喀斯特石漠化土壤及沉积物中典型重金属污染物源解析与蓄积机制

It is more and more serious for the fragile ecological environment region due to soil heavy metal high background and exogenous heavy metal pollution in southwest typical Karst rocky desertification area. The source analytical and the mechanism of migration and conversion and accumulation of As and Hg in soil and water sediment is one of the key issues to be solved in this area, and it has an important significance for comprehensive management of the regional ecological environment. However, the research reports are not enough. The project is planned in the preliminary research work based on the accumulation, the soil and main water sediment in typical rocky desertification area was as the research object, applying the basic theories and methods of modern physical chemistry and earth science, and using advanced analysis equipment and technology, to explore the space form differentiation characteristics and environmental chemical behavior for heavy metal As and Hg, and to clarify pollutants main source and the way in soil and water sediment. Simulation experiments (including Leaching, irrigation, rainfall and absorbtion) will be done to deep study the migration transformation process of As and Hg in the soil, with the morphological characteristics of As and Hg, soil properties and other indicators, and to analysis the impact factors in leaching, adsorption - desorption processes for As and Hg. The results will ascertain As and Hg migration and transformation and accumulation mechanism in the soil and sediment in the stone desertification area, and provide the basis for heavy metals As and Hg prevention in the area.

西南典型喀斯特石漠化区土壤重金属高背景及来自外源重金属污染使该地区本已脆弱的生态环境更加严重。土壤及水体沉积物中主要重金属污染物As和Hg来源解析和迁移转化积累机制研究是本地区亟待解决的关键问题之一，对该区域生态环境综合治理具有重要意义，然相关研究报道较少。本项目拟在前期调查研究工作积累基础上，以典型石漠化区土壤和主要水体沉积物为研究对象，应用现代物理化学及地学等基本理论方法，采用先进的分析设备及技术手段，探索重金属As和Hg的空间形态分异特征以及环境化学行为，阐明污染物主要来源与途径。并结合室内模拟实验（淋溶、灌溉、降雨及吸附），辅以As和Hg形态特征，土壤理化性质等指标，深入研究As和Hg在土体中迁移转化过程，分析As和Hg污染物淋溶、吸附-解吸特性及其主要影响因子，以期探明石漠化区土壤和沉积物中As和Hg重金属的迁移转化积累机制，为该区重金属As和Hg污染防治提供依据。

广西重金属高背景地区砷（As）和汞（Hg）污染问题较为突出，特别是在喀斯特石漠化地区。该项目采用重金属污染物空间分异特征结合稳定同位素源解析的方法，探索广西典型喀斯特石漠化地区土壤和水体沉积物中砷和汞的分布特征以及来源，并结合实验室模拟As和Hg在石漠化土壤中的迁移蓄积规律研究两种主要污染物的环境行为特征。项目通过野外调查结合实验室分析，明确了典型石漠化地区砷和汞的区域污染特征，不同石漠化程度土壤中砷和汞的分布特征和关键因子，以及主要水体沉积物中污染物的分布及来源。结合研究区域石漠化分布特征，研究两种主要重金属污染物迁移和蓄积规律。已经发表或录用研究论文6篇。