Degradation of sulfamethoxypyridazine under simulated sunlight and in the UV/Co(Ⅱ)/peroxymonosulfate system

【作者】 曾小兰； 孙小孜； 郁宁宁； 刘晶；

【机构】 信阳师范学院化学化工学院；

【摘要】 It is well known that sulfonamide antibiotics are typical environmental pollutants and their adverse effects have been reported to pose a threat to the ecological environment and human health.In this work,the direct photodegradation behavior of 11 sulfonamides （SAs） under simulated sunlight was first investigated,and the results indicated that the direct photolysis of sulfamethoxypyridazine （SMP） is the slowest among these SAs.Then the oxidation degradation of SMP in UV/Co（II）/peroxymonosulfate （PMS） system was systematically explored.Up to 95.2%removal of 0.071 mM SMP was observed after 20 minutes of reaction under the optimal condition with a molar ratio of 1:150:5 between SMP,PMS and Co（II）.The effects of some coexisting anions on degradation of SMP were investigated.It was found that Cl^-and high concentrations of CO₃^2-and HCO₃^-have a significant inhibitory effect,while HPO₄^2-has only a slight positive effect.Radical scavenger experiments indicated that hydroxyl radicals （HO^·） are prevailing active species responsible for SMP removal in UV/Co（II）/PMS system.Density functional theory （DFT）calculation results suggested that HO^·addition on the benzene ring and hydrogen abstraction are two possible pathways for SMP degradation involving HO^·and the former is easier to occur than the latter.The technology utilizing UV and Co²⁺to activate PMS is an effective approach for SMP removal in aqueous solution.更多还原

【Abstract】 It is well known that sulfonamide antibiotics are typical environmental pollutants and their adverse effects have been reported to pose a threat to the ecological environment and human health.In this work,the direct photodegradation behavior of 11 sulfonamides （SAs） under simulated sunlight was first investigated,and the results indicated that the direct photolysis of sulfamethoxypyridazine （SMP） is the slowest among these SAs.Then the oxidation degradation of SMP in UV/Co（II）/peroxymonosulfate （PMS） system was systematically explored.Up to 95.2%removal of 0.071 mM SMP was observed after 20 minutes of reaction under the optimal condition with a molar ratio of 1:150:5 between SMP,PMS and Co（II）.The effects of some coexisting anions on degradation of SMP were investigated.It was found that Cl^-and high concentrations of CO₃^2-and HCO₃^-have a significant inhibitory effect,while HPO₄^2-has only a slight positive effect.Radical scavenger experiments indicated that hydroxyl radicals （HO^·） are prevailing active species responsible for SMP removal in UV/Co（II）/PMS system.Density functional theory （DFT）calculation results suggested that HO^·addition on the benzene ring and hydrogen abstraction are two possible pathways for SMP degradation involving HO^·and the former is easier to occur than the latter.The technology utilizing UV and Co²⁺to activate PMS is an effective approach for SMP removal in aqueous solution.更多还原