改进硫化物沉淀法处理氨羧配位剂电镀镉废水的研究

Treatment of Electroplating Wastewater Containing Cadmium by Ammonia Complexing Agent by Improved Sulfide Precipitation Method

采用Na_2S-Al_2(SO_4)_3-PAM体系直接处理氨羧配位剂电镀镉废水,并考察了废水初始pH值、Na_2S的投加量、Al_2(SO_4)_3·18H_2O的投加量及反应时间对处理效果的影响。结果表明:废水初始pH值为7、Na_2S的投加量为5mL/L,在常温下搅拌反应20min;再投加絮凝剂Al_2(SO_4)_3·18H_2O 8mL/L及PAM 3mL/L,继续搅拌反应5min后静置15min。上清液中残余Cd^(2+)的质量浓度为0.03mg/L,达到《电镀污染物排放标准》(GB 21900—2008)中规定的不大于0.05mg/L的要求,同时Cd^(2+)的去除率达到99.9%。

Na2 S-Al2 （SO4）3-PAM system is adopted to deal electroplating wastewater containing cadmium by ammonia complexing agent directly. The effects of initial pH value of wastewater, the dosage of Na2S, the dosage of Al2 （SO4）3 · 18H2O and reaction time on the treatment efficiency were studied. Experimental results show that at pH = 7, when the dosage of Na2 S is 5 mL/L, after stirring reaction 20 min at room temperature, 8 mL/L Al2 （SO4）3 · 18H2O and 3 mL/L PAM were added, continue stirring reaction 5 min, and then put it aside for 15 min. The mass concentration of residual Cd2＋ in the supernatant was 0. 03 mg/L, which reaches the requirement of no more than 0. 05 mg/L in GB 21900--2008, and the removal rate of Cd2＋ reached 99.9%.