PA/PDA/PVDF复合纳滤膜的制备及其在模拟RB5染料废水处理中的应用研究

Preparation of PA/PDA/PVDF composite nanofiltration membrane and its application in simulated RB5 dye wastewater treatment

以聚偏氟乙烯(PVDF)超滤膜为基膜,通过多巴胺(DA)/聚乙烯亚胺(PEI)共沉积与交联剂均苯三甲酰氯(TMC)进行界面聚合组合的方法制备了聚酰胺/聚多巴胺/聚偏氟乙烯(PA/PDA/PVDF)复合纳滤膜。采用傅里叶变换红外光谱仪、原子力显微镜、场发射扫描电子显微镜对复合纳滤膜的结构、形貌进行了表征,考察了沉积时间、DA/PEI(质量浓度比)、PEI相对分子质量及DA+PEI沉积总量对复合纳滤膜微观结构与性能的影响,研究了复合纳滤膜对模拟活性黑5(RB5)染料废水的处理效果及运行稳定性。结果表明:最佳沉积时间为60min,随着PEI相对分子质量的减小,DA/PEI中PEI质量浓度的增加及DA与PEI沉积总量减小,复合纳滤膜的纯水通量增加。DA与PEI质量浓度比为1:3时,PA/PDA/PVDF复合纳滤膜最大纯水通量达到3.11L/(m^(2)·h·MPa),RB5染料废水通量为1.09L/(m^(2)·h·MPa),截留率为95.89%;DA与PEI沉积总量为4g/L时,RB5染料废水最大截留率达到99.45%,纯水通量为1.34L/(m^(2)·h·MPa),RB5染料废水通量为0.49L/(m^(2)·h·MPa)。

PA/PDA/PVDF composite nanofiltration membranes were prepared by the combination of dopamine(DA)/polyetherimide(PEI)being codeposition and crosslinking agent trimesoyl chloride(TMC)being interfacial polymerization.The PA/PDA/PVDF was characterized by Fourier transform infrared spectrometer(FT-IR),atomic force microscope(AFM),field emission scanning electron microscope(SEM)and water contact angle.At the same time,the effects of deposition time,DA/PEI mass concentration ratio,PEI molecular weight and total DA+PEI deposition on the microstructure and performance of PA/PDA/PVDF were investigated.The treatment effect and operational stability of PA/PDA/PVDF on simulated RB5 dye wastewater were discussed.The results showed that the optimal deposition time was 60min.With the decrease of the relative molecular weight of PEI,the concentration of PEI in DA/PEI increased and the total deposition amount of DA and PEI decreased,and the pure water flux of the membrane increased.When the ratio of DA to PEI was 1/3,the maximum pure water flux of PA/PDA/PVDF was 3.11L/(m^(2)·h·MPa),the flux of RB5 dye wastewater was 1.09L/(m^(2)·h·MPa),and the rejection rate was 95.89%.When the total amount of DA and PEI deposition was 4g/L,the maximum interception rate of simulated RB5 dye wastewater reached 99.45%,the pure water flux was 1.34L/(m^(2)·h·MPa),and the flux of RB5 dye wastewater was 0.49L/(m^(2)·h·MPa).