天然水体中微囊藻毒素归宿的初步研究

PRIMARY RESEARCH OF THE MICROCYSTIN'S FATE IN NATURAL AQUATIC SYSTEM

微囊藻毒素是有毒蓝藻释放的肝毒性代谢物,对环境和人们健康具有潜在危害,成为各国普遍关注的热点,并已列入我国地表水环境质量特定检测项目。在暴发严重蓝藻水华的滇池水环境治理工程中,对水华污染水体中微囊藻毒素的含量进行了全年监测,结果表明水样中微囊藻毒素含量的变化范围为0.17～0.82μg/L,比水体中蓝藻生物量的藻毒素含量低了至少一个数量级。为研究水体中藻毒素的归宿,通过有关微囊藻毒素的吸附、光降解、微生物降解等一系列现场和实验室研究,结果表明光降解是滇池水体中微囊藻毒素浓度降低的主要途径,同时微生物降解、生物积累和颗粒物吸附也是水体中微囊藻毒素浓度降低的因素。探讨了蓝藻水华污染水体的藻毒素归宿途径,并提出了有待研究的问题。

Mierocystins are hepatotoxin released by harmful toxic cyanobacterial bloom, are the potential risk factor of natural environment and human health. MC-LR has been listed as the special examining item in the newly published Environmental Quality Standard for the surface water. The paper investigated the seasonal variation of microcystin concentrations in lake Dianchi, where serious bloom has occurred in recent years. The concentration of microcystins has a range of 0.17-0.82 μg/L, which is far less than the amount in the cyanobacteria mass. The fate of microcystin in the lake was put forward on the base of absorption, photodegradation, and biodegradation experiments in site or in the laboratory. The results showed that the photodegradation was the main approach of the microcystins elimination.,while biodegradation, bioaccumulation, and adsorption had also contribution in reducing the concentration of microcystins in water.