电混凝处理电镀综合废水

Treatment of electroplating wastewater by electrocoagulation

采用电混凝法处理酸性电镀综合废水,首先研究了不同电流密度对总氰化物、重金属和化学需氧量(COD)去除率的影响。实验结果表明,电混凝可有效去除酸性电镀综合废水中的氰化物与重金属。随着电流密度的增大,总氰化物与重金属的去除率逐渐提高。当电流密度为10 mA/cm2时,废水中残留的总氰化物、Cu2+、Ni2+、Cr6+和Zn2+的浓度分别为23.0、25.0、4.5、0.2和0.2 mg/L。为了进一步提高去除率,在电化学体系中添加H2O2,随着H2O2投量的增大,总氰化物、重金属、COD去除率不断提高。当H2O2投量为3 mL/L时,处理过废水中残留总氰化物、Cu2+、Ni2+、Cr6+、Zn2+和COD的浓度分别为0.2、2.0、3.0、1.5、0.1和220 mg/L。

Treatment of an acid electroplating wastewater was performed by an electrocoagulation process firstly. Effect of current density and treatment time on the removal of total cyanide, heavy metals and COD was in- vestigated. The results showed that total cyanide and heavy metals can be efficiently removed by the electrocoagula- tion process, which increased with the current density. At a current density of 10 mA/cm2 , the residual total cya- nide, Cu2 ＋ , Ni2＋ , Cr6 ＋ and Zn2 ＋ were 23.0, 25.0, 4.5, 0.2 and 0.2 mg/L, respectively. Removal of COD by electrocoagulation process was limited. With addition of H2O2 to electrochemical system, the removal efficiency of the total cyanide and heavy metal and COD increased. With a H2O2 dose of 3 mL/L, the residual total cyanide, Cu2＋ , Ni2＋ , Cr6＋ , Zn2＋ and COD were 0.2, 2.0, 3.0, 1.5, 0.1 and 220 mg/L, respectively.