乙二胺四乙酸钠对纳滤铜去除效能的影响

Influence Studies of EDTA on Removal of Copper Ions by Nanofiltration

以乙二胺四乙酸钠(EDTA)为络合剂,选取含有重金属铜的土壤酸性沥出液为研究对象,探索络合纳滤工艺对Cu^(2+)去除率和膜通量的强化效果,并研究了p H、EDTA含量和压力对络合纳滤过程的影响,同时采用正交实验设计络合纳滤工艺条件进行了优化。结果表明,优化操作条件为:温度20℃,压力1.8 MPa,p H为4.0,c(EDTA):c(Cu)为1:6。EDTA可以明显地增强纳滤膜对Cu^(2+)的截留率和膜通量,与不添加EDTA相比,Cu^(2+)截留率从94.6%增至99.7%,膜通量从62 L/(m2·h)增至160 L/(m^2·h)。

Ethylenediamine tetraacetic acid disodium salt（EDTA） was chosen as the complexing agent to study the enhanced effects of nanofiltration for the removal of copper from soil acidic leachate. The effects of p H, content of EDTA and applied pressure on copper ions rejection were examined in complexation nanofiltration, and simultaneously its process conditions were optimized by orthogonal experimental design. The experiment indicated that the optimal conditions should be： temperature was 20 ℃, the pressure was 1.8 MPa,the p H was 4.0, the ratio of c（EDTA）：c（Cu） was1：6. The rejection to Cu2＋and permeability could be enhanced obviously by the EDTA, and the rejection to Cu2＋was increased from 94.6% to 99.7%, the flux increased from62 L/（m2·h） to 160 L/（m2·h） when EDTA was feed.