抗污染膜在电镀废水回用中的应用

Application of Antifouling Membrane in Reuse of Electroplating Wastewater

用抗污染超滤膜聚偏氟乙烯(PVDF)合金膜、高压纳滤膜(聚芳香酰胺膜)处理含Cr6+,Ni2+,Cu2+等重金属离子的电镀废水。抗污染PVDF合金超滤膜在经过三次电镀废水处理后,膜通量由4.2 L/h降为3.6 L/h,透过液的透光率大于96.3%,可去除大部分有机物。超滤透过液经过纳滤处理后,纳滤透过量由1.8 L/h降低为1.7 L/h,并且在1.5 h后基本保持不变,对Cr6+,Ni2+,Cu2+的去除率达97%以上。电镀废水经抗污染超滤膜-高压纳滤组合工艺处理,可达电镀清洗水标准,回用率达到85%。

PVDF-PES ultrafiltration membrane and high pressure nanofiltration membrane（aromatic polyamides membrane） with good antifouling property were used to treat electroplating wastewater containing Cr^6＋ , Ni^2＋ and Cu^2＋. The permeate flux of PVDF membrane decreased from 4.2 L/h to 3.6 L/h after the membrane was used for three times and the transparence at 600 nm of permeate was higher than 96.3%, which indicated that most of organic substances have been removed by PVDF membrane. After that, the ultrafiltration permeate was further treated with nanomebrane. The nanofiltration flux was declined from 1.8 L/h to 1.7 L/h and almost kept constant after 1.5 h. The removing rate of Cr^6＋ , Ni^2＋ and Cu^2＋ can reach more than 97 %. These experiments show that treated by the ultrafiltration-nanofiltration process, the electroplating wastewater can reach the level of rinse water used for electroplating, with a recycling rate of more than 85 %.