Influence Of Membrane Structure On Anti-fouling Properties Of PVDF Membrane

As we know, today, the difficult problems are fouling of membrane during the application of membrane. Many ways, such as, the elect of membrane material, membrane surface-modified, the optimization design of membrane application technological conditions, have ever been studied in domestic and abroad; but few people do research on pore structure of membrane. Membrane pore structure includes symmetrical pore and asymmetrical pore. Now we know PVDF is a kind of material that has the greater anti-fouling property. In this article, two kinds of PVDF UF membrane with different outer surface pore structure but equivalent bubble point pressure and water flux were prepared by changing spinning condition, the one whose necks of pores lie on the surface of the membrane is smooth, this pore structure is named A model pore; the other one whose necks of pores are under membrane surface is relative rough this pore structure is named V model pore. Then, attenuation curve of membrane flux is studied through filtering representative different solution systems and changing different filtration conditions, and further illuminate the relation between membrane pore structure and anti-fouling. The results show that V model pore of membrane has better anti-fouling property. In succession, membrane that has dissimilar exterior configuration but the same fouling is washed reversely by water, and then different contaminative system is cleaned out by different chemical medicine, further reversion conditions of flux is researched. As a result, V model pore of is cleaned out easily. For the sake of improving anti-fouling property further, PVDF hollow fiber composition membrane is prepared by coating PVA on the surface of membrane. The results that the performance of anti-fouling is improved by coating PVA are demonstrated through filtering ovalbumin system and diesel oil system.