不同晶型铁氧化物对洲滩湿地沉积物中重金属生物有效性的影响

Heavy metals in sediment deteriorate the aquatic environment quality and seriously threaten the behaviors of aquatic lives. Reduction of these internal elements bioavailability in Lakes, therefore, plays an effective role in sediment remediation. In this work, different crystalline iron oxides are employed to deal with Cd and Pb in Dongting Lake sediment, which displays an alternation of wetting and drying. The mechanism and influence of three iron oxides on interaction with two metals are examined. To understand how sulfate reducing bacteria (SRB) behave under anaerobic/aerobic conditions, the reductive decomposition and magnetization of iron oxides and the effect of SRB under the contaction with heavy metal on the formation of sulfide and its role of heavy metal fixation will also be analyzed. Hence, this research will put forward a strategy for lowering the bioavailability of heavy metal via radically removing heavy metal from sediment by iron oxide, as well as the theoretical guidance and technical support for remediation of wetland sediment.

生物有效性是沉积物中重金属的修复至关重要的评价指标。本项目基于洞庭湖洲滩湿地沉积物干湿交替的特征，以沉积物中重金属Cd、Pb为目标污染物，拟探究不同晶型铁氧化物对沉积物重金属的作用机制，弄清在厌氧和缺氧的条件下，硫酸盐还原菌（SRB）对铁氧化物的还原分解及磁性变化的影响，探究在沉积物中重金属的毒性胁迫下SRB还原产生硫化物的机理及其对重金属固定的影响，利用不同手段识别洲滩沉积物季节性淹水等环境因素所引起的生物有效性的响应特征，在此基础上综合评价不同晶型磁性铁氧化物对重金属（Cd、Pb）的生物有效性影响，以期为原位修复-移除减量洲滩湿地沉积物中重金属提供理论依据和技术支持。

生物有效性是沉积物中重金属的修复至关重要的评价指标。本项目基于洞庭湖洲滩湿地沉积物干湿交替的特征，以沉积物中重金属Cd、Pb为目标污染物，探究了不同晶型铁氧化物对沉积物重金属的作用机制，考察了在厌氧和缺氧的条件下，硫酸盐还原菌（SRB）对铁氧化物的还原分解及磁性变化的影响，探究在沉积物中重金属的毒性胁迫下SRB还原产生硫化物的机理及其对重金属固定的影响，利用不同手段识别洲滩沉积物季节性淹水等环境因素所引起的生物有效性的响应特征，在此基础上综合评价不同晶型磁性铁氧化物对重金属（Cd、Pb）的生物有效性影响，以期为原位修复-移除减量洲滩湿地沉积物中重金属提供理论依据和技术支持。