聚偏氟乙烯-聚酰胺管式复合膜的分离性能研究

Study on Separation Performance of PVDF/PA Tubular Composite Membranes

以聚偏氟乙烯(PVDF)管式超滤膜为基膜,无水哌嗪(PIP)为水相单体,均苯三甲基酰氯(TMC)为有机相单体,采用界面聚合法制备了不同截留性能的PVDF/聚酰胺(PA)管式复合膜。研究了不同性能管式复合膜的截留分子量、膜表面荷电性测试、对无机盐的截留性能,以及染料废水脱盐的应用。实验结果表明,截留率R(Mg SO4)由97%~5%的复合膜相应的截留相对分子质量为300~45×10^(3)。对于4种无机盐的截留率由高到低依次为Na_(2)SO_(4)、MgSO_(4)、Na Cl、Mg Cl_(2);p H为4~11的环境下管式复合膜表面呈负电性;R(Mg SO_(4))分别为90%与97%的管式复合膜对染料的截留率在99.4%以上,透盐率高于80%,有效的实现了染料废水脱盐及染料回用。

Polyvinylidene fluoride(PVDF)/polyamide(PA)tubular composite membranes with different retention properties were prepared by interfacial polymerization using PVDF tubular ultrafiltration membrane as base membrane,piperazine(PIP)as aqueous phase monomer and trimethyl benzene chloride(TMC)as organic phase monomer.The molecular weight cut-off of tubular composite membranes with different properties,the measurement of membrane surface charge,the retention of inorganic salts and the application of desalination of dye wastewater were studied.The results showed that,the molecular weight of R(MgSO_(4))was 300~45×10^(3) when rejection rate R(MgSO_(4))was 97%~5%.The rejection rates of four inorganic salts from high to low were Na_(2) SO_(4),MgSO_(4),NaCl and MgCl_(2);the surface of tubular composite membrane was negatively charged at pH 4~11;the rejection rate of dye by tubular composite membrane with R(MgSO_(4))of 90%and 97%was above 99.4%,and the salt permeability was above 80%,which effectively realized desalination and reuse of dye wastewater.