珠江流域典型母质发育土壤重金属关键形态时空演变的微观机制

项目名称： 珠江流域典型母质发育土壤重金属关键形态时空演变的微观机制

项目编号： No.U1401234

项目类型： 联合基金项目

立项/批准年度： 2015

项目学科： 管理科学

项目作者： 李永涛

作者单位： 华南农业大学

项目金额： 235万元

中文摘要： 土壤溶液离子态重金属是决定其生物有效性的关键形态，其分布转化与土壤微团聚体结构和生物地球化学过程密切相关，研究其时空演变的微界面过程是土壤环境领域重要前沿课题。以珠江流域典型母质发育重金属污染土壤为研究对象，利用土柱-Donnan膜系统研究土壤自由和结合态重金属离子结合特征、生物有效性和空间分布规律。利用长期定位观测揭示环境因子驱动的重金属形态转化与演变规律。利用同步辐射和多表面量化模型研究微团聚体和纳微米颗粒物理结构对重金属表面吸附和内结构固持的分异特征，阐明影响重金属非均质空间分布的微界面机制。利用模拟体系揭示土壤铁氧化还原和有机质循环耦合重金属形态转化过程和关键微生物，阐明影响重金属关键形态演变的生物地球化学机制。最终在宏观尺度上阐明纳微米级微界面影响土壤溶液纳摩尔级重金属离子时空演变的微观机制，为全面准确评估珠江流域土壤环境质量演变提供科学依据。

中文关键词： 重金属离子；微团聚体；生物有效性；生物地球化学；珠江流域

英文摘要： The ionic speciations of heavy metals in soil solution are the key speciations which determine the bioavailability of heavy metals. The distribution and transformation of heavy metal ionic have close relationships with the micro-aggregate structure and biogeochemical process in soil. Investigating the spatial-temporal evolution of heavy metal ions and micro-interface process mechanism are the significantly important research frontier in the area of soil environmental issues. Our proposed study will examine the heavy metal contaminated soil developed from the typical soil parent materials of the Pearl River basin, with four specific aims as: (1) to characterize the binding properties, bioavailability and spatial distribution in soil of free and complex heavy metal ions with soil column-Donnan membrane technology; (2) to reveal the transformation and evolution of heavy metal speciation which is driven by environmental factors with long-term observation and stable isotope technique; (3) to investigate the effect of physical structure of the soil micro-aggregates and nano-micron particles on the differentiation characteristics of surface adsorption and immobilization of the internal structure thus clarify the micro interface mechanism influenced by the heterogeneous spatial distribution of heavy metals using Synchrotron radiation technology and Multi-surface model; (4) to clarify the biogeochemical mechanisms of heavy metal key speciations transformation mechanism and reveal the key transformation processes and microorganisms in the presence of iron oxidation-reduction reaction and organic matter cycle within simulated system. Our study is expected to illuminate the microcosmic mechanism of spatial-temporal evolution that nano-micron interface effect nanomolar heavy metal ionic at macro scale and will also provide scientific support for comprehensively and accurately assess the environment quality evolution from the Pearl River Basin.

英文关键词： Heavy metal ions;Microaggregates;Bioavailability ;Biogeochemistry;Pearl River Basin