紫外线活化过一硫酸盐工艺对水中苯脲类除草剂Chlortoluron的去除特性研究

Removal characteristics of phenylurea herbicide Chlortoluron in water by UV activated peroxymonosulfate process

为研究紫外线活化过一硫酸盐(UV/PMS)工艺对水中常见苯脲类除草剂绿麦隆(Chlortoluron)的去除特性,对比考察了UV/PMS工艺与单独UV、单独PMS对Chlortoluron的降解效果,系统探讨了降解过程中关键工艺参数如PMS投加量、UV强度、pH和常见水体背景离子(Cl^(-)、NH_(4)^(+)、HCO_(3)^(-)及SO_(4)^(2-))对Chlortoluron降解的影响,并对其相关成本效益进行了衡算分析。结果表明,UV/PMS体系中产生的强氧化性自由基包括SO-4·和HO·大大提高了Chlortoluron的去除速率,其降解过程符合拟一级动力学模型且降解速率随PMS投加量和UV强度的增加而增大;碱性pH环境比酸性pH更有利于Chlortoluron的去除;水体背景离子Cl^(-)和NH_(4)^(+)显著抑制了Chlortoluron的降解,HCO_(3)^(-)则表现出促进效应,而SO_(4)^(2-)的影响并不显著。通过能耗评估分析可知,当PMS投加量为160μmol/L、UV强度为2.43 mW/cm 2时的单位电能消耗量最低,UV/PMS工艺的成本效益最大。研究结果可为水处理中UV/PMS工艺对Chlortoluron的去除提供相关理论参考和技术支持。

To investigate the removal properties of Chlortoluron,a common phenylurea herbicide in water,Chlortoluron was affected by UV activated peroxymonosulfate(UV/PMS)process,and the degradation effect of Chlortoluron was compared with direct UV and direct PMS.The influences of key process parameters such as PMS dosage,UV intensity,pH,and common background ions(Cl^(-),NH_(4)^(+),HCO_(3)^(-)and SO_(4)^(2-))on Chlortoluron degradation were systematically explored,and the relevant cost-effectiveness was analyzed.The results showed that the active radicals including SO-4·and HO·produced in UV/PMS system greatly improved the removal rate of Chlortoluron,the degradation process followed the pseudo-first-order kinetic model,and the degradation rate increased with the increase of PMS dosage and UV intensity.Alkaline pH environment was more conducive to Chlortoluron removal than acidic pH environment.Chlortoluron degradation was significantly inhibited by background ions Cl^(-)and NH_(4)^(+),while Chlortoluron degradation was promoted by HCO_(3)^(-),but not by SO_(4)^(2-).According to energy consumption evaluation and analysis,electrical energy per order was the lowest when PMS dosage was 160μmol/L and UV intensity was 2.43 mW/cm^(2),and the cost-effectiveness of UV/PMS process was the highest.This study can provide theoretical reference and technical support for Chlortoluron removal by UV/PMS process in water treatment.