加载絮凝—超滤—反渗透组合工艺处理PCB电镀废水

Treatment of PCB electroplating wastewater by combination process of loading flocculation-ultrafiltration-reverse osmosis

采用加载絮凝—超滤—反渗透组合工艺处理含大量重金属离子的印制电路板(PCB)电镀废水。考察了絮凝污泥回流比和水力条件对加载絮凝效果的影响,确定了最佳工艺参数:在加碱沉淀pH 10.5、混凝pH 9.0、PAC投加量10 mg/L、PAM投加量1.0 mg/L的条件下,污泥回流比为47%,加碱沉淀、混凝、絮凝的搅拌转速分别为250,150,50 r/min,搅拌时间分别为6,8,4 min。中试结果表明:经加载絮凝预处理后,总铜、总镍和浊度的平均去除率分别为99.4%、99.3%和93.1%;预处理出水经超滤—反渗透系统处理后,出水水质全部达标。

The printed circuit board ( PCB ) electroplating wastewater with large amount of heavy metal ions was treated by combination process of loading flocculation-ultrafiltration-reverse osmosis. The effect of sludge backflow ratio and hydraulic conditions on loading flocculation was investigated. The optimal process parameters were determined : Under the conditions of alkali precipitating pH 10.5 , coagulating pH 9.0 , PAC amount 10 mg/L and PAM amount 1.0 mg/L , the sludge backflow ratio was 47 %, the mixing speed of alkali precipitating , coagulation , flucculation was 250 , 150 , 50 r/min , and the mixing time was 6 , 8 , 4 min , respectively. The pilot test results showed that : After pretreatment by loading flocculation , the average removal rate of total Cu^2+, total Ni^2+ and turbidity was 99.4 %, 99.3 % and 93.1 %, respectively;After UF-RO treatment , all the effluent quality indexes met the discharge standard。