Pvdf Membrane Hydrophilic Modification And Processing Of Low Concentrations Of Oily Wastewater

In this paper, hydrophilic modification was made by coating hydrophilic polymer-PVA to the surface of PVDF membrane.The modification condition of high hydrophilicity was confirmed, which was as follow. 1% concentration of PVA, 25min of reaction time at 50℃. And then the membrane was dried for 45 min at 50℃.After modification,the water flux is over 138.11L/m2h at the pressure of 0.2Mpa, and the least contact angle is 35°.The intensity and thermal stability of modified membrane was heightened accordiong to the result of tention and TG-DTA experiments. The pore structure and pore size distribution were observed by SEM and BET test, which shew no obvious change after modification. Mass -OH existed on the surface of modified membrane by reflection IR and XPS. So the physical performance, hydrophilicity, separability and pollution-resistant capability were improved much after modification.Oily wastewater, which the concentration was below 300mg/L, was treated by modified membrane. During this process, the effect of different additive PEG to membrane separation and pollution resistant was observed. The result indicated that the qualitiest membrane was made by 1%PVA and 20%PEG1000. Acquired the highest rejection ratio of 87.3% while the oil concentration of efflux was 9.144mg/L, reaching the water letting standard. During the filtration process, the highest permeation flux of oily wastewater was close to pure water flux. While the attenuation stabled . the permeation flux is around 30L/m2h.