Abstract:

Polyvinyl alcohol micro-sphere (PVA-MS) was prepared from PVA and glutaraldehyde after emulsification and cross linking with hemiacetal.FTIR analysis and zeta potential indicated presence of several hydroxy groups and electronegativity.Two PVA-MS dynamic membranes (DMs) of standard blockage filtration type without filter cake and full blockage filtration type were prepared from industrial filter cloth substrate membrane by using self-assembly coating (SA) and pre-coating (PC) methods, and the PVA-MS densities of the self-assembly coating dynamic membrane (SADM) and pre-coating dynamic membrane (PCDM) were determined to be 2.25 g•m^-2 and 62.0 g•m^-2, respectively, and their retention particle diameters were 2.1 μm and 0.4 μm respectively.PVA-MS DMs could improve hydrophilicity and negative charge of the filter cloth substrate membrane significantly.The PCDM rejection abilities for the sludge supernatant with turbidity 21.34 NTU and TOC 18.3 mg•L^-1 were improved by 20% and 30% respectively as compared with the substrate membrane.But, SADM had little impact on the rejection of turbidity and TOC.The efficiency of physical cleaning for the irreversible membrane fouling would increase with increasing coated MS on the filter cloth.SADM could be maintained on the filter cloth even after frequent chemical cleaning; however, regarding the PCDM, physical cleaning could eliminate the irreversible fouling completely, but a repeated precoating was needed to maintain the MS layer on the surface of the filter cloth.