兽药磺胺二甲嘧啶在土壤中的生态行为

通过室内培养和土壤薄层层析等实验方法，研究了磺胺二甲嘧啶对土壤微生物的毒性及其在土壤中的降解、迁移特性。结果显示：在土壤磺胺二甲嘧啶浓度为1mg kg^-1时，土壤中细菌和真菌数量明显减少（p〈0．05），但随时间延长，该抑制作用变缓；磺胺二甲嘧啶在土壤中降解缓慢，持留时间久，在灭菌土和未灭菌土中的半衰期分别为223．9d和102．4d，并容易在土壤中迁移和渗漏，迁移系数R大于0．7，迁移和渗漏速度受介质pH的影响，在非中性环境下，移动和渗漏能力增强。表明磺胺二甲嘧啶是一种在土壤中不易被降解、容易迁移和渗漏到水体、对土壤微生物和水体产生危害的新型污染源。

ECOTOXICOLOGY AND ECOLOGICAL BEHAVIOR OF SULFAMETHAZINE IN SOIL

Ecotoxicology of sulfamethazine on soil microbial activity and its degradation and transfer in the soil were investigated.Results show that 1 mg kg-1 concentration of sulfamethazine in soil resulted in an apparent decrease in populations of bacteria and fungi(p<0.05).Moreover,sulfamethazine was observed hardly degrading in soil,with a half life of 223.9 d and 102.4 d in sterilized and unsterilized soil respectively.And the thin-layer chromatogram and leaching test indicated that sulfamethazine was liable to transfer and get leached,with Rf being more than 0.7,and its transfer and leaching rates were subject to the impact of pH and increased in acidic and alkaline developing agents,suggesting that sulfamethazine,as veterinary antibiotic,is a new environmental contaminant strong in ecotoxicology and mobility,low in degradation rate in soil,thus posing a potential pollution risk to water bodies.