柠檬酸-Fe(Ⅱ)/K2S2O8对敌草隆降解的研究  

DEGRADATION OF DIURON BY CITRIC ACID-IRON(Ⅱ) CATALYZED POTASSIUM PERSULFATE

作　　者：郑伟[1] 张金凤[1] 王联红[1] 孔令仁[1] 杨曦[1] 

机构地区：[1]南京大学环境学院,污染控制与资源化研究国家重点实验室,南京210093

出　　处：《环境化学》2008年第1期19-22,共4页Environmental Chemistry

基　　金：国家自然科学基金项目(No.50578074,20207004).

摘　　要：研究了初始pH值为3.0时敌草隆在柠檬酸-Fe(Ⅱ)/K2S2O8体系中的降解行为.结果显示,0.1mmol.l-1敌草隆的最佳降解条件为:[K2S2O8]=2.0mmol.l-1,[Fe(Ⅱ)]=1.0mmol.l-1,[CA]=0.5mmol.l-1.在该条件下,敌草隆的降解符合一级反应动力学,半衰期为30.5m in.此外,采用分子探针法鉴定了体系中产生的硫酸根自由基和羟基自由基.并采用液-质联用技术鉴定了敌草隆在柠檬酸-Fe(Ⅱ)/K2S2O8体系中的降解产物,探讨敌草隆在柠檬酸-Fe(Ⅱ)/K2S2O8体系中可能的降解机理.The degradation of Diuron（3-（3,4-dichlorophenyl）-1,1-dimethylurea）in aqueous solution by citric acid-iron（Ⅱ）catalyzed potassium persulfate was investigated,as well as the effects of individual initial concentration of K2S2O8,Fe（Ⅱ）and citric acid.The optimized dose of K2S2O8,Fe（Ⅱ）and citric acid were 2.0 mmol·l^-1,1.0mmol·l^-1 and 0.5mmol·l^-1 respectively for 0.1mmol·l^-1 Diuron solution（initial pH3.0）.Under this condition,the degradation of diuron followed a first-order kinetics.Hydroxyl radical and sulfate radical were determined in the citric acid-iron（Ⅱ）catalyzed potassium persulfate system of diuron with molecular probes（ethanol and tert-butanol）.The degradation products of diuron in the citric acid-iron（Ⅱ）catalyzed potassium persulfate system were identified with LC/MS methods.The possible degradation pathways of diuron were discussed.

关 键 词：敌草隆 Fe(Ⅱ) 过硫酸钾 柠檬酸 硫酸根自由基 羟基自由基 

分 类 号：X50[环境科学与工程—环境工程]