Thin-film composite(TFC)reverse osmosis(RO)membranes have attracted considerable attention in water treatment and desalination processes due to their specific separation advantages.Nevertheless,the trade-off effect be...Thin-film composite(TFC)reverse osmosis(RO)membranes have attracted considerable attention in water treatment and desalination processes due to their specific separation advantages.Nevertheless,the trade-off effect between water flux and salt rejection poses huge challenges to further improvement in TFC RO membrane performance.Numerous research works have been dedicated to optimizing membrane fabrication and modification for addressing this issue.In the meantime,several reviews summarized these approaches.However,the existing reviews seldom analyzed these methods from a theoretical perspective and thus failed to offer effective optimization directions for the RO process from the root cause.In this review,we first propose a mass transfer model to facilitate a better understanding of the entire process of how water and solute permeate through RO membranes in detail,namely the migration process outside the membrane,the dissolution process on the membrane surface,and the diffusion process within the membrane.Thereafter,the water and salt mass transfer behaviors obtained from model deduction are comprehensively analyzed to provide potential guidelines for alleviating the trade-off effect between water flux and salt rejection in the RO process.Finally,inspired by the theoretical analysis and the accurate identification of existing bottlenecks,several promising strategies for both regulating RO membranes and optimizing operational conditions are proposed to further exploit the potential of RO membrane performance.This review is expected to guide the development of high-performance RO membranes from a mass transfer theory standpoint.展开更多
In nearly all chemical and petrochemical systems, separation of products generally accounts for more than 50% of the capital cost and the greatest part of the energy consumption. It is generally believed that membrane...In nearly all chemical and petrochemical systems, separation of products generally accounts for more than 50% of the capital cost and the greatest part of the energy consumption. It is generally believed that membrane systems can offer benefits in both reducing the energy consumption of the separation stages and lowering the capital expenditure （CAPEX）. Microporous ceramic membranes have the potential to overcome the limitation in polymer membranes operation, which has been the subject of a large amount of research worldwide in the last two decades. And most of the research has aimed at the production of the asymmetric multilayered membrane based on amorphous oxides by sol-gel techniques. The paper is to give an overview of publications on ceramic membranes, including less common materials of titania, zirconia, which can be used for pervaporation in corrosive media. Commercially available microporous membranes based on these membrane materials and the membrane economics are also summarized.展开更多
Effective utilization of sustainable energies necessitates the development of electrochemical energy conversion and storage devices,where the catalysts and ion-conducting membranes are two core components.Anion exchan...Effective utilization of sustainable energies necessitates the development of electrochemical energy conversion and storage devices,where the catalysts and ion-conducting membranes are two core components.Anion exchange membrane water electrolysis(AEM-WE)has been widely regarded as the next-generation technology for green hydrogen production because it provides a feasible route to achieve non-precious-metal catalyzed green energy conversion[1].Currently,the design of high-performance catalysts for the anodic oxygen evolution reaction(OER)and cathodic hydrogen evolution reaction(HER)has attracted wide attention and made impressive achievements[2],but the development of the indispensable AEM is relatively less mature[3].Therefore,designing AEMs with high conductivity,long-term stability,and mechanical strength represents one of the key challenges to realizing effective and economical water electrolysis with AEM-WE.展开更多
Thin-film microextraction（TFME）,a new geometry for solid-phase microextraction,has become an attractive sample-preparation technique.Compared to other microextraction approaches,the sensitivity of this technique was...Thin-film microextraction（TFME）,a new geometry for solid-phase microextraction,has become an attractive sample-preparation technique.Compared to other microextraction approaches,the sensitivity of this technique was enhanced without sacrificing the sampling time due to the high surface area-tovolume ratio together with the increase of extraction-phase volume.In this paper,a new TFME method based on poly（vinylidene fluoride） membrane was developed for the extraction of benzoylurea insecticides（diflubenzuron,triflumuron,hexaflumuron and teflubenzuron） from water samples followed by their determination with high performance liquid chromatography-diode array detection.Under the optimal conditions,good linearity was observed over the concentration range of 0.5-100.0 ng/mL with correlation coefficient greater than 0.9994.The limits of detection（S/N = 3） of the method for the target analytes were 0.1 ng/mL.Mean recoveries ranged from 87.7% to 103.9% with relative standard deviations lower than 6.5%.The results indicated that the developed TFME method is simple,efficient,and cost effective.展开更多
Formic acid（FA） dehydrogenation has attracted a lot of attentions since it is a convenient method for H_2 production. In this work, we designed a self-supporting fuel cell system, in which H_2 from FA is supplied in...Formic acid（FA） dehydrogenation has attracted a lot of attentions since it is a convenient method for H_2 production. In this work, we designed a self-supporting fuel cell system, in which H_2 from FA is supplied into the fuel cell, and the exhaust heat from the fuel cell supported the FA dehydrogenation. In order to realize the system, we synthesized a highly active and selective homogeneous catalyst Ir Cp＊Cl_2 bpym for FA dehydrogenation. The turnover frequency（TOF） of the catalyst for FA dehydrogenation is as high as7150 h^（-1）at 50°C, and is up to 144,000 h^（-1）at 90°C. The catalyst also shows excellent catalytic stability for FA dehydrogenation after several cycles of test. The conversion ratio of FA can achieve 93.2%, and no carbon monoxide is detected in the evolved gas. Therefore, the evolved gas could be applied in the proton exchange membrane fuel cell（PEMFC） directly. This is a potential technology for hydrogen storage and generation. The power density of the PEMFC driven by the evolved gas could approximate to that using pure hydrogen.展开更多
The formation of a dynamic membrane(DM)was investigated using polyethylene glycol(PEG)(molecular weight of 35000 g/mol,concentration of 1 g/L).Two natural organic matters(NOM),Dongbok Lake NOM(DLNOM)and Suwannee River...The formation of a dynamic membrane(DM)was investigated using polyethylene glycol(PEG)(molecular weight of 35000 g/mol,concentration of 1 g/L).Two natural organic matters(NOM),Dongbok Lake NOM(DLNOM)and Suwannee River NOM(SRNOM)were used in the ultrafiltration experiments along with PEG.To evaluate the effects of the DM with PEG on ultrafiltration,various transport experiments were conducted,and the analyses of the NOM in the membrane feed and permeate were performed using high performance size exclusion chromatography,and the effective pore size distribution(effective PSD)and effective molecular weight cut off(effective MWCO)were determined.The advantages of DM formed with PEG can be summarized as follows:(1)PEG interferes with NOM transmission through the ultrafiltration membrane pores by increasing the retention coefficient of NOM in UF membranes,and(2)low removal of NOM by the DM is affected by external factors,such as pressure increases during UF membrane filtration,which decreases the effective PSD and effective MWCO of UF membranes.However,a disadvantage of the DM with PEG was severe flux decline;thus,one must be mindful of both the positive and negative influences of the DM when optimizing the UF performance of the membrane.展开更多
基金supported by the Natural Science Foundation of Sichuan Province(No.2022NSFSC1042)National Natural Science Foundation of China(No.52200051)+1 种基金Outstanding Youth Fund of Heilongjiang Natural Science Foundation(No.YQ2023E021)Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.HC202236).
文摘Thin-film composite(TFC)reverse osmosis(RO)membranes have attracted considerable attention in water treatment and desalination processes due to their specific separation advantages.Nevertheless,the trade-off effect between water flux and salt rejection poses huge challenges to further improvement in TFC RO membrane performance.Numerous research works have been dedicated to optimizing membrane fabrication and modification for addressing this issue.In the meantime,several reviews summarized these approaches.However,the existing reviews seldom analyzed these methods from a theoretical perspective and thus failed to offer effective optimization directions for the RO process from the root cause.In this review,we first propose a mass transfer model to facilitate a better understanding of the entire process of how water and solute permeate through RO membranes in detail,namely the migration process outside the membrane,the dissolution process on the membrane surface,and the diffusion process within the membrane.Thereafter,the water and salt mass transfer behaviors obtained from model deduction are comprehensively analyzed to provide potential guidelines for alleviating the trade-off effect between water flux and salt rejection in the RO process.Finally,inspired by the theoretical analysis and the accurate identification of existing bottlenecks,several promising strategies for both regulating RO membranes and optimizing operational conditions are proposed to further exploit the potential of RO membrane performance.This review is expected to guide the development of high-performance RO membranes from a mass transfer theory standpoint.
基金The authors would like to thank the National Natural Science Foundation of China(No.20676149)the Scientific Research Foundation for the Returned 0verseas Chinese Scholars,State Education Ministrythe research foundation of the State Key Laboratory of Heavy 0il Processing,China University of Petroleum(Beijing),for financial support.
文摘In nearly all chemical and petrochemical systems, separation of products generally accounts for more than 50% of the capital cost and the greatest part of the energy consumption. It is generally believed that membrane systems can offer benefits in both reducing the energy consumption of the separation stages and lowering the capital expenditure （CAPEX）. Microporous ceramic membranes have the potential to overcome the limitation in polymer membranes operation, which has been the subject of a large amount of research worldwide in the last two decades. And most of the research has aimed at the production of the asymmetric multilayered membrane based on amorphous oxides by sol-gel techniques. The paper is to give an overview of publications on ceramic membranes, including less common materials of titania, zirconia, which can be used for pervaporation in corrosive media. Commercially available microporous membranes based on these membrane materials and the membrane economics are also summarized.
基金supported by the National Key Research and Development Program of China (2022YFA0911900)the start-up packages from Westlake Universitythe Research Center for Industries of the Future (RCIF) at Westlake University。
文摘Effective utilization of sustainable energies necessitates the development of electrochemical energy conversion and storage devices,where the catalysts and ion-conducting membranes are two core components.Anion exchange membrane water electrolysis(AEM-WE)has been widely regarded as the next-generation technology for green hydrogen production because it provides a feasible route to achieve non-precious-metal catalyzed green energy conversion[1].Currently,the design of high-performance catalysts for the anodic oxygen evolution reaction(OER)and cathodic hydrogen evolution reaction(HER)has attracted wide attention and made impressive achievements[2],but the development of the indispensable AEM is relatively less mature[3].Therefore,designing AEMs with high conductivity,long-term stability,and mechanical strength represents one of the key challenges to realizing effective and economical water electrolysis with AEM-WE.
基金Financial supports from the National Natural Science Foundation of China(No.31171698)the Innovation Research Program of Department of Education of Hebei for Hebei Provincial Universities (No.LJRC009)+1 种基金the Scientific and Technological Research Foundation of Department of Education of Hebei Province(No. ZD20131033)the Natural Science Foundation of Hebei(No. B2012204028)
文摘Thin-film microextraction（TFME）,a new geometry for solid-phase microextraction,has become an attractive sample-preparation technique.Compared to other microextraction approaches,the sensitivity of this technique was enhanced without sacrificing the sampling time due to the high surface area-tovolume ratio together with the increase of extraction-phase volume.In this paper,a new TFME method based on poly（vinylidene fluoride） membrane was developed for the extraction of benzoylurea insecticides（diflubenzuron,triflumuron,hexaflumuron and teflubenzuron） from water samples followed by their determination with high performance liquid chromatography-diode array detection.Under the optimal conditions,good linearity was observed over the concentration range of 0.5-100.0 ng/mL with correlation coefficient greater than 0.9994.The limits of detection（S/N = 3） of the method for the target analytes were 0.1 ng/mL.Mean recoveries ranged from 87.7% to 103.9% with relative standard deviations lower than 6.5%.The results indicated that the developed TFME method is simple,efficient,and cost effective.
基金financial support granted by Ministry of Science and Technology of China(Nos.2016YFE0105700,2016YFA0200700)the National Natural Science Foundation of China(Nos.21373264,21573275)+2 种基金the Natural Science Foundation of Jiangsu Province(No.BK20150362)Suzhou Institute of Nano-tech and Nano-bionics(No.Y3AAA11004)Thousand Youth Talents Plan(No.Y3BQA11001)
文摘Formic acid（FA） dehydrogenation has attracted a lot of attentions since it is a convenient method for H_2 production. In this work, we designed a self-supporting fuel cell system, in which H_2 from FA is supplied into the fuel cell, and the exhaust heat from the fuel cell supported the FA dehydrogenation. In order to realize the system, we synthesized a highly active and selective homogeneous catalyst Ir Cp＊Cl_2 bpym for FA dehydrogenation. The turnover frequency（TOF） of the catalyst for FA dehydrogenation is as high as7150 h^（-1）at 50°C, and is up to 144,000 h^（-1）at 90°C. The catalyst also shows excellent catalytic stability for FA dehydrogenation after several cycles of test. The conversion ratio of FA can achieve 93.2%, and no carbon monoxide is detected in the evolved gas. Therefore, the evolved gas could be applied in the proton exchange membrane fuel cell（PEMFC） directly. This is a potential technology for hydrogen storage and generation. The power density of the PEMFC driven by the evolved gas could approximate to that using pure hydrogen.
基金the National Research Laboratory Program by the Korea Science and Engineering Foundation(NOM Lab:R0A-2007-000-20055-0).
文摘The formation of a dynamic membrane(DM)was investigated using polyethylene glycol(PEG)(molecular weight of 35000 g/mol,concentration of 1 g/L).Two natural organic matters(NOM),Dongbok Lake NOM(DLNOM)and Suwannee River NOM(SRNOM)were used in the ultrafiltration experiments along with PEG.To evaluate the effects of the DM with PEG on ultrafiltration,various transport experiments were conducted,and the analyses of the NOM in the membrane feed and permeate were performed using high performance size exclusion chromatography,and the effective pore size distribution(effective PSD)and effective molecular weight cut off(effective MWCO)were determined.The advantages of DM formed with PEG can be summarized as follows:(1)PEG interferes with NOM transmission through the ultrafiltration membrane pores by increasing the retention coefficient of NOM in UF membranes,and(2)low removal of NOM by the DM is affected by external factors,such as pressure increases during UF membrane filtration,which decreases the effective PSD and effective MWCO of UF membranes.However,a disadvantage of the DM with PEG was severe flux decline;thus,one must be mindful of both the positive and negative influences of the DM when optimizing the UF performance of the membrane.
