A polypiperazine amide (PA)/polysulfone (PSF) thin film composite (TFC) was prepared by interfacial polymerization (IP) using a trimesoyl chloride hexane solution as the oil phase and a piperazine aqueous solution as ...A polypiperazine amide (PA)/polysulfone (PSF) thin film composite (TFC) was prepared by interfacial polymerization (IP) using a trimesoyl chloride hexane solution as the oil phase and a piperazine aqueous solution as the water phase on a porous polysulfone hollow fiber substrate. Its separating behaviors were investigated systematically to various salts such as NaCl, KCl, Na2SO4, MgCl2, CaCl2 and MgSO4, showing the highest rejection rate to Na2SO4, the second to MgSO4, the third to MgCl2 and CaCl2, and the lowest to KCl, NaCl, being 99%, 98%, 70%, 60%, 15% and 10% respectively. Under an increasing pressure or with time, the rejection rate of the TFC rises to a plateau. To various concentration of the feed, the rejection rate reduced gradually with the higher concentration.展开更多
Polyamide thin film composite membranes have dominated current reverse osmosis market on account of their excellent separation performances compared to the integrally skinned counterparts.Despite their very promising ...Polyamide thin film composite membranes have dominated current reverse osmosis market on account of their excellent separation performances compared to the integrally skinned counterparts.Despite their very promising separation performance,chlorine-induced degradation resulted from the susceptibility of polyamide toward chlorine attack has been regarded as the Achilles’s heel of polyamide thin film composite.The free chlorine species present during chlorine treatment can impair membrane performance through chlorination and depolymerization of the polyamide selective layer.From material point of view,a chemically stable membrane is crucial for the sustainable application of membrane separation process as it warrants a longer membrane lifespan and reduces the cost involved in membrane replacement.Various strategies,particularly those involved membrane material optimization and surface modifications,have been established to address this issue.This review discusses membrane degradation by free chlorine attack and its correlation with the surface chemistry of polyamide.The advancement in the development of chlorine resistant polyamide thin film composite membranes is reviewed based on the state-of-the-art surface modifications and tailoring approaches which include the in situ and postfabrication membrane modifications using a broad range of functional materials.The challenges and future directions in this field are also highlighted.展开更多
Drinking water scarcity is an ever-increasing global concern. This issue appears as a greater threat to the countries with no access to sea water resources or rivers, since their potential water resources are only lim...Drinking water scarcity is an ever-increasing global concern. This issue appears as a greater threat to the countries with no access to sea water resources or rivers, since their potential water resources are only limited to ground waters only. There are serious concerns with the treatment of ground water resources, including landfill leachates, agricultural contaminations(pesticides,herbicides, and fertilizers), and rural contaminations. Membrane separation has been proved to be the governing technology in water and wastewater treatment plants, as these methods are responsible for more than half of the market share of the world's desalination capacity. This study intends to offer a holistic view of the groundwater contamination with specific focus on Saskatchewan province in Canada, and the recent efforts in the groundwater treatment using thin film composite membrane technology. This study begins with an introduction of the general aspects of ground water and membrane separation, polluting agents, and their sources.It is followed by a discussion of Saskatchewan's groundwater status and various issues.Furthermore, the recent research that became available since 2010 is reviewed in details and the results are summarized with respect to purification efficiency. Different affecting parameters in a groundwater-thin film composite system are synthesized and an in-depth overview is presented.展开更多
基金China High-Tech R&D Program (863 Program) #2002AA302619 and Tianjin Science and Technology Develop Program #05YFGDGX10000-2
文摘A polypiperazine amide (PA)/polysulfone (PSF) thin film composite (TFC) was prepared by interfacial polymerization (IP) using a trimesoyl chloride hexane solution as the oil phase and a piperazine aqueous solution as the water phase on a porous polysulfone hollow fiber substrate. Its separating behaviors were investigated systematically to various salts such as NaCl, KCl, Na2SO4, MgCl2, CaCl2 and MgSO4, showing the highest rejection rate to Na2SO4, the second to MgSO4, the third to MgCl2 and CaCl2, and the lowest to KCl, NaCl, being 99%, 98%, 70%, 60%, 15% and 10% respectively. Under an increasing pressure or with time, the rejection rate of the TFC rises to a plateau. To various concentration of the feed, the rejection rate reduced gradually with the higher concentration.
基金support provided by the Ministry of Higher Education Malaysia under Malaysia Research University Network Grant(Grant No.4L862)the research support provided by Universiti Teknologi Malaysia.
文摘Polyamide thin film composite membranes have dominated current reverse osmosis market on account of their excellent separation performances compared to the integrally skinned counterparts.Despite their very promising separation performance,chlorine-induced degradation resulted from the susceptibility of polyamide toward chlorine attack has been regarded as the Achilles’s heel of polyamide thin film composite.The free chlorine species present during chlorine treatment can impair membrane performance through chlorination and depolymerization of the polyamide selective layer.From material point of view,a chemically stable membrane is crucial for the sustainable application of membrane separation process as it warrants a longer membrane lifespan and reduces the cost involved in membrane replacement.Various strategies,particularly those involved membrane material optimization and surface modifications,have been established to address this issue.This review discusses membrane degradation by free chlorine attack and its correlation with the surface chemistry of polyamide.The advancement in the development of chlorine resistant polyamide thin film composite membranes is reviewed based on the state-of-the-art surface modifications and tailoring approaches which include the in situ and postfabrication membrane modifications using a broad range of functional materials.The challenges and future directions in this field are also highlighted.
基金the Department of Chemical and Biological Engineering at the University of Saskatchewan for the support provided
文摘Drinking water scarcity is an ever-increasing global concern. This issue appears as a greater threat to the countries with no access to sea water resources or rivers, since their potential water resources are only limited to ground waters only. There are serious concerns with the treatment of ground water resources, including landfill leachates, agricultural contaminations(pesticides,herbicides, and fertilizers), and rural contaminations. Membrane separation has been proved to be the governing technology in water and wastewater treatment plants, as these methods are responsible for more than half of the market share of the world's desalination capacity. This study intends to offer a holistic view of the groundwater contamination with specific focus on Saskatchewan province in Canada, and the recent efforts in the groundwater treatment using thin film composite membrane technology. This study begins with an introduction of the general aspects of ground water and membrane separation, polluting agents, and their sources.It is followed by a discussion of Saskatchewan's groundwater status and various issues.Furthermore, the recent research that became available since 2010 is reviewed in details and the results are summarized with respect to purification efficiency. Different affecting parameters in a groundwater-thin film composite system are synthesized and an in-depth overview is presented.
