用丙烯酸-马来酸共聚物(PMA-100)作络合剂采用络合-超滤技术处理模拟含镉(Cd2+)废水,研究聚合物/金属离子质量比(P/M)、溶液pH、盐浓度、操作压力(TMP)和运行时间等对镉离子截留率和膜通量的影响。结果表明:在一定P/M下,pH在3~7范围内,适当提高溶液pH值有利于镉离子的截留;在一定pH条件下,镉离子截留率R随P/M的增加而增加;当pH=5.8、P/M=6时,镉离子的截留率可达99%以上;溶液pH值在3~7范围内时,NaCl和Na2SO4的存在使镉离子的截留率有所降低。当溶液pH〈5.8时,酒石酸钾钠的存在使Cd2+的截留率有所下降。
The treatment of wastewater containing cadmium ions by complexation-ultrafiltration was studied using copolymer of acrylic acid-maleic acid as the complexing agent.The effects of mass ratio of polymer to metal(P/M),pH,concentration of the added salt,transmembrane pressure(TMP) and processing time on retention(R) of cadmium ions and permeate fluxes were investigated.The results indicate that the retention of cadmium ions depends strongly on pH and increases with the increase of pH at a certain P/M,and increases with the increase of P/M value under a certain pH value.The retention can reach over 99% at pH of 5.8 and P/M of 6.The retention of cadmium ion decreases slightly with the increase of sodium chloride and sodium sulfate concentration at pH of 3-7,and decreases with the addition of seignette salt at pH less than 5.8.