水中汞离子净化用共混改性超滤膜的研制

Research of Antifouling Ultrafiltration Membrane for Mercury Ion in Water Purification

采用相转化法,以聚偏氟乙烯(PVDF)、二硫化二苯并噻唑、聚乙二醇(PEG400)、吐温80和N,N-二甲基乙酰胺(DMAc)为原料制备具有汞离子吸附能力的二硫化二苯并噻唑共混改性聚偏氟乙烯超滤膜,并对影响超滤膜结构和性能的各个因素进行了研究。结果表明,在二硫化二苯并噻唑质量分数为0.4%、共混温度为70℃、共混时间为6h条件下所制备的超滤膜性能最佳。在25℃、0.1MPa下,膜的纯水通量为312 L/m2·h,卵清蛋白截留率为83.46%,接触角为72.35°;在25℃、pH值为7左右的条件下,膜吸附汞离子在6h达到吸附平衡,汞离子最大吸附量为0.331mg/cm2。

The antifouling polyvinylidene fluoride/dibenzothiazyl disulfide ultrafiltration membrane that could adsorb mercury ion was prepared by liquid - solid phase inversion method using polyvinylidene fluoride（PVDF）, dibenzothiazyl disulfide, Polyethylene glycol 400 （PEG400）, Tween 80 and N,N- dimethylacetamide（DMAc） as materials, and the various factors which influenced the structure and performance of ultrafiltration membrane was studied. The results show that, when dibenzothiazyl disulfide mass fraction is 0.4%, the reaction temperature is 70~C and the blending time is 6 hours, the antifouling polyvinylidene fluoride/dibenzothiazyl disulfide ultrafiltration membrane has excellent property. Under the conditions of 25℃and 0. 1 MPa, the pure water flux and ovalbumin retention rate of the modified membrane was 222 L/m2 ·h and 77.33 % respectively. The surface contact angle of modified membrane is 72.35°. Under the conditions of 25℃ and pH was about 7, the adsorption of mercury ion with membrane reached equilibrium after 6 hours, and the maximum adsorption capacity is 0. 331 rag/cm2.