混凝+铁炭微电解/H2O2+活性炭处理化学清洗废水

利用混凝+铁炭微电解/H2O2+活性炭吸附法对高浓度的化学清洗废水进行联合处理,同时简单分析了反应机理及影响因素。通过实验确定了混凝最佳条件(pH=8、PAC投加量为50 mg/L、PAM投加量2 mg/L、沉淀时间40 min),铁炭微电解/H2O2最佳条件〔pH=2、(Fe+C)总投加量60 g/L、m(Fe)∶m(C)为1∶1、H2O2投加量4 mL/L、反应时间60 min〕,活性炭吸附最佳条件(吸附时间120 min、pH=6、活性炭投加量20 g/L)。结果表明,在上述最佳工艺条件下对化学清洗废水进行处理,COD去除率可达98%以上,达到国家一级排放标准(GB 8978—1996)要求。

Treatment of chemical cleaning wastewater by coagulation and iron-carbon microelectrolysis/H2O2 and activated carbon

Coagulation+iron-carbon microelectrolysis/H2O2+activated carbon process has been used for the combined treatment of high-concentration chemical cleaning wastewater.Its reaction mechanism and influencing factors are analyzed.The following optimal coagulation conditions are decided via experiments:pH is 8,PAC dosage 50 mg/L,PAM dosage 2 mg/L,and settling time 40 min.The optimal conditions for iron-carbon microelectrolysis/H2O2 are as follows:pH is 2,Fe+C total dosage 60 g/L,m(Fe)∶m(C) 1∶1,H2O2 dosage 4 mL/L,and reaction time 60 min.The optimal conditions for activated carbon adsorption are as follows:adsorption time is 120 min,pH 6,and activated carbon dosage 20 g/L.The results show that the COD removing rate can be above 98%,meeting the requirements of the first class of Integrated Wastewater Discharge Standard(GB 8978—1996) under the above optimal conditions.