PA/PDA/CPVC复合纳滤膜的制备及其在模拟染料废水处理中的应用

Preparation of PA/PDA/CPVC composite nanofiltration membrane and its application in simulated dye wastewater treatment

以氯化聚氯乙烯(CPVC)超滤膜为基膜,将多巴胺(DA)和聚乙烯亚胺(PEI)共沉积后,与均苯三甲酰氯(TMC)进行界面聚合制备了聚酰胺/聚多巴胺/氯化聚氯乙烯(PA/PDA/CPVC)复合纳滤膜。通过傅里叶变换红外光谱仪、扫描电子显微镜、原子力显微镜、接触角仪对PA/PDA/CPVC复合纳滤膜选择层的化学结构、微观结构、表面粗糙度及亲水性进行了表征,探讨了PEI质量浓度对复合纳滤膜结构和性能的影响。研究结果表明:随着PEI质量浓度的增大,复合纳滤膜表面变得光滑、亲水性增强,通量先增大后减小;PEI质量浓度为5g/L时,复合纳滤膜的通量达到最大。PA/PDA/CPVC复合纳滤膜对染料活性黑5(RB5)的截留率皆高于94%,而对NaCl的截留率低于5.6%,说明该复合纳滤膜能够对染料和盐进行较好的分离,复合纳滤膜在模拟RB5染料废水处理中稳定性良好。

Polyamide/polydopamine/chlorinated polyvinyl chloride(PA/PDA/CPVC) composite nanofiltration membrane was prepared by interfacial polymerization of trimesoyl chloride(TMC) with dopamine(DA) and polyethyleneimine(PEI) co-deposited on chlorinated polyvinyl chloride(CPVC) ultrafiltration membrane.The chemical structure,microstructure,surface roughness and hydrophilicity of the selective layer of PA/PDA/CPVC composite nanofiltration membrane were investigated by ATR-FTIR,SEM,AFM and water contact angle.The effect of PEI mass concentration on the structure and properties of composite nanofiltration membrane was explored.The results showed that with the increase of PEI concentration,the surface of composite nanofiltration membrane became smooth,the hydrophilicity was enhanced,and the flux increased first and then decreased.When the concentration of PEI was 5g/L,the flux of the composite nanofiltration membrane reached the maximum.The rejection rate of dye reactive black 5(RB5) by PA/PDA/CPVC composite nanofiltration membrane was higher than 94%,while the rejection rate of NaCl was lower than 5.6%,indicating that the composite nanofiltration membrane could effectively separate dyes and salts.In addition,PA/PDA/CPVC composite nanofiltration membrane had good stability in simulated RB5 dye wastewater treatment.