Fenton试剂对久效磷的降解实验研究

The Decomposition of Monocrotophos by Fenton Reagent

初步研究了Fenton试剂对久效磷的降解,分析了H2O2浓度、温度、反应时间、pH值和Fe2+浓度这5个因素对COD去除率的影响。实验结果表明,250 mL水样中3.75×10-4mol的久效磷在Fe2+浓度为0.5 mmol/L,pH=3,H2O2浓度为0.19 mol/L,T=70℃的条件下,Fenton试剂在1 h内COD去除率为60%,3 h内COD去除率为90%,8 h内COD去除率为100%。GC-MS测试结果表明,Fenton试剂对250 mL水样中3.75×10-4mol的久效磷5 min可降解81%,30 min降解100%。根据反应速率常数拟合得出该反应符合准一级反应,反应速率常数k=0.655 6 h-1。实验还发现了Cu2+对Fenton试剂有很强的协同催化作用,体系中Cu2+浓度为1.0×10-5mol/L时,Fenton试剂在5 h内对相同水样中COD去除率为101%。

The decomposition of Monocrotophos by Fenton reagent was investigated. The influence of five factors （H2O2 concentration, temperature, reaction time, pH and Fe^2＋ concentration） on COD removal efficiency was analyzed. Under the condition of [Fe^2＋ ] = 0.5 mmol/L, pH= 3, [H2O2] = 0.19 mol/L, T = 70℃ and the amount of Monocrotophos was 3.75 × 10^-4 mol in 250 mL water samples, the removal efficiency of COD by Fenton reagent was 60% in 1 hour, 90% in 3 hours and ca. 100% in 8 hours. Analytical results of GC-MS showed that 8196 of 3.75 × 10^-4 mol Monocrotophos in 250 mL could be degradated by Fenton reagent in 5min, and 100% in 30min. Furthermore, Cu^2＋ could enhance the degradation ability of Fenton reagent on Monocrotophos. Under the condition of [ Cu^2 ＋ ] = 1.0 × 10 ^-5 mol/L, the removal efficiency of COD by Fenton reagent in 5 hours was 101%.