摘要
研究了CoTPPS4/Na2 S2 O8-H2 O2体系(CoTPPS4:meso-四-(4-磺基苯基)卟啉钴)对农药敌敌畏(DDVP)催化氧化降解效果,探讨了氧化剂种类及比例、催化剂用量、农药初始浓度、pH值及反应温度等因素对催化降解速度的影响,并在优化条件下对降解反应的动力学进行了考察。结果表明,随着催化剂用量增加、初始农药浓度的降低、pH值升高(pH值为5～9)和温度的上升,DDVP降解率增加。室温时,在pH=9缓冲溶液中,农药初始浓度为1.015×10-4 mol/L、CoTPPS4加入量为2.4×10-3 g时,5 mL 0.050 mol/L Na2 S2 O8-H2O2(体积比4∶1)混合氧化剂存在条件下,7 h后DDVP农药降解率可达72.8%,反应速率常数为0.190 h-1。降解反应动力学研究表明,CoTPPS4催化混合氧化剂降解农药DDVP为表观一级反应,反应表观活化能Ea为5.052 kJ/mol。
The degradation efficiency of dichlorvos（DDVP） pesticide was conducted using a mixture of hydrogen peroxide and sodium persulfate,catalyzed by cobalt meso-tetrakis（4-sulfonatophenyl）porphyrin（CoTPPS4）.Influencing factors on degradation ratio of dichlorvos were discussed,such as oxidant species,mixing ratio between oxidants,amount of additional catalyst,initial concentration of pesticide,pH value and temperature.Reaction kinetics of degradation reaction under optimized conditions was also studied.The degradation rate increased with the increases of catalyst dosage,pH（5～9） and reaction temperature as well as the decrease of initial concentration of pesticide.The results indicated that the degradation rate of 1.015 mol/L DDVP can reach to 72.8% after 7 h,when an additional volume of mixed oxidants of Na2S2O8 and H2O2（4/1,volume ratio） with 0.050 mol/L is 5 mL,the catalyst dosage is 2.4×10-3 g at pH=9,rate constant is 0.190 h-1.Kinetic studies suggest that the catalyzed oxidative degradation of dichlorvos is a pseudo-first-order reaction with the activation energy Ea of 5.052 kJ/mol.
出处
《应用化学》
CAS
CSCD
北大核心
2011年第9期1035-1040,共6页
Chinese Journal of Applied Chemistry
基金
教育部大学生创新性实验计划(DCSJ08-013)
关键词
过硫酸钠
催化降解
敌敌畏
活化能
sodium persulfate
catalytic degradation
dichlorvos
activation energy
