A Brief Introduction to Hollow Fiber Membranes for Separation
Because of their matured preparing technologies,self-supporting,high packing density of modules,being able back-washing and lower production cost,and at the same time,because of their advantages of simple separation processes,saving energy,smaller footprint,lower operating cost and deep treatment for some water bodies,hollow fiber membranes have been widely used in water treatment fields and so on.The membrane materials,membrane-making technologies and membrane formation mechanisms,membrane structure and performance as well as their identification,different module types and application technologies were given more systematically in the paper.The development trend for hollow fiber membranes was also briefly mentioned.Most of membrane materials can be used as the materials for hollow fiber membranes.Cellulose and its derivatives,polysulfone(PS),polyacrylonitrile(PAN),polyethylene(PE),polypropylene(PP),polyvinyl chloride(PVC),polyvinylidene fluoride(PVDF),aromatic polyamides and polyimides etc.are common membrane materials.As well as inorganic materials such as ceramics,zeolite molecular sieve and glasses are also involved.There are mainly 3 technologies for manufacturing hollow fiber membranes: solution phase inversion,melt spinning (stretched) and thermo-induced phase separation.Hollow fiber membranes from Cellulose and its derivatives,PS,PAN and aromatic polyamides and polyimides are mainly produced by solution phase inversion.Hollow fiber membranes from PE,PP and PVDF are mainly produced by melt spinning and thermo-induced phase separation.As other membranes,the structure factors of hollow fiber membranes include symmetric and asymmetric,dense skin layer and porous layer,crystallization and orientation,pore size,pore size distribution and porosity etc.There are different performances for various hollow fiber membranes based on their application,mainly including rejection ratio,molecular weight cut-off (MWCO),(pure water) flux,pure water permeability coefficient,reflect coefficient,solute permeate coefficient,permeate flux and separation factor etc.According to different uses,there are many types of membrane modules to be selected.Such as radial flow with one sealed end,axial flow with one sealed end,pressure-in with double sealed ends,pressure-out with double sealed ends,screen type,sea weed type,hanging type and bundle type etc.Technologies for membrane application are selected on different feeds to be treated,such as one-stage process for sea water desalination,circulated dialysis for artificial kidney,two way flow,continuous membrane filtration and processes of membrane bioreactor for common water treatment etc.Like other membranes,hollow fiber membranes,as a main and distinctive variety of membranes,will play important roles in membrane separation with the modification of membrane materials,optimization of membrane-making processes,controlling of membrane structure and performance,improvement of module types and development of new application technologies.
Hollow fiber membranes Water treatment Hemodialysis Desalination Membrane bioreactor
Congjie Gao
Development Center of Water Treatment Technology,No. 50 Wenyi Road (west),Hangzhou 310012,China
国际会议
杭州
英文
2008-10-15（万方平台首次上网日期，不代表论文的发表时间）