共轭聚合物复合膜处理含Ag^(+)废水的研究

Conjugated Polymer Composite Membranes for the Treatment of Ag^(+)-containing Wastewater

超滤复合膜在含Ag^(+)废水处理中表现出巨大潜力,然而超滤过程仍然受制于渗透率与截留率之间的trade-off效应。在本工作中,采用真空抽滤法将共轭聚合物聚3,4-乙烯二氧噻吩:聚苯乙烯磺酸(PEDOT:PSS)涂覆在聚醚砜(PES)基底上,用于超滤过程中截留废水中的Ag^(+)。通过分别对PEDOT:PSS分离层厚度、过滤运行压力和废水中Ag^(+)初始浓度的优化,得到PEDOT:PSS@PES复合膜的最优水通量为106.1 L m^(−2) h^(−1) bar^(−1),对5×10^(−3) g/L浓度Ag^(+)截留率可达100%,值得注意的是在超滤截留过程中Ag^(+)被还原成了Ag单质。结果表明:将共轭聚合物引入超滤膜体系,可实现高渗透通量下吸附还原Ag^(+),为含Ag^(+)废水处理提供了一种全新的思路。

Ultrafiltration composite membranes exhibit great potential for Ag^(+)-containing wastewater treatment,however,the ultrafiltration process is still limited by the trade-off effect between permeability and retention rate.In this work,the polymer poly-3,4-ethylenedioxythiophene:polystyrene sulfonic acid(PEDOT:PSS)was coated onto the polyethersulfone(PES)substrate by vacuum filtration for the retention of Ag^(+)in wastewater.By regulating the thickness of PEDOT:PSS separation layer,the operating pressure and the initial concentration of Ag^(+),the optimal water flux of 106.1 L m^(−2) h^(−1) bar^(−1) with 100%Ag^(+)retention at 5 ppm concentration is obtained for PEDOT:PSS@PES composite membrane.It is noteworthy that Ag^(+)is reduced to Ag(0)during ultrafiltration process.These results emphasize that introducing polymer into ultrafiltration membrane can absorb and reduce Ag^(+)at high permeate fluxes,which offers a new possibility for the treatment of Ag^(+)-containing wastewater.