络合-陶瓷膜耦合技术资源化处理模拟低浓度含铜废水

Resourceful treatment of artificial wastewater containing low concentration copper by complexation-ceramic membrane coupling process

以聚丙烯酸(PAA)和壳聚糖(CTS)作为络合剂,耦合孔径200 nm的陶瓷膜处理模拟低浓度含铜废水,采用ICP-MS、TOC、SEM表征与Darcy膜污染模型对处理效果和膜污染情况进行表征;对比研究不同络合剂对Cu2+截留效果与资源化回用效率的影响;并探讨对应的膜污染机理。结果表明:溶液pH通过影响聚合物络合活性位点对Cu2+截留率起决定性作用;在pH=6、P/M≥5或C/M=10的优化条件下,Cu2+截留率接近100%;PAA相对于CTS对Cu2+的络合效率更高,而CTS具备更好的抗杂质离子干扰能力;酸解、循环回用的PAA与CTS对Cu2+截留率稳定在99%以上。膜污染阻力分布计算和SEM、EDX微观表征表明,滤饼污染为膜污染主要形式,CTS更易造成不可逆的膜孔堵塞污染。

In this study,polyacrylic acid(PAA)and chitosan(CTS)were taken as the complexing agents to couple the ceramic membrane with a pore size of 200 nm for treating a type of wastewater containing lowconcentration copper.The treatment effect and membrane fouling were characterized by ICP-MS,TOC,SEM and Darcy membrane fouling model.And the effects of different complexing agents on Cu2+rejection and recycling were investigated in detail,as well as the membrane fouling mechanism.Results indicated that solution pH played a decisive role in the Cu2+rejection by affecting the complexing active sites of the polymers.Under the optimum conditions of pH=6,P/M≥5 or C/M=10,the Cu2+rejection rate could approach 100%.Compared with CTS,PAA presented a higher complexing efficiency for Cu2+,while CTS showed a better anti-interference ability against impurity ions.The recycled PAA/CTS through acid hydrolysis still maintained above 99%Cu2+rejection.Combined the membrane pollution resistance distribution calculation with SEM and EDX,the cake layer clogging was identified as the primary membrane fouling,and CTS was more likely to cause the irreversible blockage of membrane pores.