水稻根际重金属与有机质微观结构及交互作用的分子机制

项目名称： 水稻根际重金属与有机质微观结构及交互作用的分子机制

项目编号： No.21207114

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 环境化学

项目作者： 杨建军

作者单位： 浙江大学

项目金额： 26万元

中文摘要： 根际是土壤重金属向水稻体内迁移的主要通道；根际有机质是重金属的重要吸附载体，阐明水稻根际重金属与有机质的交互作用是控制水稻土重金属污染，保障农产品安全的关键之一。同步辐射技术可在分子水平上表征重金属和有机质微观结构，是从本质上揭示有机质与重金属交互作用的分子机制的强力手段。本项目主要利用同步辐射技术，结合根际原位毫米技术和电化学-质谱技术，针对重金属在水稻吸收过程中必经的根际和根表铁膜屏障，以铜/锌为目标污染物，在分子水平上表征根际有机质微观结构和铜/锌分子形态，研究根际有机结合态铜/锌分子形态转化过程；揭示有机质与铜/锌交互作用对根际铁价态转化的响应机制；证实根表铁膜是否为有机质-铁氧化物复合体，弄清铁膜-DOM-重金属共存体系中铜/锌与DOM的结合机制；以最终阐明水稻根际重金属与有机质交互作用的分子机理及其对土壤重金属生物有效性的影响，为水稻土重金属污染控制和农产品安全保障提供理。

中文关键词： 重金属；水稻土；同步辐射技术；颗粒态有机质；硫

英文摘要： Rhizosphere is the major passage of heavy metals (HM) from soil to rice. Rhizospheric organic matter (OM) is an important absorber of HM. Therefore, it is critical to clarify the mutual interactions of HM and OM in the rhizosphere of rice for the control of soil HM contamination and food safety. Synchrotron based techniques can characterize the micro-structures of HM and OM at the molecular level, providing a strong technique support to reveal the mechanisms on the mutual interactions of HM and OM in essence. This project will mainly use the synchrotron based techniques, together with the in-situ millimetric technique and online electrochemistry-mass spectrometry (EC-MS), and focus on copper/zinc and the two screens (rhizosphere and root iron plaque) encountered by HM during their uptake by rice, to investigate the following scientific questions: 1) To characterize the molecular speciation of copper/zinc and micro-structures of OM in the rhizosphere of rice; 2) to study the rhizospheric transformation of the molecualr speciations of copper/zinc; 3) to reveal the effect of iron oxidation state on the interaction of copper/zinc and OM; 4) to make sure if iron plaque is organic-Fe oxides complexes and clarify the combination mechanisms on copper/zinc and DOM in iron plaque-DOM-HM systems;5) to fully illustrate the

英文关键词： Heavy metals；Paddy soil；Synchrotron-based techniques；Particulate organic matter；Sulfur