摘要
以有机磷农药草甘膦作为目标污染物,进行了臭氧氧化试验.研究了不同臭氧投量、草甘膦初始浓度、初始pH对臭氧氧化去除草甘膦的影响,并对降解途径进行了探究.实验结果表明:臭氧投量越大,草甘膦初始浓度越低,臭氧氧化草甘膦的反应速率越快;不同pH条件下,碱性体系中草甘膦的去除速率最快,中性次之,酸性体系中草甘膦的去除速率最慢;臭氧氧化草甘膦的矿化程度较高,反应30min时,TOC的去除率为77.65%,反应60min时,TOC的去除率为93.52%;臭氧氧化过程遵循羟基自由基的反应机理;反应产物氨甲基磷酸(AMPA)先逐渐积累,然后逐渐降低,磷酸根离子从反应初期就开始逐渐积累,反应中间产物主要有羟基乙酸(Glycolicacid)、氨基乙酸(Glycine)、AMPA和H3PO4等.
In this work,the influence of pH,ozone dosage and initial concentration of glyphosate on the degradation of glyphosate by ozone was investigated in detail.The pathway for the glyphosate degradation by ozone is also discussed.The results showed that the degradation rate of glyphosate by ozone increased with increasing ozone dosage,and decreased with increasing initial concentration of glyphosate.Under different pH conditions,the removal rate of glyphosate decreased in the following order：basic neutral acidic.The degradation of glyphosate by ozone was found to be accomplished by hydroxyl radicals.Intermediates of glycolic,Glycine,AMPA,and orthophosphoric acid were identified during the ozonation of glyphosate.AMPA accumulated in the initial reaction time and decreased subsequently.Phosphate ions accumulated as reaction time increased.
出处
《环境科学学报》
CAS
CSCD
北大核心
2011年第8期1647-1652,共6页
Acta Scientiae Circumstantiae
基金
国家自然科学基金(No.51008292)
环境模拟与污染控制国家重点联合实验室基金(No.09Y05ESPCR)
国家水体污染控制与治理科技重大专项(No.2009ZX07419-005-02)~~
关键词
草甘膦
臭氧氧化
有机磷农药
降解
glyphosate
ozonization
organophosphorus pesticides
degradation
