内电解—Fenton氧化—絮凝沉淀预处理焦化废水

Pretreatment of Coking Wastewater by Internal Electrolysis-Fenton Reagent Oxidization-Flocculating Settling

采用内电解—Fenton氧化—絮凝沉淀的化学集成技术预处理焦化废水,优化了各工段的运行参数。实验结果表明：在钢铁铁屑与活性炭的体积比为1∶1的条件下,内电解工段的优化参数为进水pH 2.6~3.1、HRT=1.0 h;Fenton氧化工段的优化参数为Fe2＋加入量200 mg/L、H2O2加入量1 000 mg/L、进水pH 3.0左右、反应时间1.0 h;絮凝沉淀工段的设定参数为进水pH9.5~10.0、聚丙烯酰胺加入量1 mg/L、静置沉降0.5 h。在上述工艺条件下,该集成技术对废水的总COD去除率大于55%,处理后的废水BOD5/COD大于0.28,不添加稀释新水即可进入后续生化处理系统。该工艺占地面积小、系统结构简单、易于工业化,废水预处理成本为4~5元/t。

Coking wastewater was pretreated by the internal electrolysis-Fenton reagent oxidizationflocculating settling process. The operational parameters of each stage were optimized. When the volume ratio of scrap iron to activated carbon is 1∶1,the optimum parameters of internal electrolysis stage are as follows：influent pH 2.6-3.1,HRT 1.0 h. The optimum parameters of Fenton reagent oxidization stage are as follows：Fe2＋ dosage 200 mg/L,H2O2 dosage 1 000 mg/L,influent pH about 3.0 and reaction time 1.0 h. The set parameters of flocculating settling stage are as follows：influent pH 9.5-10.0,polyacrylamide dosage 1 mg/L and settling time 0.5 h. Under these conditions,the total COD removal rate is above 55%,and the pretreated wastewater with more than 0.28 of BOD5/COD can be biotreated without dilution.