颤蚓扰动对湖泊沉积物中镉迁移转化的影响机制研究

项目名称： 颤蚓扰动对湖泊沉积物中镉迁移转化的影响机制研究

项目编号： No.51509011

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 其他

项目作者： 郭伟杰

作者单位： 长江水利委员会长江科学院

项目金额： 20万元

中文摘要： 重金属污染已成为我国主要水环境问题之一。底栖动物扰动可通过改变水体沉积物的理化性质影响重金属的环境行为，而生物扰动下沉积物关键理化性质的变化特征与重金属迁移转化过程之间的耦合关系尚不清楚。.项目选取常见底栖动物耐污种颤蚓为扰动生物，以典型水体重金属污染物镉（Cd）为研究对象，探讨颤蚓扰动对沉积物中Cd迁移转化的影响机制。通过对颤蚓扰动过程中沉积物/水相关键理化性质指标的动态监测，探讨颤蚓扰动下沉积物微环境的变化特征及趋势；通过分析沉积物/水相中不同赋存形态Cd的含量变化，识别颤蚓扰动对水环境中Cd迁移、转化和释放的影响特征及规律；通过分析沉积物/水相中不同形态Cd含量与关键理化性质指标间的相关关系，揭示生物扰动通过改变沉积物理化环境特征影响Cd迁移转化的作用机制。.本研究有助于揭示水环境中生物扰动和沉积物中重金属环境行为之间的耦合关系，为湖泊重金属污染的潜在生态风险评价提供理论依据。

中文关键词： 湖泊沉积物；重金属；迁移转化；底栖动物；生物扰动

英文摘要： Heavy metal pollution has become one of the main aspects of water environmental deterioration in our country. Macroinvertebrate activity can alter the physical and chemical properties of sediments, further influencing the environmental behaviors of heavy metals across the sediment-water interface. However, the coupling relationship between the key physicochemical properties of sediment and the transport and transformation of heavy metals in sediments under bioturbation has not been well understood by far. .Our experimental was based on indoor microcosms, selecting tubificid, a typical pollution resistant species, as the bioturbation agents and cadmium (Cd), a typical kind of heavy metal pollutants in sediment, as the target pollutant. The aims of this study were to: investigate the physicochemical properties of sediments and its change tendency under bioturbation based on the monitoring data; reveal the effect of tubificids bioturbation on transport and transformation characteristics of Cd in sediments through analyzing the concentration of different Cd fractionation in sediment and water phase; reveal the mechanism for the influence of physicochemical properties change of sediment caused by tubificids on environmental behaviors of Cd through the analysis of the relationship between the key physicochemical indexes and the content of different Cd fractions in sediment and water phase. .This study will help to explore the mechanism for the influence of bioturbation on environmental behaviors of heavy metal and provide theoretical foundation for the evaluation of the potential ecological risk in lake sediments.

英文关键词： lake sediment;heavy metal;transport and transformation; benthic invertebrate;bioturbation