中文摘要：

微囊藻毒素（MCs）是蓝藻水华污染产生的一类生物毒素,通过灌溉、施肥等途径进入农田土壤,对农产品质量和地下水安全造成危害,进而影响人体健康.其中MC-LR是毒性较大、检出较普遍的藻毒素之一.本文通过模拟实验,研究了MC-LR在土壤中的生物降解行为及其影响因素.结果表明,MC-LR为易降解有机污染物,土壤理化性质可影响其在土壤中的降解行为,呈现土壤pH越低、阳离子交换量越大,MC-LR老化系数越大,降解越慢的特征.然而,初始浓度对MC-LR的降解没有影响.微生物降解是土壤中MC-LR降解的主要途径,温度、含水率等环境因素对MC-LR降解的影响主要在于改变土壤中降解微生物的活性.研究结果为评估土壤中MC-LR的生态风险提供了依据.

英文摘要：

Microcystins（ MCs） is a biotoxin produced by aquatic cyanobacteria bloom. It can be transferred into the soil-plant system via irrigation or fertilization. Microcystin-LR（ MC-LR） is one of MCs commonly studied for its toxicity and high detection frequent. In the present study,degradation of MC-LR in soils was investigated by simulation experiment. Results showed that MC-LR was an easily degradable organic pollutant. Degradation of MC-LR was affected by the soil physiochemical property and the degradation increased with the increasing pH value and decreasing cation exchange capacity.However,degradation of MC-LR was hardly affected by the initial concentration. Microbes played a major role in the degradation of MC-LR in soil. The influences of environmental factors including temperature and soil moisture on the degradation of MC-LR occurred by changing soil microbial activity. The results provided useful information for evaluating the ecological risks of MC-LR in soil.