阿哈湖和红枫湖沉积物铁锰循环及重金属垂向分布特征  

Iron and manganese cycling and vertical distribution of heavy metals in sediments of Aha Lake and Hongfeng Lake

作　　者：康亭 宋柳霆[1,2] 郑晓笛[1,2] 黄莹 杨洁[1,2] 滕彦国[1,2] 

机构地区：[1]北京师范大学水科学研究院,北京100875 [2]地下水污染控制与修复教育部工程研究中心,北京100875

出　　处：《生态学杂志》2018年第3期751-762,共12页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41473086);环保公益行业专项(201509031)资助

摘　　要：阿哈湖和红枫湖是云贵高原上位置相邻但沉积环境存在明显差异的两个湖泊,阿哈湖属于弱氧化至还原型沉积环境,而红枫湖属于氧化型沉积环境。为了对比不同沉积环境下湖泊体系重金属富集和迁移转化特征,本研究调查了阿哈湖和红枫湖沉积物及孔隙水中重金属的含量及剖面变化特征。结果表明:阿哈湖沉积物中Co、Ni和Zn含量较高,处于中度到重度污染水平;红枫湖仅As、Zn含量较高,其他元素基本处于无污染和轻微污染状态。两湖沉积物铁锰循环特征差异显著,与红枫湖相比,阿哈湖铁锰循环异常强烈,还原分带明显,主要是由于阿哈湖沉积物中铁、锰及硫含量以及Mn/Fe比值远高于红枫湖。据此,本文建立了阿哈湖和红枫湖沉积物早期成岩作用过程的铁锰循环概念模型。经陆源校正及相关性分析,证实铁锰循环对重金属的分布和迁移转化具有重要影响:阿哈湖沉积物中Co、Ni、Zn和As的迁移主要受Mn循环影响,Cu的迁移主要受Fe循环影响;而红枫湖沉积物中Co、Ni、Cu、Zn、Cr、As和Pb均受控于Fe的循环作用。Aha Lake and Hongfeng Lake are two adjacent lakes on the Yunnan-Guizhou Plateau, the sedimentary environments of which are different. The sedimentary environment of Aha Lake is weakly oxidizing to reducing whereas that of Hongfeng Lake is oxidizing. To compare the enrichment, migration, and transformation characteristics of heavy metals in lakes with different sedimentary environments, contents and vertical distributions of heavy metals in sediments as well as pore waters were investigated in Aha Lake and Hongfeng Lake. The results showed that contents of Co, Ni and Zn were relatively high with moderate to heavy pollution levels in the sediments of Aha Lake. For Hongfeng Lake, while the contents of As and Zn were relatively high, other heavy metals were unpolluted or slightly polluted. The characteristics of the cycling of Fe and Mn in two lakes were significantly different. In contrast to that in Hongfeng Lake, Fe and Mn cycling was extremely intense and the reduction zoning was more distinct in the sediments of Aha Lake, due to higher Fe, Mn, and S contents and Mn/Fe ratio. Based on those findings, we constructed a conceptual model of early diagenesis of Fe and Mn cycling process in the sediments of Aha Lake and Hongfeng Lake. Following terrigenous correction and correlation analysis, results showed that the cycling of Fe and Mn played an important role on the distributions, migrations and transformations of heavy metals. The migrations and transformations of Co, Ni, Zn and As were mainly influenced by Mn cycling, while that of Cu was mainly influenced by Fe cycling in Aha Lake. In contrast, the migrations and transformations of Co, Ni, Cu, Zn, Cr, As and Pb were influenced by Fe cycling in Hongfeng Lake.

关 键 词：阿哈湖 红枫湖 重金属 垂向分布 铁锰循环模式 

分 类 号：X524[环境科学与工程—环境工程]