Modification of Tunisian clay membrane surface by silane grafting: Application for desalination with Air Gap Membrane Distillation process

Khemakhem, Sabeur; Amar, Raja Ben

doi:10.1016/j.colsurfa.2011.07.033

Cited by 63 publications

(29 citation statements)

References 36 publications

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“…This value has to be larger than 90°; recommended value is around 130°. In extreme cases it is able to reach value of 180° [18]. In general, smaller pore size, greater contact angle and surface tension increase the value of LEP.…”

Section: Theoretical Description Of Liquid Entry Pressurementioning

confidence: 99%

Theoretical and Experimental Approaches of Liquid Entry Pressure Determination in Membrane Distillation Processes

Rácz¹,

Kerker²,

Kovács³

et al. 2014

Period. Polytech. Chem. Eng.

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Membrane distillation (MD) is a thermally driven separation process that employs a hydrophobic membrane as a barrier for IntroductionMembrane distillation (MD) is a thermally driven separation technique using microporous hydrophobic membranes and performing on the principles of vapor-liquid equilibrium under different configurations. In this process, only volatile compounds (mainly water) of the feed stream evaporate at the membrane pore entrance, cross the membrane pores in vapor phase to finally be either condensed or removed as a vapor from a membrane module. The hydrophobic nature of the membrane prevents the pores from wetting by capillary forces. MD is known as a promising technology for many applications such as desalting seawater, brackish water, highly saline water [1,2], and removing organic compounds and heavy metals from aqueous solutions [3,4]. MD has also been used to manage waste water such as radioactive waste waters, oily waste waters [5], where the product could be safely discharged to the environment or the waste streams could be reused in an appropriate industrial activity. In biotechnology and food processing applications, MD has also been found as a promising tool, for instance, for removing ethanol and other metabolites from fermentation broths [6], for gentle concentration of valuable compounds in fruit juices [7], and in herb extract such as Ginseng [8].MD has many attractive features as compared to conventional separation processes. Low operating temperatures (~30-70°C) is one of them since the feed is not necessarily heated up to the boiling point like in thermal distillation. Thus, MD may advantageously utilize alternative energy sources, such as solar energy, geothermal energy, waste heats from power plant, etc. [9]. Compared with pressure driven membrane filtration processes such as nanofiltration or reverse osmosis, lower operating pressure translates to lower equipment costs and increased process safety. It is worth highlighting that membrane fouling in MD seems to be less of a problem for many applications than that in pressure-driven filtration processes [10].MD is, however, attended by some drawbacks. Compared to reverse osmosis, MD is known to have a lower permeate flux, and the susceptibility of permeate flux to processing conditions, particularly to temperature and concentration, is considerably high. Also, the trapped air within the membrane pores

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Section: Theoretical Description Of Liquid Entry Pressurementioning

confidence: 99%

Theoretical and Experimental Approaches of Liquid Entry Pressure Determination in Membrane Distillation Processes

Rácz¹,

Kerker²,

Kovács³

et al. 2014

Period. Polytech. Chem. Eng.

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“…The morphology of these membranes is typically more homogeneous than that of polymeric membranes as the crystallites forming the network of the membranes are even in size (SEMs in Figure 22a,b). Although most work utilises commercial supporting materials, other works investigated the use of natural clay [242], in the form of aluminium phyllosilicates, to process thin membranes. The advantages of ceramic membranes over organic membranes are associated with their mechanical stability over large pH ranges and when exposed to aggressive chemical environments.…”

Section: Ceramic Membranesmentioning

confidence: 99%

“…The materials exhibit high surface energy and are therefore naturally hydrophilic, requiring functionalisation with hydrophobic groups in order to satisfy MD requirements [244,245]. Short aliphatic oligomers, alkoxy-silanes or fluoro-polymers can be easily grafted onto the surface of the membrane following a sol-gel approach, where the hydroxyl groups naturally present on the metal oxide are used to react with functional groups of the oligomers [242,[246][247][248].…”

Section: Ceramic Membranesmentioning

confidence: 99%

Advances in Membrane Distillation for Water Desalination and Purification Applications

Camacho

Dumée

Zhang

et al. 2013

Water

642

342

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Membrane distillation is a process that utilizes differences in vapor pressure to permeate water through a macro-porous membrane and reject other non-volatile constituents present in the influent water. This review considers the fundamental heat and mass transfer processes in membrane distillation, recent advances in membrane technology, module configurations, and the applications and economics of membrane distillation, and identifies areas that may lead to technological improvements in membrane distillation as well as the application characteristics required for commercial deployment. Keywordsa function of temperature, vapor pressure, and of the gas molecular mass K 0 membrane characteristic defined by Equation (9) Kn Knudsen number K(T) a function of temperature and molecular weight of the gas l mean free path of the molecules l m distance between parallel spacer fibres (m) LEP Limit Entry Pressure (kPa) M molecular mass (g/mol) M w molecular weights of water (g/mol) M a molecular weights of air (g/mol) n number of CNTs per unit cross section in bucky-paper P pressure in the air gap (kPa) half time to reach the maximum intensity-laser flash technique (s) t proportion of conductive heat (balance due to evaporative heat) loss through the membrane T mean temperature in the pores (K)

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“…Os resultados demonstraram ser bastante promissores para serem utilizados como um passo de clarificação prévia no tratamento de águas de indústrias têxteis. Khemakhem e Amar [3] obtiveram membranas cerâmicas de argila para aplicação em processos de destilação. Em seus resultados os autores atingiram taxas de rejeição elevada de sal superior a 99%.…”

Section: Introductionunclassified

Membranas cerâmicas assimétricas tubulares: influência do tempo de deposição da camada filtrante na morfologia das membranas

Silva¹,

Lira²,

Freitas³

et al. 2015

Matéria (Rio J.)

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RESUMOEsse trabalho tem como objetivo obter membranas cerâmicas assimétricas para aplicação em processos de microfiltração e avaliar a influência do tempo de deposição (5 e 10 s) de uma dispersão de argila sobre um suporte tubular de alumina comercial e bentonita. O suporte tubular foi caracterizado por microscopia ótica e eletrônica de varredura e por porosimetria. A membrana assimétrica foi caracterizada por microscopia eletrônica de varredura e por porosimetria. Os resultados mostraram suportes porosos com espessura de 1092mm, diâmetro médio de poro de 0,99 mm e porosidade de 39%. A membrana assimétrica foi obtida com sucesso para os tempos de deposição avaliados, sendo classificada para aplicações em processos de microfiltração atingindo diâmetro médio de poro de 0,25 mm e porosidade de 35%.Palavras-chave: membrana assimétrica, membrana tubular, deposição, microfiltração. ABSTRACTThis paper aims to obtain asymmetric ceramic membranes for application in microfiltration processes and evaluate the influence of the deposition time (5 and 10 s) of a clay dispersion on commercial alumina and bentonite tubular support. The tubular support was characterized by optical and scanning electron microscopy and porosimetry. The asymmetric membrane was characterized by scanning electron microscopy and porosimetry. The results showed porous substrates with thickness of 1092mm, average pore diameter of 0.99 mm and porosity of 39%. The asymmetric membrane was successfully obtained for the evaluated deposition times, being classified for microfiltration processes applications.Keywords: asymmetric membrane, tubular membrane, deposition, microfiltration. INTRODUÇÃOA tecnologia de separação com membranas tem sido amplamente utilizada em biotecnologia, indústrias farmacêuticas e de alimentos ou para tratar outros efluentes industriais. Essa tecnologia oferece uma ampla gama de procedimentos capazes de recuperar, concentrar ou purificar solventes valiosos em todos estes campos científicos [1].As membranas inorgânicas apresentam vantagens sobre as orgânicas por poderem atuar sob condições em que as orgânicas apresentam restrições, como por exemplo, na presença de solventes, elevadas temperaturas e pressões. Procedimentos agressivos de limpeza química e/ou mecânica e esterilização são geralmente empregados em membranas e são propensos a causar danos na estrutura da membrana especialmente para as membranas orgânicas [2]. Entretanto, as membranas inorgânicas são normalmente mais caras do que as orgâ-nicas habituais. Nesse sentido, novas pesquisas com membranas usando materiais cerâmicos de custo mais baixo devem difundir o uso da tecnologia de membranas, especialmente para países emergentes, onde muitos problemas ambientais podem ser resolvidos com a utilização de membranas.

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Modification of Tunisian clay membrane surface by silane grafting: Application for desalination with Air Gap Membrane Distillation process

Cited by 63 publications

References 36 publications

Theoretical and Experimental Approaches of Liquid Entry Pressure Determination in Membrane Distillation Processes

Theoretical and Experimental Approaches of Liquid Entry Pressure Determination in Membrane Distillation Processes

Advances in Membrane Distillation for Water Desalination and Purification Applications

Membranas cerâmicas assimétricas tubulares: influência do tempo de deposição da camada filtrante na morfologia das membranas

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