PVDF/PMMA与PVDF/TPU共混膜抗污染性能研究及应用

Study on anti-fouling properties and application of PVDF/PMMA and PVDF/TPU blend membranes

观察新型五孔PVDF共混改性纤维膜SEM形貌特征,采用逐级通量法测定PVDF/PMMA和PVDF/TPU共混改性膜的临界通量,研究在次临界和超临界通量下A(PVDF/PMMA)与B(PVDF/TPU)2种管式膜组件的过滤和抗污染性能,并在次临界通量下处理地表水。结果表明,PVDF共混改性膜具有优良的微观结构,且膜B性能较好;膜A、B的临界通量分别为12 L/(m2.h)和10 L/(m2.h);膜组件B比膜组件A抗污染性能好。次临界通量下膜组件的运行比超临界通量下的稳定。与采用单独超滤处理某市地表水相比,2种膜组件采用混凝+超滤工艺的运行处理效果更好,且膜组件B比膜组件A处理效果佳。

SEM morphologies for novel five-bore PVDF blend modified membranes were observed.The critical fluxes of PVDF/PMMA and PVDF/TPU blend membranes were measured by the flux-step method.The filtration experiments at sub-critical flux and super-critical flux were performed.Then tubular membrane module A（PVDF/PMMA） and B（PVDF/TPU） were used to treat surface water.The results indicated that the PVDF blend modified membranes possessed excellent microstructure and the microstructure of membrane module B was better.The critical fluxes of two membrane modules were 12 L/（m2·h） and 10 L/（m2·h）,respectively.The anti-fouling properties of membrane module B were better than those of membrane module A.The operating characteristic under sub-critical flux was more stable than that of super-critical flux.Two membrane modules were used to treat surface water under sub-critical flux and the effects of those with coagulation as pretreatment were studied.The results showed that the wastewater treatment performance of coagulation-ultrafiltration combination process was better than that of ultrafiltration alone process,and the wastewater treatment performance of membrane module B was better than that of membrane module A.