臭氧氧化降解除草剂扑草净实验研究

Degradation of prometryn by ozone oxidation

利用臭氧氧化去除水中三嗪类除草剂扑草净,探讨不同反应条件对扑草净降解效率的影响.结果表明,随着pH值和温度的增加,扑草净去除率先增大后减小,存在一个最佳pH值8.17和最佳反应温度28℃.随臭氧投量的增加,扑草净降解速率提高;扑草净初始质量浓度增加,扑草净降解效率减小.低质量浓度腐殖酸(0.2 mg/L)可以促进扑草净的降解,但是高质量浓度的腐殖酸对扑草净去除有抑制作用,当腐植酸投量为2.5 mg/L、5 mg/L时,扑草净去除率分别从不投加腐殖酸时的87.1%降低至83.94%、74.58%.碳酸氢根对扑草净去除有抑制作用,且随着碳酸氢根质量浓度的增大,抑制作用越明显,投加碳酸氢根质量浓度为2.0 mmol/L时,扑草净的去除率从不投加碳酸氢根时的87.1%降低至64.0%.

Adopting ozonization to study the removal of the wastewater containing prometryn,the paper explores the influence of different reaction conditions on the degradation efficiency of prometryn.The results showed that,the degradation rate of prometryn increased at first and then decreased with the increasing pH and temperature.There exist the optimum values of pH（8.17） and temperature（28℃） on degradation of prometryn.The degradation rate of prometryn increased as ozone concentration increased,but descended as its initial concentration increased.The removal of prometryn descended when the concentration（0.2mg/L）of humic acid is low,whereas the high concentration of humic acid has an inhibiting effect on removal of prometryn.When humic acid dosage was 2.5mg/L and 5mg/L,the degradation rate of prometryn descended from 87.1% to 83.94% and 74.58%.Bicarbonate had inhibiting effect on removal of prometryn,and with the bicarbonate concentration increasing,the inhibition was more obvious,when bicarbonate dosage was 2.0mmol/L,the degradation rate of prometryn descended from 87.1% to 64.0%.