硫酸盐废水生物处理产生的硫化物处理含Pb^(2+)、Zn^(2+)的钢丝酸洗废水

Treatment of Pb^(2+),Zn^(2+)-laden acidic wire rope wastewater using sulfide from microbial sulfate reduction effluent

在一套小型搅拌反应器中,研究了碱沉淀(KOH,处理a)、碱沉淀及硫酸盐废水厌氧处理产生的硫化物出水混合(KOH+出水混合,处理b)、碱沉淀及N2吹脱硫酸盐废水厌氧处理产生的硫化物(KOH+N2吹脱,处理c),以及碱沉淀、硫酸盐废水厌氧处理产生的硫化物出水混合和N2吹脱硫化物联合(KOH+出水混合+N2吹脱,处理d)等4组处理方式对含Zn2+、Pb2+的钢丝绳酸洗废水处理效果的影响.废水pH值为0.7,Zn2+和Pb2+含量分别为450和3274 mg.L-1.结果表明,KOH+出水混合+N2吹脱的处理方式对废水有较好的处理效果,Zn2+和Pb2+的去除为氢氧化物、硫化物沉淀的共同作用结果,处理后,废水中Zn2+和Pb2+的去除率均达99.6%以上,满足污水综合排放标准(GB 8978—1996).

Four alternatives for heavy metals removal（Zn2＋,Pb2＋ and Fe2＋） in wire rope wastewater were evaluated in a bench scale mixing reactor,which were KOH neutralization（run a）,KOH neutralization and sulfide-rich anaerobic effluent treatment（run b）,KOH neutralization and sulfide precipitation by N2（run c）,KOH neutralization and sulfide-rich anaerobic effluent and N2 sparging treatment（run d）.The pH of the raw wire rope wastewater was 0.7,and the concentration of Zn2＋ and Pb2＋ were 450 and 3274 mg·L-1,respectively.It was found that the best precipitation results were obtained in run d in which the removal rates of Zn and Pb reached above 99.6%,due to the co-precipitation of hydroxide and sulfide.The treated wastewater meets the effluent discharge standard（GB 8978—1996）.