胶团强化超滤–纳滤联用技术处理尾矿土壤洗脱液的工艺研究
Process Research on Treatment of Tailings Soil Eluent by the Combined Technology of Micellar-Enhanced Ultrafiltration-Nanofiltration

用螯合性表面活性剂淋洗重金属污染土壤，重金属的去除效果显著。如何处理这类洗脱液以达到国家排放标准是螯合性表面活性剂能否大规模用于修复重金属污染土壤的关键因素之一。本文用胶团强化超滤–纳滤联用技术研究含螯合性表面活性剂的尾矿土壤洗脱液的净化工艺，着重研究了跨膜压力和进料液pH值对超滤(纳滤)效果影响。结果表明，在较高跨膜压力(跨膜压力大于0.2 MPa)下，超滤(纳滤)渗出液中重金属离子含量和COD值比在低跨膜压力下低；在较低的进料液pH值下(pH < 10.0)的渗出液中重金属离子含量和COD值比在较高进料液pH值下小。在实验条件下，尾矿土壤洗脱液经超滤、纳滤后的出水的重金属离子(Cu²⁺、Zn²⁺、Cd²⁺、Pb²⁺含量)、COD、总氮、总磷及氨氮值可以达到GB3838-2002 V类水质的要求和GB18918-2002的一级A标准。
Leaching heavy metal contaminated soil with chelating surfactant has a significant heavy metal removal effect. How to treat this kind of eluent to meet the national discharge standard is one of the key factors in whether chelating surfactants can be used to restore heavy metal contaminated soil on a large scale. In this paper, the purification process of tailings soil eluent containing chelating surfactant was studied by the combined technology of Micellar-Enhanced Ultrafiltration (MEUF) and Nanofiltration (NF), and emphatically the influence of transmembrane pressure and pH values of feed solution on ultrafiltration (nanofiltration) were discussed. The results showed that under higher transmembrane pressure (transmembrane pressure is greater than 0.2 MPa), the content of heavy metal ions and COD values in ultrafiltration (nanofiltration) permeate solution is lower than that under low transmembrane pressure, and the content of heavy metal ions and COD values in the exudate at lower pH values (pH < 10.0) of feed solution is smaller than that at higher feed pH values of feed solution. Under the experimental conditions, the content of heavy metal ions (Cu²⁺, Zn²⁺, Cd²⁺, Pb²⁺), COD, total nitrogen, total phosphorus and ammonia nitrogen in the effluent of tailings soil eluent after ultrafiltration and nanofiltration can meet the requirements of GB3838-2002 Class V water quality and the First-Class A standard of GB18918-2002.