不同氧化剂对土壤中有机氯农药γ-HCH降解效果的影响  

Effects of Different Oxidants on Degradation of Organochlorine Pesticide γ-HCH in Soil

作　　者：项文霞 李义连[2] 李钊 陈金国 XIANG Wen-xia;LI Yi-lian;LI Zhao;CHEN Jin-guo(Third Geological Brigade of Hubei Geological Bureau,Huanggang 438000,China;School of Environmental Studies,China University of Geosciences(Wuhan),Wuhan 430074,China;Huangzhou Natural Resources and Planning Burea,Huanggang 438000,China)

机构地区：[1]湖北省地质局第三地质大队,湖北黄冈438000 [2]中国地质大学(武汉)环境学院,湖北武汉430074 [3]黄州区自然资源和规划局,湖北黄冈438000

出　　处：《化学试剂》2022年第4期577-583,共7页Chemical Reagents

摘　　要：有机氯农药γ-HCH杀虫活性强、化学性质稳定,在环境中不易降解,残留期长,对生态环境和人体危害严重。通过加速溶剂萃取法联合气相色谱法,研究了Fenton试剂、热活化的Na_(2)S_(2)O_(8)对土壤中有机氯农药γ-HCH的降解效果。结果表明,Fenton试剂和Na_(2)S_(2)O_(8)在氧化降解γ-HCH方面都表现出很高的活性。当水土质量比为2.5∶1(g/g),反应温度为25℃,Fe^(2+)和H_(2)O_(2)投加量分别为0.2 mmol和10 mmol时,γ-HCH去除率为88%;当水土质量比为2.5∶1(g/g),反应温度为50℃,Na_(2)S_(2)O_(8)投加量为5 mmol时,γ-HCH去除率为91.78%。使用Fenton试剂和Na_(2)S_(2)O_(8)分别作为氧化剂对γ-HCH的去除均符合准一级反应动力学模型,其反应速率和去除率与水土质量比、反应温度、氧化剂投入量等因素有关。在优化后的反应条件下,使用Na_(2)S_(2)O_(8)氧化降解γ-HCH的反应速率常数和反应半衰期分别为0.003 min^(-1)和3.85 h;相较于Fenton试剂,其反应速率常数提高了约50%,反应半衰期缩短了约35%。Organochlorine pesticide γ-hexachlorocyclohexane(γ-HCH) has strong insecticidal activity and is difficult to be degraded in the environment due to its stable chemical properties and long residual period.γ-HCH is seriously harmful to the ecological environment and human.Through an accelerated solvent extraction coupled with gas chromatography method,the effect of Fenton reagent and thermally activated sodium persulfate on γ-HCH degradation in soil was studied.The results indicated that Fenton reagent and sodium persulfate displayed high reactivity to the oxidative degradation of γ-HCH.When the amount of Fe^(2+) and H_(2)O_(2) were 0.2 mmol and 10 mmol,respectively,the removal rate of γ-HCH was 88% at 25 ℃ and 2.5 g/g of water-soil ratio.When the dosage of sodium persulfate was 5 mmol,the removal rate of γ-HCH was 91.78% at 50 ℃ and 2.5 g/g of water-soil ratio.The degradation reaction of γ-HCH using Fenton reagent and sodium persulfate as oxidants conformed to a pseudo-first order kinetic model.The reaction rate and removal rate were affected by many factors,such as water-soil ratio,reaction temperature and the amount of oxidants.Under optimized reaction conditions,the reaction rate constant and reaction half-life time of γ-HCH degradation using sodium persulfate were 0.003 min^(-1) and 3.85 h,respectively.Compared with Fenton reagent,the reaction rate constant was increased by about 50%,and the reaction half-life time was shortened by about 35%.

关 键 词：FENTON试剂 Na_(2)S_(2)O_(8) Γ-HCH 脱氯 氧化降解 反应动力学 

分 类 号：X53[环境科学与工程—环境工程]