity, water depth and air sparger location. It was found that the air-scouring efficiency was increased by generating a cross-flow velocity profile with increased magnitude and uniformity, but absolute uniformity of the cross-flow velocity profile was found to be a prerequisite for optimisation of air-scouring efficiency. Downcomer area to riser area ratio was found to be 99.9% significant in determining the magnitude of the cross-flow velocity profile. Two models were developed to respectively predict the relative magnitude and uniformity of the cross-flow velocity profile. By using these two models, a methodology was developed to design an airlift reactor set-up that would produce system hydrodynamics with an improved air-scouring efficiency.
AFRIKAANSE OPSOMMING: Gesonke membraanstelsels beskik oor talle bedryfs- en omgewingsvoordele in biologiese behandeling van afvalwater. Maar weens die hoër kapitaal- en bedryfskostes wat gepaardgaan met membraanbevuiling, kon gesonke membraanstelsels tot op hede nog net toepassing in nismarkte vind. Maar soos kapitaalkoste daal met al hoe goedkoper membrane beskikbaar, word gesonke membraanstelsels al hoe aanlokliker as ‘n alternatief vir konvensionele behandelingsprosesse. Bedryfskostes bly egter hoog aangesien energie-intensiewe tegnieke soos lugborreling benodig word om membraanbevuiling te vertraag. Deur die effektiwiteit van die skropaksie wat lugborreling aan gesonke membrane bied te verbeter, kan ‘n beduidende besparing in bedryfskostes teweeggebring word om sodoende die uitgebreide toepassing van gesonke membraanstelsel tegnologie moontlik te maak. Hierdie studie het ten doel gehad die identifisering van faktore wat lugskropaksie effektiwiteit kan verbeter en om riglyne op te stel vir die ontwikkeling van ‘n gesonke mikrofiltrasie membraanstelsel met gevolglik laer bedryfskostes. Alhoewel hierdie navorsing ‘n plat-blad mikrofiltrasie membraan gebruik het, kan die riglyne steeds vir enige gesonke mikrofiltrasie membraanuitleg gebruik word. Daar is besluit op ‘n lugligter-reaktor opstelling vir hierdie studie. Ses stelselhidrodinamika faktore is geëvalueer in ‘n faktoriale ontwerp om hul effekte op die kruisvloei snelheidsprofiel te bepaal. Hulle was die afvloei-area tot opvloei-area verhouding, topruimte-afstand, bodemruimte-afstand, belugtingsintensiteit, waterdiepte en belugterligging. Daar is bevind dat die lugskropaksie effektiwiteit verhoog word wanneer ‘n kruisvloei snelheidsprofiel geskep word met ‘n verhoogde grootte en gelykvormigheid, maar die absolute gelykvormigheid van die kruisvloei snelheidsprofiel is gevind om ‘n voorvereiste te wees vir optimale effektiwiteit. Afvloei-area tot opvloei-area verhouding is gevind om 99.9% beduidend te wees in die bepaling van die snelheidsprofiel se grootte. Twee modelle is ontwikkel om afsonderlik die relatiewe grootte en gelykvormigheid van die kruisvloei snelheidsprofiel te voorspel. Die modelle is in ‘n metodologie vervat vir die ontwerp van ‘n lugligter opstelling met stelselhidrodinamika wat verbeterde lugskropaksie effektiwiteit sal skep.
Zhou, Fangbin. "Novel Pervaporation for Separating Acetic Acid and Water Mixtures Using Hollow Fiber Membranes." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/7154.
Full textPeterson, Emily Cassidy. "Shear-induced microstructure in hollow fiber membrane dopes." Diss., Georgia Institute of Technology, 2013. http://hdl.handle.net/1853/50245.
Full textFeitosa, Natália dos Reis. "Desempenho de meios filtrantes na remoção de partículas nanométricas de aerossóis." Universidade Federal de São Carlos, 2009. https://repositorio.ufscar.br/handle/ufscar/4021.
Full textUniversidade Federal de Sao Carlos
The interest of studies on the development of techniques for removal of particles in the nanosized scale was promoted by concern about air quality and human health, in addition to restrictions on the control of ultrafine particles, wich are more intransigent by environmental laws. Additionally, the increasing application of nanoparticles in various areas of science and technology has stimulated the development of studies on the subject. Amongst the several equipments capable to operate with efficiency on the particle removal, the fibrous filters are distinguished. Such filters are, in principle, capable to act in sub-micrometer scale, but there is little information about its performance in the nano-sized scale. In this work the performance of a polyester filter, of a HEPA cellulose filter, of a quartz microfiber filter and also of cylindrical filtering membrane, provided by Pam-Membranas Seletivas Ltda, were evaluated. The experimental system was able to simulate a contamination of nanometric particles in a stream of ultrapure air, with the aim of investigating the efficiency of filter media in the removal of nanoparticles. The test aerosol was constituted by NaCl polydisperse nanoparticles, ranging from 6.15 to 245.1 nm. The performance of the filter was evaluated through the analysis of the efficiency of removal of nanoparticles, for the counting of particles before and after to cross the filtering media, using the electric mobility technique. This procedure was performed using the TSI Scannig Mobility Particle Sizer (SMPS), model 3936, which provides the particles concentration, in size range. The results, in general, have showed that the filter media loses efficiency with the increasing filtration velocity and increasing particle size, in the ranged studied, indicating the typical behavior of difusional mechanism. The filtering membranes have showed better performance in the removal of particles unlike the others filters analysed there was no tendency to increase the penetration of particles with increasing the velocity of filtration or particle diameter.
O interesse de estudos acerca do desenvolvimento de técnicas de remoção de materiais particulados na escala nanométrica foi impulsionado pela preocupação com a qualidade do ar e da saúde humana, somada às restrições do controle de particulados ultrafinos, cada vez mais intolerantes pelas leis ambientais. Adicionalmente, a crescente aplicação de partículas nanométricas em diversas áreas da ciência e tecnologia estimulou o aprofundamento de estudos sobre o assunto. Dentre os vários equipamentos capazes de operar com eficiência na remoção de partículas ultrafinas, destacam-se os filtros fibrosos. Tais filtros são, em princípio, capazes de atuar em escala submicrométrica, mas as informações referentes ao seu desempenho em escala nanométrica ainda são pouco conhecidas. No presente trabalho avaliou-se o desempenho de filtros de poliéster, de celulose HEPA, de microfibras de quartzo e, também, de membranas filtrantes cilíndricas, fornecidas pela empresa Pam-Membranas Seletivas Ltda. O sistema experimental disponível era capaz de simular uma contaminação de partículas nanométricas em uma corrente de ar ultrapuro, a fim de que, posteriormente, fosse possível investigar a eficiência dos meios filtrantes na operação de remoção das mesmas. O aerossol de teste era constituído por nanopartículas polidispersas de NaCl, produzidas na faixa de diâmetros de 6,15 a 245,1 nm. O desempenho do filtro foi avaliado através da análise da eficiência de remoção das partículas nanométricas, pela contagem das partículas antes e após a passagem pelo meio filtrante, utilizando a técnica de mobilidade elétrica. Tal procedimento foi realizado por meio de um equipamento da TSI, o Scannig Mobility Particle Sizer (SMPS), modelo 3936, que fornece o número de partículas por faixa de tamanho. Os resultados, em geral, mostraram que a eficiência dos meios filtrantes diminui com o aumento da velocidade de filtração e com aumento do diâmetro, na faixa em estudo, indicando o comportamento típico do mecanismo difusional. As membranas apresentaram um melhor desempenho na remoção das partículas, visto que, diferentemente dos demais meios filtrantes analisados, não se observou tendência para o aumento da penetração de partículas, com o aumento da velocidade de filtração ou diâmetros das partículas, sendo que, em relação à faixa de tamanho, a penetração ocorreu de forma aleatória.
Van, Duyne Scott A. "Digital filter applications to modeling wave propagation in springs, strings, membranes and acoustical space /." May be available electronically:, 2007. http://proquest.umi.com/login?COPT=REJTPTU1MTUmSU5UPTAmVkVSPTI=&clientId=12498.
Full textMalherbe, Gideon Francois. "Development and application of ultrafiltration and reverse osmosis membranes." Thesis, Cape Technikon, 1993. http://hdl.handle.net/20.500.11838/908.
Full textVarious experimental and established membranes were tested on industrial effluents. Ultrafiltration, reverse osmosis and nanofiltration membranes were used in various applications. Research was done on aspects such as the cleaning of fouled membranes, production quality control and process development. Polyvinyl alcohol ultra-thin-film reverse osmosis membranes were manufactured for the desalination of brackish water to a potable standard. The membranes were manufactured in the tubular configuration. Experimental ultrafiltration, reverse osmosis and nanofiltration membranes were tested on cooling water blowdown on a laboratory-scale. On-site testing was done directly on the effluent at a later stage. A s!udy was also conducted to determine the effect of gel-polarization on membrane performance. The gel-layer model was used to predict the limiting flux of specific membranes. Membrane processes were also applied in the fractionation of wine-lees to provide usable by-products such as yeast cells and potassium bitartrate. Ultrafiltration membranes operated in diafiltration mode were used to "wash" the slurry at different solid concentrations. The bitartrate-rich permeate collected from ultrafiltration was then concentrated using reverse osmosis and nanofiltration to allow subsequent precipitation of the product.
Gregory, Sean. "Development of instrumentation for the investigation of surface regeneration for candle filters." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=2238.
Full textTitle from document title page. Document formatted into pages; contains xii, 102 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 80-81).
Nakanishi, Simone Coelho. "Utilização dos componentes lignocelulósicos do bagaço de cana-de-açúcar para produção de membranas." Universidade de São Paulo, 2010. http://www.teses.usp.br/teses/disponiveis/97/97131/tde-20082013-102435/.
Full textThinking of a better use for the surplus of sugarcane bagasse, this study aims to obtain membranes of cellulose acetate composite with oxidized lignins, both isolated from sugarcane bagasse. To this purpose, the macromolecular components of bagasse were separated by applying a steam explosion pre-treatment for removal of hemicellulose and a treatment with sodium hydroxide to separate the lignin and obtaining of crude cellulose pulp. This pulp was bleached and acetylated, and subsequently cellulose acetate membranes were synthesized incorporating oxidized lignin in these membranes in order to increase the metal retention capacity of them. Thus, we intend to obtain a product with higher commercial value, which has applications in water and effluent treatment, which can further contribute to the maintenance of the environment. The membranes were synthesized by phase inversion, using two different methods: I. evaporation-precipitation and II. immersion in coagulation bath. The acetylated material was analyzed by FTIR, confirming the acetylation by the appearance of bands characteristic of acetate and analyzed for degree of substitution, featuring a diacetate. The membranes synthesized by method I were analyzed by SEM, verifying dense structure for the membranes in all compositions, and more rigid than a membrane prepared from a commercial triacetate, according to the data of dynamic mechanical analysis. Tests about permeability and copper retention also were done. Although rigid, they resisted to pressures up to 20 bar. The membrane added with lignin oxidized by laccase showed the best performance in this test, reaching higher flow requiring less pressure. In the test of copper retention, they showed an average retention capacity of 15%, corresponding to 50.5 mg Cu2+/ g lignin. The membranes synthesized by method II were analyzed by SEM, noting differences in morphology when the lignin is added dissolved in NaOH. Thermal analysis showed the Tg of the material near 80 °C, besides showing a higher thermal stability of the material added with oxidized lignin compared to material without lignin and with original lignin. In the permeability test, held at constant pressure of 10 bar, the membrane synthesized with only cellulose acetate cane bagasse showed no flow. The membranes added with original lignin and oxidized lignin showed flow of 3.5 and 6.1 L/h.m2, respectively. The fact was attributed to the morphology of the membranes, since the two latter, which showed flow, have porous structure, while the other has a dense structure. In the test of copper retention, it was possible to visualize the effect of the addition of lignin in the membrane, which increases 3.5 times the cupper retention capacity and, the effect of lignin oxidation, with increases in more 50% this retention capacity in comparison to the addition of the lignin in the original form. However, the results indicate that the synthesized membranes, mainly membranes added with oxidized lignin, are promising for the proposed objective.
Mbanjwa, Mesuli Bonani. "Ultrasonic measurement of membrane fouling during microfiltration of natural brown water." Thesis, Cape Peninsula University of Technology, 2007. http://hdl.handle.net/20.500.11838/890.
Full textThe removal of the colour-eausing natural organic matter (NOM) from natural brown water (NSW) to be used for drinking purposes is of paramount importance. One of the methods available to remove NOM from NSW is the use of pressure-driven membrane separation systems. One of the limitations in efficiently applying membrane filtration in the treatment of NOM-eontaining water is membrane fouling that is caused by foulants, such as NOM, that accumulate on the membrane surface and in the membrane pores. Microfiltration (MF), as a membrane separation system, is susceptible to severe membrane fouling during membrane filtration of NSW. Fouling is characterized by a rapid decline in permeate flux and loss of productivity. Progress in developing more effective control and prevention of fouling is impeded by the absence of suitable fouling measurement and characterization techniques. An in situ method for measuring membrane fouling is necessary for detection of membrane fouling during MF of NSW at the eartiest stages so that the corrective actions can be taken before fouling is permanently adsorbed onto the membrane surface. In this study, an ultrasonic-based method was effectively used to detect and measure the growth of membrane fouling dUring MF of NSW, in situ. Fouling exp~riments results showed the formation of a new peak on the ultrasonic response echo signal due to the presence of a fouling layer on the surface of the membrane. The ultrasonic signals acquired during the in-situ detection of membrane fouling were analysed using wavelet transforms (WTs). Wavelet analysis was applied to differential signals to obtain additional information about fouling. Differential signals were calculated by subtracting the baseline measurement signals from the test signals. The presence of the fouling layer on membranes was verified by atomic force microscopy (AFM) and scanning electron microscopy (SEM) analyses of the fouled membranes.
Michaels, W. C. "Microheterogeneous solid polymer electrolyte (SPE) membranes for electrocatalysis." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52934.
Full textENGLISH ABSTRACT: The deposition of platinum catalyst on cation-exchange membranes was achieved by a counter diffusion deposition method known as the Takenaka- Torikai method. The morphology of the platinum catalyst on the membranes were controlled by varying the conditions of the platinum deposition process, such as, temperature, type of reducing agent and concentration of the platinic acid solution. The effect of the sonication of platinic acid solution and the pre-treatment of membranes on the morphology of a platinum catalyst was also investigated. Platinum loading on cation-exchange membranes was determined by UV spectrophotometric and gravimetric analyses. Suitable conditions for the quantitative determination of the platinum loading on membranes by UV spectrophotometric analysis was established through the development of a protocol. Membranes were characterised using different techniques such as, Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), Infrared spectrometry (IR), Dielectric analysis (DEA) and Brunauer Emmett Teller adsorption (BET). The roughness profile of a platinum catalyst embedded on a membrane was explored by various statistical methods. The statistical analysis of various data sets for a surface of a platinum-containing membrane was investigated using the Hurst exponent. The effect of surface modification of membranes on the deposition process, as well as the morphology of the platinum catalyst, was investigated. Membranes were modified with ethylene diamine (EDA) and cetyltrimethylammonium bromide surfactant. Modification of membranes with cetyltrimethylammonium bromide surfactant resulted in a unique textured platinum catalyst. The electrochemical "switching" phenomenon was investigated for EDAmodified membranes and EDA-modified membranes embedded with platinum catalyst. The "switching" phenomenon was observed in i-V cyclic curves, which were obtained by galvanodynamie measurements. The application of electro catalytic membrane systems in the anodic oxidation of water was investigated by electrochemical techniques such as galvanostatic and cyclic voltammetric measurements.
AFRIKAANSE OPSOMMING: Die deponering van 'n platinum katalis op katioon-uitruil membrane is suksesvol gedoen d.m.v. die Takenaka-Torikai metode. Die morfologie van die platinum katalis op die membrane is gekontrolleer deur variasie van die kondisies van die platinum deponeringsproses, bv. temperatuur, tipe reduseermiddel gebruik en konsentrasie van die platiensuuroplossing, asook die ultrasonifikasie van die platiensuuroplossing en voorafbehandeling van die membrane. UV spektrofotometriese asook gravimetriese analitiese metodes is gebruik om die platinumlading op katioon-uitruil membrane te bepaal. Geskikte kondisies vir die kwantitatiewe bepaling van die platinumlading op membrane d.m.v. UV spektrofotometriese analise is ontwikkel deur die skep van 'n protokol. Membrane is gekarakteriseer d.m.v. die volgende tegnieke: Atoomkrag Mikroskopie, Skanderingselektron Mikroskopie, Infrarooi Spektrometrie, di-elektriese analise en Brunauer Emmett Teller adsorpsie. Die skurtheidsprofiel van 'n platinum katalis op 'n membraan is ondersoek deur gebruik te maak van verskeie statistiese metodes. Statistiese analises van verskeie data stelsels van 'n platinum-bevattende membraan is ondersoek deur gebruik te maak van die Hurst eksponent. \ Die effek van oppervlakmodifikasie op membrane sowel as die deponeringsproses en morfologie van die platinum katalis is ondersoek deur die modifikasie van membrane met etileen diamien (EDA) en setieltrimetielammonium bromied as versepingsmiddel Die elektrochemiese omswaai van EDA-gemodifiseerde membrane sowel as gemodifiseerde platinum bevattende membrane is ondersoek d.m.v. galvanodinamiese metings. Die gebruik van elektro-katalitiese membraansisteme in die anodiese oksidasie van water is ondersoek deur gebruik te maak van elektrochemiese tegnieke, bv. galvanostatiese en sikliese voltammetriese metings.
Neal, Peter Ross Chemical Sciences & Engineering Faculty of Engineering UNSW. "An examination of the nature of critical flux and membrane fouling by direct observation." Awarded by:University of New South Wales. School of Chemical Sciences and Engineering, 2006. http://handle.unsw.edu.au/1959.4/30584.
Full textTumuluri, Uma. "Nonlinear State Estimation in Polymer Electrolyte Membrane Fuel Cells." Cleveland State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=csu1231961499.
Full textZappulla, Antonino. "Filtrazione tangenziale con membrane ceramiche statiche e dinamiche." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/15665/.
Full textSilva, Denilton da. "Estudo da recuperação de lignossulfonatos de baixa massa molar por nanofiltração." [s.n.], 2007. http://repositorio.unicamp.br/jspui/handle/REPOSIP/266200.
Full textTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: Na indústria de papel e celulose os processos de separação por membranas, como a ultrafiltração (UF) e a nanofiltração (NF), são utilizados para a recuperação de diversas espécies presentes nos resíduos da digestão da madeira que são atrativos para outras aplicações, tais como a lignina e açúcares, e em especial os lignossulfonatos, auxiliando também na recirculação de água do processo e na redução do teor poluente do efluente. Devido à sua gama de aplicações, existe hoje um mercado próprio de industrialização de lignossulfonatos obtidos a partir de subprodutos da indústria de papel, contexto em que se insere o interesse deste trabalho que teve como objetivo o estudo da recuperação por nanofiltração, no retentado, da fração de lignossulfonatos de baixa massa molar (<5000 g/mol) que não é recuperada pelo processo prévio de ultrafiltração do efluente de indústria de papel com processo sulfito, empregando membranas poliméricas comerciais NF e NF270, fornecidas pela Filmtec, Dow Liquid Separations, EUA. Os experimentos e as análises foram realizados de acordo com um planejamento experimental fatorial 2² (duas variáveis, dois níveis), em duplicata, onde as variáveis de processo estudadas foram: tipo de membrana e a pressão. As variáveis de resposta estudadas foram: fluxo de permeado, retenção baseada nos sólidos totais e na absorbância UV-VIS, massa molar média, condutividade e pH. A temperatura utilizada foi de 45°C e a placa suporte com 43,7% de área perfurada. O planejamento experimental possibilitou a determinação de modelos matemáticos para a previsão do fluxo de permeado de água pura e fluxo de permeado de amostra de lignossulfonato em função das variáveis estudadas, e para estes parâmetros os melhores resultados foram alcançados com as variáveis em nível superior: membrana NF270 e pressão 24 bar. A avaliação da retenção de lignossulfonatos, tanto através da análise de sólidos totais (diminuição de até 51,79% no teor de sólidos totais), bem como através da leitura de absorbância UV 280 nm (diminuição de até 84,26%, na absorbância), apresentou os melhores resultados com as variáveis em nível inferior: membrana NF e pressão 18 bar, como era esperado. Na análise da massa molar média de lignossulfonatos, realizada por Cromatografia de Permeação em Gel (GPC), o processo de nanofiltração apresentou capacidade de fracionamento, com Massa Molar Ponderal Média ( w M ) de 1994 g/mol para a alimentação, 2327 g/mol para o retentado e 1043 g/mol para o permeado. Para o estudo do conteúdo iônico (condutividade e pH) os resultados não apresentaram significância estatística. Estudo preliminar também foi realizado com o objetivo de avaliar a influência da área perfurada da placa-suporte da membrana no fluxo de permeado e permeabilidade hidráulica, utilizando-se três diferentes tipos de placa metálica como suporte para as membranas, todas com área total filtrante de membrana de 15,90 cm², mas com diferentes áreas perfuradas em relação à área total filtrante: 25,3%, 36,5% e 43,7% de área perfurada, respectivamente. Este estudo apresentou melhores resultados de fluxo para a maior área perfurada, indicando que para comparações entre valores de fluxo de permeado obtidos em células de fluxo perpendicular, é fundamental a informação da área perfurada da placa-suporte
Abstract: Membrane separation processes like ultrafiltration (UF) and nanofiltration (NF) are used in the pulp and paper industry to the recovery of several species present in the wood digest waste that are interesting to other applications as lignin, sugars and specially lignosulfonates, improving the recirculation of the water in the pulping process and the reduction of the pollutants in the waste water as well. Due to their wide range of applications, there is presently a specific market for lignosulfonates obtained from paper industry as byproducts, context where this study is inserted. The main objective is to recover by nanofiltration (NF) the low molecular weight lignosulfonates fraction (<5000 g/mol) from the permeate produced in a previous current ultrafiltration process of the paper industry effluent with sulphite process, using polymeric membranes NF and NF270, supplied by Filmtec, Dow Liquid Separations, USA. The assays and the analysis where conducted according to a 22 full factorial design (two variables, two levels), where the studied independent variables were: type of membrane and pressure. The studied dependent variables were: permeate flux, retention based on total solids and on UV-VIS absorbance, average molecular weight, conductivity and pH. The temperature used was 45°C and the perforated area of the support plate was 43.7%. The used full factorial design enabled the determination of mathematical models to predict the permeate flux of pure water and of lignosulfonate samples as a function of the studied variables. The best results to these parameters were achieved with the variables at the superior level values: membrane NF270 and pressure of 24 bar. The evaluation of the lignosulfonates retention using the total solids data (decrease of up to 51.79% in total solids in the permeate) or using the UV 280 nm absorbance data (decrease of up to 84.26% in absorbance in the permeate), as expected presented the best results with the variables at the inferior level values: membrane NF and pressure of 18 bar. In the analysis of the averaged molecular weight of lignosulfonates obtained by Gel Permeation Chromatography (GPC), the nanofiltration process presented fractioning capacity with Averaged Molecular Weight ( w M ) of 1994 g/mol to the sample, 2327 g/mol to the concentrated and 1043 g/mol to the permeated. The results have not presented statistical significance to the ionic content (conductivity and pH). Preliminary study were also conducted to estimate the influence of perforated area (%) of metallic plates used to support the membranes in the permeate flux and hydraulic permeability, using three different types of metallic support plates, each one with a total filtration membrane area of 15.90 cm2, but with different perforated areas (%) related to the total filtration area: 25.3%, 36.5% and 43.7%. This study presented better water permeate flux results to the biggest perforated area, indicating that when comparing permeate flux values obtained in perpendicular flux cells, the information of the perforated area (%) of the support plate is important
Doutorado
Ciencia e Tecnologia de Materiais
Doutor em Engenharia Química
Griffiths, Matthew H. "Rapid methods for testing the efficacy of sterilising grade filter membranes." Thesis, Loughborough University, 2000. https://dspace.lboro.ac.uk/2134/13514.
Full textHe, Yiting. "2D/3D Alumina Nanoplatelet Slit-Pore Membranes." Thesis, Université d'Ottawa / University of Ottawa, 2019. http://hdl.handle.net/10393/39966.
Full textCosta, Thiago Ranzani da. "Técnicas analíticas para autópsia de membranas de osmose reversa." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/42/42132/tde-20032012-162030/.
Full textFilter membrane systems, especially reverse osmosis, are being increasingly used in various business segments (pharmaceutical, water treatment, food and chemical) due to decrease in the price of the filter elements and high quality product. Although the price of reverse osmosis elements have fallen in recent times, the replacement of the part remains more expensive a reverse osmosis system. The autopsy of membranes is a technique used to investigate the cause that led to clogging of one factor contributing to the improvement of pre-treatment of water feeding and consequently increasing the life of the elements. This study aimed to improve the technique of autopsy reverse osmosis membranes by examining the volatilization of major inorganic compounds present in these membranes, modification the methodology for quantification of sugars and proteins, comparison of different techniques for removal of material deposited on the membranes and distribution analysis of biofilms on elements obscured reverse osmosis. The results showed that among the Inorganic volatilization was full of ammonium chloride and small variation in the compound ferric chloride, the quantification of proteins and sugars, by fortifying the samples showed different values when compared with values obtained directly the standard curve due to the difference in slope between the lines of and fortification standard, the results also showed that the blending was more efficient in removing adhered material when compared with the scraping and sonication and distribution of biofilms showed uniform the two elements analyzed.
Mertler, Michael. "Herstellung und Charakterisierung hoch poröser nanostrukturierter Filtermembranen." Karlsruhe : Forschungszentrum Karlsruhe, 2007. http://d-nb.info/987603566/34.
Full textShugman, Emad Musbah. "Cleaning of micro- and ultrafiltration membranes with infrasonic backpulsing." Thesis, Stellenbosch : University of Stellenbosch, 2009. http://hdl.handle.net/10019.1/3053.
Full textENGLISH ABSTRACT: Membrane fouling is universally considered to be one of the most critical problems in the wider application of membranes in filtration separation. Fouling is caused by the deposition of particles not only on the surface of the membrane, but also inside the membrane pores, which reduces permeate flux and leads to a reduction of the efficiency and the longevity of the membrane. The backpulsing cleaning method can be used to remove deposited foulants from the surface of the membrane, without having to shut down the plant. Ultrasonic time-domain reflectometry (UTDR) is a nondestructive technique, used to detect and measure the growth of fouling layer on the membrane surface during microfiltration and ultrafiltration processes. In this study flat-sheet microfiltration (MF) and ultrafiltration (UF) membranes were fouled during a cross-flow filtration processes using dextrin, yeast or alumina (feed pressure 100 kPa and feed flow rate 0.45 liter/minute), in a flat cell. Infrasound frequency backpulsing, in the permeate space, was used to clean the membranes. Backpulsing was carried out using the permeate water or soap solutions. The peak pressure amplitude of the pulses used to clean the membranes was 140 kPa, the pulsing was applied at a frequency of 6.7 Hz. The main objectives of this research were: (1) to obtain a fundamental understandimg of how foulants deposit on membrane surfaces and how the foulant deposits can be removed using the backpulsing cleaning technique during MF and UF, (2) to use the ultrasonic measurement technique for monitoring the growth and removal of the fouling layer on the membrane surface and (3) Use scanning electron microscopy (SEM) as a direct measurement technique to analyze the structure the foulant deposits on membrane surfaces before and after cleaning. Results showed that a flux value of between 55% and 98% of the clean water flux value can be achieved by backpulsing cleaning. UTDR was successfully applied to monitor membrane cleaning and provide information about the growth and removal of fouling layers on the membrane surface.
AFRIKAANSE OPSOMMING: Membraanaanvuiling is wêreldwyd bekend as een van die mees kritieke probleme wat die wyer aanwending van membrane vir skeidingsprosesse benadeel. Aanvuiling word veroorsaak deur die deponering van partikels, nie net op die oppervlak van die membraan nie, maar ook binne-in die membraanporieë, wat die volgende tot gevolg het: 'n afname in vloed deur die membraan, 'n afname in die effektiwiteit van die membraan, en 'n korter membraanleeftyd. Die teenpulsskoonmaakmetode kan gebruik word om die aanvuilingslaag vanaf die membranoppervlakte te verwyder sonder dat dit nodig is om die membraantoetsapparaat af te skakel. Ultrasoniese-tydsgebied-weerkaatsing (UTW) is 'n nie-vernietigende tegniek wat gebruik kan word om die groei van 'n aanvuilingslaag op 'n membraanoppervlakte tydens mikrofiltrasie (MF) of ultrafiltrasie (UF) te identifiseer en te meet. In hierdie studie is plat-vel MF en UF membrane bevuil gedurende 'n kruisvloeifiltrasieproses deur gebruik to maak van dekstraan, gis of alumina, in 'n plat sel. Infraklank-frekwensieteenpols, in die permeaatgebied, is gebruik om die membrane skoon te maak. Hiervoor is die proseswater of 'n seepoplossing gebruik. Die maksimum drukamplitude van die pulse wat gebruik is was 140 kPa, en die puls was aangewend teen 'n frekwensie van 6.7 Hz. Die hoofdoelwite van hierdie studie was die volgende: (1) om inligting in te win oor hoe aanvuilingsmateriale op membraanoppervlaktes gedeponeer word tydens MF en UF en hoe hulle verwyder kan word deur gebruik te maak van die teenpulsskoonmaaktegniek; (2) om van die teenpulsskoonmaaktegniek gebruik te maak om die groei van die bevuilingslaag asook die verwydering daarvan op die membraanoppervlakte te monitor; en (3) om van skandeerelektronmikroskopie (SEM) as 'n direkte analitiesetegniekgebruik te maak om die struktuur van die aanvuilingsmateriaal voor en na die die skoonmaakproses te analiseer. Deur gebruik te maak van teenpulsskoonmaak kon die membraanvloed tot tussen 55–98% van die oorspronklike suiwerwatervloed verbeter word. Sodoende is ultrasoniese-tydsgebiedweerkaatsing suksesvol gebruik om die skoonmaak van membrane te monitor asook om inligting in te win i.v.m. die groei en verwydering van die aanvuilingslae op die membraanoppervlaktes.
Benaoudia, Dihia. "Fonctionnalisation chimique de membranes nanoporeuses pour la mise en oeuvre de filtres commutatifs." Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC237.
Full textFiltration is a key process in chemical industry, water treatments and in biotechnology. It is crucial in emerging environment friendly technologies, which require to sort and to recycle efficiently and rapidly used materials and molecules. Filtration problems are numerous and can be classified according to the size and nature of the objects to be filtered (molecules, macromolecules, virus, particles, living cells), to the filters used (clothes, paper, sand, membranes). Active filtration devices, i.e. filters whose properties can be controlled by an external input, are of tremendous interest. Nuclear pore is an interesting source of inspiration for the elaboration of active filter answering to the pH or temperature. Such systems can be mimicked by the grafting of specific macromolecules in solid pores of diameter below 50 nm. In this work, we will describe the different steps to mimic such nuclear pore and to build a selective filter. For that, nanopores will be electrochemically grafted by a) molecules bearing various chemical functions deposited as compact ultrathin films (thickness below 5 nm) and b) by long macromolecules with hydrodynamic radius of 10 nm leading to a hairy nanopore. In both cases grafting, has been performed by diazonium electroreduction1 and the properties of the functionalized membrane has been studied by measuring DNA translocation through the nanopores by zeromode wave guide setup2 or by electrical measurements3. When using aminophenyl molecules having different chemical function we clearly demonstrate that DNA translocation can be tuned by the chemical functions deposited at the entrance of the nanopores. Indeed, we observed a clear shift of the curves DNA translocation frequency vs pressure towards higher pressures as compared to bare membranes (Fig. 4). Furthermore, this change can be related to the change of the effective radius of the pore due to the grafting. After that heterotelechelic poly (2-alkyll-2-oxazoline) has been synthesized and grafted4. Oxazoline brings a hydrophobicity control to the pore by the modulation of the lower critical solubility temperature (LCST) of those polymers. The first results toward active filter controlled by temperature will be described
Fradin, Benoit. "Fouling of microfiltration membranes for the dewatering of waste inorganic slurries." Thesis, University of Bath, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.311249.
Full textBeauchamp, Nicolas. "Methods for estimating reliability of water treatment processes : an application to conventional and membrane technologies." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2434.
Full textCarneiro, Eric Brandão. "Aplicação de absorvedores tipo membrana em cavidades e filtros acústicos." Florianópolis, SC, 2008. http://repositorio.ufsc.br/xmlui/handle/123456789/91861.
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Os absorvedores tipo membrana são absorvedores acústicos compostos de uma cavidade, cujo interior é parcialmente preenchido com material poroso, e por uma membrana flexível (no topo da cavidade) que vibra sob a ação de uma onda acústica. As perdas estruturais da membrana e as perdas proporcionadas pelo material poroso criam um sistema ressonante capaz de absorver a energia acústica de uma onda sonora em banda satisfatoriamente larga. Além de proporcionarem uma boa atenuação do ruído gerado por compressores, os absorvedores de membrana oferecem proteção ao material poroso contra os efeitos danosos do óleo lubrificante presente na cavidade do mesmo. Para se entender as características de atenuação sonora de absorvedores de membrana pesquisa foi realizada usando procedimentos experimentais e modelos computacionais. Utilizando um modelo analítico foi possível explorar como os parâmetros principais afetam a resposta do absorvedor de membrana. Um modelo computacional do absorvedor tipo membrana foi desenvolvido para a análise da interação entre fluido e estrutura. Simulou-se também a aplicação do absorvedor de membrana no interior de tubos e mufflers e o efeito resultante nas funções de transferência dos mesmos, bem como a redução que é capaz de introduzir na pressão sonora média quando o absorvedor de membrana é inserido em uma cavidade. Em todas as etapas do trabalho os resultados obtidos com os modelos computacionais foram comparados com dados experimentais obtidos no laboratório. Finalmente, uma análise crítica dos resultados pôde ser feita. Conclui-se que é possível obter boa atenuação do ruído aplicando-se os absorvedores de membrana em tubos, mufflers e cavidades, e que, apesar das limitações presentes nas simulações e das dificuldades e incertezas das medições experimentais, os modelos computacionais se mostram uma ferramenta importante e eficiente de análise. Membrane absorbers are acoustic absorbers consisting of a cavity partially filled with porous material, and a flexible membrane (at the top of the cavity) which vibrates in response to an incident sound wave. Membrane structural losses and the losses provided by the porous material create a resonant system able to absorb acoustic energy in a satisfactory wide band. Besides providing good compressor noise attenuation, membrane absorbers offer protection to the porous material against the damaging effects of lubricating oil inside a compressor cavity. In order to further understand the sound attenuation characteristics of membrane absorbers research was undertaken with experimental methods and computer-based models. Using an analytical model it was possible to explore how the main parameters affect the acoustic response of membrane absorbers. A computer model of the membrane absorber was then created which took into account the fluid-structure interaction between the membrane and the cavity of the absorber. A further simulation modelled the application of membrane absorbers to the interior of tubes and mufflers and the resultant effect on their transfer functions. The reduction of interior spatial averaged sound pressure was also investigated for membrane absorbers applied inside a cavity. Through all phases of this research results obtained through computer simulations were compared with experimental data obtained on the laboratory. Finally, the results have been subjected to a critical review. It was concluded that good noise reduction may be achieved through membrane absorber application in tubes, mufflers and cavities, and that, despite the limitation of the simulations and of difficulties and uncertainties in the measurements, the computer models were shown to be an important and effective analysis tool.
Brown, A. I. "An ultra scale-down approach to the rapid evaluation of pleated membrane cartridge filter performance." Thesis, University College London (University of London), 2011. http://discovery.ucl.ac.uk/1123181/.
Full textSilva, Layane Priscila de Azevedo. "Utiliza??o de membranas no p?s-tratamento de esgotos para reuso do permeado e aproveitamento do concentrado." Universidade Federal do Rio Grande do Norte, 2014. http://repositorio.ufrn.br:8080/jspui/handle/123456789/16012.
Full textCoordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The use of membrane filters in the post-treatment of sewage has been increasingly employed to obtain water quality, applicable to various forms of reuse. Despite the advantages presented using the permeate membranes, such as saving water and reducing water pollution, the concentrate generated in the process ends up being an inconvenience to the deployment of this technology due to lack of sustainable solutions for their management. Thus, the main objective of this research was to evaluate the use of membranes for microfiltration, ultrafiltration, nanofiltration and reverse osmosis concentrated in agriculture, using it as liquid fertilizer. The permeated membranes were also assessed in order to identify activities in which they could be reused. Five configurations were established from four types of membranes, so that each configuration represents a different system. The tests were conducted in batch mode, with triplicate for each configuration. The results indicated that permeated the microfiltration and ultrafiltration can be used in urban areas, in non-potable uses. Have the nanofiltration permeate can be reused in the industry, replacement cooling towers, and other non -potable uses required in the manufacturing unit. The permeate obtained in reverse osmosis met the intended uses for nanofiltration as well as the standards required for boiler feed, adding alkalizing being required to raise the pH to the recommended value. Concentrates generated in nanofiltration and reverse osmosis can be availed as liquid fertilizer in agriculture, but they must be diluted in the irrigation water, in order to adjust the salt concentration allowed for the least tolerant crops patterns
A utiliza??o de membranas filtrantes no p?s-tratamento de esgotos tem sido cada vez mais empregada para obten??o de ?gua com qualidade, aplic?vel a v?rias modalidades de re?so. Apesar das vantagens apresentadas com o uso do permeado de membranas, como a economia de ?gua e a redu??o da polui??o h?drica, o concentrado gerado no processo acaba sendo um inconveniente para a implanta??o dessa tecnologia, devido ? falta de solu??es sustent?veis para seu gerenciamento. Sendo assim, o principal objetivo dessa pesquisa foi avaliar o uso do concentrado de membranas de microfiltra??o, ultrafiltra??o, nanofiltra??o e osmose inversa na agricultura, utilizando-o como adubo l?quido. Os permeados das membranas tamb?m foram avaliados, a fim de identificar em que atividades os mesmos poderiam ser reutilizados. Foram estabelecidas cinco configura??es, a partir dos quatro tipos de membranas, de modo que cada configura??o representou um sistema distinto. Os ensaios foram realizados em batelada, com triplicata para cada configura??o. Os resultados indicaram que os permeados da microfiltra??o e ultrafiltra??o podem ser utilizados no meio urbano, em usos n?o pot?veis. J? o permeado da nanofiltra??o pode ser reutilizado na ind?stria, para reposi??o em torres de resfriamento, e nos demais usos n?o pot?veis requeridos na unidade fabril. O permeado obtido no processo de osmose inversa atendeu aos usos previstos para nanofiltra??o, bem como aos padr?es exigidos para alimenta??o de caldeiras, sendo necess?ria a adi??o de alcalinizante, para elevar o pH at? o valor recomendado. Os concentrados gerados na nanofiltra??o e osmose inversa podem ser aproveitados na agricultura como adubo l?quido, mas precisam ser dilu?dos na ?gua de irriga??o, a fim de adequar a concentra??o de sais aos padr?es permitidos para culturas menos tolerantes