基于单反应和多反应评估水产养殖中抗生素的环境行为

An Assessment of Environmental Behaviour of Antibiotics in Aquaculture Based on Single Reaction and Multi Reaction

通过控制实验分别研究了磺胺甲基嘧啶(SM1)、恩诺沙星(ENR)、金霉素(CTC)和甲氧苄啶(TMP)在水产养殖水体中的水解、光解、生物降解和综合降解过程以及在水-沉积物系统中的迁移与分布规律。结果表明:养殖水体中,SM1、ENR的水解半衰期较长,CTC较短,TMP几乎不发生水解;光解和生物降解的半衰期明显低于水解;4种抗生素的综合降解速率比任何一个单一反应的降解速率都要快。在水-沉积物系统,水相中4种抗生素均在0~7d内快速衰减;平衡时的吸附系数(Kd),ENR>CTC>SM1和TMP;沉积物中CTC和TMP的降解半衰期长,SM1的半衰期较短,ENR的半衰期在不同的沉积物中差异较大,沉积物中抗生素的持久性普遍高于水中。

The hydrolysis,photolysis,biodegradation and comprehensive degradation processes of sulphamethazine(SM1),enrofloxacin(ENR),chlorotetracycline(CTC)and trimethoprim(TMP)in aquaculture water,as well as their migration and distribution in water-sediment system were studied by control experiments.The results have showed that in aquaculture water,the hydrolysis half-lives of SM1 and ENR are longer than that of CTC whilst TMP being hardly hydrolysed.The half-life of photolysis and biodegradation is significantly lower than that of hydrolysis.The comprehensive degradation rate of those four antibiotics is faster than anyone of their single reaction degradation.In the water-sediment system,the four antibiotics in aqueous phase all decay rapidly within seven days,and their adsorption coefficients(Kd)shows an order of ENR>CTC>SM1 and TMP at equilibrium.In sediment,the degradation half-lives are longer for CTC and TMP than for SM1,and there are great differences for ENR in various sediment.The persistence of antibiotics in sediment is generally higher than that in water.