Effects of environmental factors on sulfamethoxazole photodegradation under simulated sunlight irradiation: Kinetics and mechanism  

作　　者：Junfeng Niu Lilan Zhang Yang Li Jinbo Zhao Sidan Lv Keqing Xiao 

机构地区：[1]State Key Laboratory of Water Environment Simulation,School of Environment,Beijing Normal University

出　　处：《Journal of Environmental Sciences》2013年第6期1098-1106,共9页环境科学学报（英文版）

基　　金：supported by the National Basic Research Program (973) of China (No. 2010CB429003);the National Natural Science Foundation of China (No.21077010);the Fok Ying-Tong Education Foundation,China (No. 121077)

摘　　要：To advance the knowledge of the environmental fate of sulfamethoxazole （SMX）, we systematically investigated the effects of natural water constituents and synthetic substances （i.e., TiO2 nanoparticles （nTiO2） and Ti-doped ^-Bi203 （NTB）） on the photodegradation kinetics of SMX under xenon lamp irradiation. The photolysis of SMX in aqueous solution followed first-order kinetics. Our results showed that higher concentrations of SMX, fulvic acid, suspended sediments, NTB and higher pH value decreased the photodegradation rates of SMX, whereas H202 improved the SMX photodegradation. TiO2 nanoparticles had a dual effect on pbotodegradation due to their photocatalytic activity and photoabsorption of photons. No intermediates more toxic toward Vibrio fischeri than SMX were produced after direct photolysis and photocatalytic degradation for 3 hr. The photolysis of SMX involved three pathways： hydroxylation, cleavage of the sulfonamide bond, and fragmentation of the isoxazole ring. This study lays the groundwork for a better understanding of the environmental fate of SMX.To advance the knowledge of the environmental fate of sulfamethoxazole （SMX）, we systematically investigated the effects of natural water constituents and synthetic substances （i.e., TiO2 nanoparticles （nTiO2） and Ti-doped ^-Bi203 （NTB）） on the photodegradation kinetics of SMX under xenon lamp irradiation. The photolysis of SMX in aqueous solution followed first-order kinetics. Our results showed that higher concentrations of SMX, fulvic acid, suspended sediments, NTB and higher pH value decreased the photodegradation rates of SMX, whereas H202 improved the SMX photodegradation. TiO2 nanoparticles had a dual effect on pbotodegradation due to their photocatalytic activity and photoabsorption of photons. No intermediates more toxic toward Vibrio fischeri than SMX were produced after direct photolysis and photocatalytic degradation for 3 hr. The photolysis of SMX involved three pathways： hydroxylation, cleavage of the sulfonamide bond, and fragmentation of the isoxazole ring. This study lays the groundwork for a better understanding of the environmental fate of SMX.

关 键 词：PHOTODEGRADATION SULFAMETHOXAZOLE environmental factors TOXICITY 

分 类 号：X13[环境科学与工程—环境科学]