混凝—纳滤法处理印染漂白废水

Treatment of Bleaching Wastewater in Dyeing and Printing Plant by Coagulation-Nanofiltration

采用混凝—纳滤法处理印染漂白废水,考察了混凝剂种类和膜操作条件对出水COD、浊度的影响。实验结果表明:混凝以硫酸为混凝剂、混凝pH为1.0;纳滤运行压力为1.86 MPa、运行温度为20℃、进水pH为7左右、浓缩倍数为1时,纳滤出水COD降至30 mg/L左右,总COD去除率为95.4%;浊度为0,总浊度去除率为100%。出水水质满足工业用水回用标准。

The bleaching wastewater in a dyeing and Printing plant was treated by coagulation-nanofiltration process. The effects of coagulants and operation conditions on the effluent COD and turbidity were studied. The optimum conditions for coagulation are as follows： sulfuric acid used as coagulant, coagulation pH 1.0. The optimum conditions for nanofiltration are as follows： running pressure 1.86 MPa, running temperature 20 ℃, influent pH about 7, concentration multiple 1. Under these conditions, the COD of nanofiltration effluent is decreased to about 30 mg/L with 95.4% of total COD removal rate, the effluent turbidity is 0 with 100% of total turbidity removal rate. The quality of the effluent can meet the industrial water reuse standards.