几种典型重金属在蓝藻毒素迁移中的作用

Sustained and intensive human activities had put serious impact on the health and security of aquatic ecosystems in China. Eutrophication had been happened in many lakes while most of the sediment in the lake was polluted by heavy metals. Both carcinogenic cyanobacterial toxins such as microcystin brought from eutrophication and heavy metals would do great harm to human health. Previous studies showed that heavy metals would function with microcystins, which may change the distribution and fate of carcinogenic microcystins in the aquatic ecosystem and brought risks to aquatic habitat and humans. The aim of this program was to study the rule of microcystin distribution and fate under heavy metal pollution and give early warnings to prevent related risks.In this program, through simulation experiment of heavy metal pollution in eutrophic aquatic ecosystems, we study the distribution of microcystin and heavy metal in the aquatic habitat, water, sediment et al. In addition, we would carry out field investigation to study the distribution of microcystin and heavy metal in the wild lakes suffered from both heavy metal pollution and eutrophication. Then the microcystin degradation rate in both waters and sediment would be test in the lab. The aim of this study was to reveal the effect of heavy metal pollution on microcystin distribution and transportation in aquatic ecosystem and its potential risks to aquatic habitat and humans. Our research will benefit human health protection and security of aquatic ecosystems.

富营养化蓝藻水华毒素污染和湖库底质重金属污染是我国当前面临的重大环境问题。两污染物间存在多种类反应作用，对毒素环境迁移存在多方面影响。从过程和原理机制上揭示有害重金属与致癌蓝藻毒素间的联合作用，加深认识蓝藻毒素的迁移规律，将有利于科学评估其对生态系统和人类健康的风险，为水环境的预警和污染控制提供科学指导。本项目将采用实验室内研究、生态模拟实验并结合湖泊野外生态调查的进一步补充验证来研究重金属污染下蓝藻毒素环境迁移规律。具体内容包括：跟踪重金属污染前后蓝藻毒素在泥-水 相中的平衡分配，并在室内补充研究重金属污染前后蓝藻毒素在水体和底泥中的降解速率变化，调查两污染物在复合污染湖泊水柱垂直空间中的联合分布，观察重金属污染前后水生植物和水产品积累蓝藻毒素总量差异，本项目旨在阐明蓝藻毒素水环境迁移中重金属污染物的影响机制与作用过程，为科学评估毒素对湖泊水生态系统及人类健康的风险提供依据。

富营养化蓝藻水华毒素污染和湖库底质重金属污染是我国当前面临的重大环境问题。两污染物间存在多种类反应作用，对毒素环境迁移存在多方面影响。本项目采用实验室内研究、生态模拟实验并结合湖泊野外生态调查的进一步补充验证来研究重金属污染下蓝藻毒素环境迁移规律。底泥重金属污染物对蓝藻毒素具有较强的亲和吸附力，重金属污染越重的底泥其吸收富集的蓝藻毒素总量也越高。同时多种重金属污染物如铁、铜和铅等均对蓝藻毒素具有光催化降解作用，在阳光能照射到的浅水湖泊底泥表层能加速蓝藻毒素在该处的降解速率，降低底泥中残留的蓝藻毒素量，具备光反应活性的重金属含量越高，底泥残留毒素能力越低。重金属污染环境可极大地促进浮水植物凤眼莲对蓝藻毒素的吸收积累，同时在一定浓度范围内以对大型挺水植物香蒲吸收积累毒素具有促进作用，加重蓝藻毒素的生态风险危害。10月枯水季节鄱阳湖水体中毒素的垂直空间分布与其重金属污染物分布有着很强的关联，在水体表层及底泥表层分布少而在中部分布高，主要潜在原因为重金属的光催化降解作用，鄱阳湖底泥重金属含量与其毒素残留量呈线性负相关。. 本研究还发明了一种用于去除蓝藻和蓝藻毒素的聚胺铁改性土壤，聚胺铁改性土壤配方合理，该材料具备性能稳定，操作简单，对污水中的杂质具有良好的抗干扰能力，同时可以极大程度净化水体中的悬浊物、总氮、总磷等，并且可改善蓝藻水华水体溶解氧浓度。该材料非常适合大规模制备，能够高效去除蓝藻细胞功能，同时所用材料价格低廉，环境相容性好，对水体无毒副作用，可大规模用于湖泊、河流、池塘等各类富营养水体蓝藻水华危害防治。