典型钨矿区河流沉积物中钨的污染特征及迁移释放机制研究

Tungsten as a new class of environmental pollutants, its ecological security has aroused widespread concern in the world. Although tungsten resources are very rich in China, the attention to the pollution of tungsten is not enough and the history of research is short, which leads to little known about distribution, accumulation, migration and transformation of tungsten in the environment in China. The representative Gannan tungsten mine area is one of the main source of tungsten resources in China, taking it as the research object. We research contents, speciation distribution characteristics and its changing trend of 8 kinds of heavy metal including tungsten in sediments in different water seasons, ascertain the law of seasonal functional transformation about the effect of river sediment on the source/sink of heavy metals, and the effect of the composition and organic matter on the speciation distribution of heavy metals in river sediments, reval the influence of the unique water quality environment on the migration and transformation of heavy metals in the river sediments, comprehensively evaluate the level of heavy metal contamination and potential ecological risk. By dynamic simulation experiment, we research on the relationship between the concentration of the water-sediment interface，the speciation distribution characteristics for tungsten and the environmental parameters, reveal the releasing mechanisms about the heavy metal W in sediments upward to overlying water. The above research can provide theoretical basis for the prevention and control of heavy metal especially tungsten in river sediments of tungsten mine area.

钨作为一类新兴的环境污染物，其生态安全性已引起全球广泛关注。我国虽然是钨资源大国，但对钨污染的重视不够，研究历史较短，导致人们对我国钨在环境中的分布、富集水平及迁移转化知之甚少。项目以我国钨资源主产地之一的赣南典型钨矿区河流沉积物为研究对象，研究不同水期沉积物中包括钨在内的8种特征重金属的含量、形态分布特征及其变化趋势，探明矿区河流沉积物对重金属源/汇作用的季节性功能转化规律，以及河流沉积物组成及有机质对重金属形态分布的影响，揭示矿区独特水质环境对河流沉积物中重金属迁移的影响规律，并综合评估重金属的污染水平和潜在生态风险；通过动态模拟实验，研究重金属钨在水-沉积物界面的浓度及形态分布特征与环境参数的相关性，揭示沉积物中重金属钨向上覆水体的释放机制。通过以上研究，可为钨矿区河流沉积物重金属污染尤其是钨的污染防治提供理论依据。

钨的生态安全性已引起全球广泛关注，但我国对钨在环境中的分布、富集、迁移及环境风险研究较少。项目以赣南典型钨矿区桃江河水体沉积物为研究对象，系统研究了丰、平、枯三个水期沉积物中W、Cu、Pb、Zn、Cd、Cr、Hg、As等8种重金属的含量、形态分布特征及其空间变化趋势，开展了矿区河流沉积物中各种重金属来源解析和相关性分析，研究了河流沉积物SOM、CEC等理化指标对重金属形态分布的影响规律，并综合评估了河流水体及沉积物中8种重金属的污染水平和潜在生态风险，结果表明桃江河沉积物中Cd、Hg存在极强生态风险，以枯水期污染最为严重；通过室内动态模拟实验，查明了钨及其他重金属在上覆水-沉积物的浓度及形态分布规律以及与pH值、盐离子强度、NH4+、温度及水体紊动强度等环境参数的相关性。项目研究成果为典型矿区河流沉积物重金属污染尤其是钨的污染防治提供了基础理论依据。