壳聚糖络合-陶瓷膜耦合技术处理低浓度含铜废水

Treatment of wastewater containing low concentration of Cu ion using complexation-ceramic membrane with chitosan

采用孔径为200 nm的陶瓷膜,以壳聚糖为络合剂,研究了络合-陶瓷膜耦合技术处理低浓度含铜废水过程。考察了溶液p H、壳聚糖/Cu2+质量浓度比、络合剂浓度、离子强度、操作压力及体积浓缩因子等对处理效果的影响。结果表明,壳聚糖投加量与p H是影响处理效果的关键因素,当壳聚糖/Cu2+质量浓度比≥10、p H=6时,Cu2+截留率接近100%,膜通量趋于稳定;在较高浓度外加盐(Na Cl和Na2SO4)存在时,Cu2+截留率仍可达到99%以上。将壳聚糖-铜络合物浓缩液酸化解络后通过陶瓷膜过滤分离壳聚糖和游离态的Cu2+,可实现壳聚糖的循环回用;采用回用的壳聚糖处理含铜废水时,Cu2+截留率可达到95.8%。

Complexation-ceramic membrane was used to treat the simulated wastewater with low copper concentration by the complexing agent of chitosan. The pore size of the ceramic membrane was 200 nm. The influences of the p H,mass ratio of chitosan to Cu2 +,concentration of the complexing agent,ionic strength,operating pressure and volume concentration factor on the membrane treatment process were investigated. The chitosan dosage and p H were found to be the key parameter in the process of the complexation-ceramic membrane. The results showed that the rejection rate of Cu2 +approached to 100% when the p H and mass ratio of chitosan to Cu2 +reached 6 and 10,respectively. The membrane flux was fairly high and stable. The rejection of Cu2 +was still above 99% even in the presence of Na Cl or Na2SO4. The complex concentrate of the chitosan-Cu2 +was acidified and decomplexation. The complex and Cu2 +were separated by diafiltration the ceramic membrane and the regenerated chitosan was recycled. The rejection of Cu2 +was 95. 8% when the regenerated chitosan was used to remove Cu2 +by complexation-ceramic membrane.