季节性冻融条件下稀土尾矿库区周边土壤稀土元素形态、分布规律研究

土壤作为人类赖以生存的根基，其稀土元素的生态安全问题不容忽视，深入理解冻融条件下稀土元素的形态、分布规律能够为污染控制技术提供理论指导。本项目以我国典型的北方稀土尾矿库区周边土壤为研究对象，采用矿区采样与实验室模拟相结合的研究方法，选取土壤胶体与微生物为切入点，对冻融条件下尾矿库区周边土壤稀土元素的形态、分布规律进行研究；首先，在时间/空间尺度上，测定土壤理化指标, 稀土元素的总量及形态，土壤胶体、微生物等，采用多元的统计分析方法揭示稀土元素的分布与多环境因子的耦合作用机理；其次室内冻融模拟结合野外观测，研究不同冻融温度、速率、次数等对土壤的理化指标及稀土元素分布的影响，并利用XRD和FTIR等技术表征稀土-土壤胶体物质的络合态结构，揭示季节性冻融条件下土壤胶体/微生物对稀土尾矿库区周边土壤稀土分布的贡献率及其主要的影响因子，为寒冷地区土壤稀土元素的科学管理及其生态风险管控提供理论依据。

Land resources is depending capital of human existence, therefore, problems of ecological safety of rare earth elements in soil can’t be ignored. Full understanding of the form and distribution of rare earth elements under the conditions of freezing and thawing, which could provide some theoretical guidance for pollution control technology. This project takes the soil around the typical rare earth tailings reservoir in the north of China as the research object, and adopts the research method of mining area sampling and laboratory simulation. Soil colloids and microorganisms were selected as the entry point to study the form and distribution of rare earth elements in the soil. Firstly, we will to collect the data including physical and chemical indexes of soil, total amount and form of rare earth elements, soil colloids, microbes on the time / space scale, and so on. Then, we will use multivariate statistical analysis method to reveal the coupling mechanism between the distribution of rare earth elements and multi-environmental factors. Secondly, we will to study the effects of the number of times on the physical and chemical indexes and the distribution of rare earth elements in soil under freezing and thawing temperatures and rates. Futher, the complexation structure of rare-earth and soil colloid materials was characterized by XRD and FTIR techniques. The contribution rate of soil colloid / microorganism to the distribution of rare earth elements in soil around the rare earth tailings reservoir and its main influencing factors were revealed, which provided a theoretical basis for the scientific management of soil rare earth elements and ecological risk management in cold regions.