Na_2S沉淀与混凝沉淀组合工艺处理电镀废水的研究

Study on Treatment of Electroplating Wastewater by the Combination of Na_2S Precipitation and Coagulation Sedimentation

采用Na_2S 沉淀与混凝沉淀组合工艺处理电镀废水中的Cu^(2+)与COD,并研究了各工艺条件对电镀废水处理效果的影响。Na_2S 沉淀工艺的最佳条件为:Na_2S 的投加量100mg/L,初始pH值7.5,反应时间15min。混凝沉淀工艺的最佳条件为:混凝pH值7.5,混凝剂PAC的投加量8.0mg/L,助凝剂PAM的投加量8.0mg/L,混凝时间6min,沉降时间60min。在最佳处理工艺条件下,出水中Cu^(2+)的质量浓度为0.43mg/L,COD的质量浓度为41.27mg/L,能够达到电镀废水排放标准。

Cu2＋ and COD in electroplating wastewater were treated by the combination of Na2S precipitation and coagulation sedimentation. The effects of various technological conditions on the treatment effect of electroplating wastewater were studied. Results showed that the optimum technological conditions for Na2 S precipitation were Na2 S dosage 100 mg/L, initial pH value 7.5, reaction time 15 min, and the optimum technological conditions for coagulation sedimentation were coagulation pH value 7.5, PAC dosage 8.0 mg/L, PAM dosage 8.0 mg/L, coagulation time 6 min, sedimentation time 60 min. Under the optimum technological conditions, the mass concentration of Cu2＋ and COD in the treated wastewater were 0. 43 mg/L and 41. 27 mg/L respectively, which can meet the electroplating wastewater discharge standards.