沉淀-Fenton氧化预处理甲基硫菌灵废水

Study on Pretreatment of Thiophanate Methyl Wastewater by Precipitation and Fenton Regent Oxidation Method

研究沉淀-Fenton氧化对甲基硫菌灵生产废水的预处理,考察SCN^-和CODcr的去除效果。先加入Cu-SO4和Na2S2O3对SCN^-进行沉淀,考察CuSO4和Na2S2O3加入量对CODcr去除率的影响;对沉淀后水样进行Fenton氧化,通过改变pH值、H2O2浓度、Fe^2＋浓度、反应时间等得出该农药废水在常温下的最佳操作条件。实验结果表明,经过沉淀处理后的废水,pH值为4、H2O2投加量为6～7 g/L、Fe^2＋投加量为1.2～1.5 g/L,氧化时间为2～4 h,CODcr浓度从12 000 mg/L降至3 600 mg/L,总去除率达到了70%。

The experiments were pretreated the thiophanate methyl wastewater in the processes of precipitation and Fenton regent oxidation,and it investigated on degradation efficiency of SCN^- and CODcr.In the pretreatment,the optimal mass concentration of CuSO4 and NaS2O3 were deter mined on the precipitation,then the effecting factors such as H2O2,Fe^2＋,pH value,reaction time in Fenton oxidation process were discussed.The results indicated that under the condition of solution pH 4,H2O2 mass concentration 6～7 g/L,Fe^2＋ mass concentration 1.2～1.5 g/L reaction time 2～4h,the CODcr of the wastewater can decrease from 12 000 mg/L to 3 600 mg/L and the total removal rate of CODcr can reach 70%.