有机物对土壤重金属的长期稳定性评估及驱动的分子机制

The heavy metal can be immobilized by organic matter in soil, which can also be activated in rhizosphere. However the long-term stability of heavy metal by organic matter is often questioned. In this study, the soil samples of long-term application of organic admendments on cropland and long-term polluted soil will be collected, and the fraction, specicfic compounds or functional groups in organic matter in relation to heavy metal in soil will be analyzed by chemistry, NMR and XAFS. Further, The chemdynamics of heavy metal fraction in soil of rhizosphere affected by applcation of organic admendments will be studied by plotted plan and incubatation, combined with NMR and XAFS. This research will help to understand deeply the long-term stability of heavy metal immobilized by organic admendment and the mechanism of interactions between organic admendments and soil heavy metal for predicting the heavy metal contamination risk during the application of organic waste on cropland.

有机物能够固定土壤重金属，提高根际土壤生物化学及重金属活性，但其对土壤重金属的长期稳定性效果还不得而知。本项目以Cu、Zn、Pb、Cr等为目标元素，通过采集不同年限有机物料长期施用土壤和重金属长期污染土壤，运用化学提取、核磁共振、同步辐射等手段，从分子水平揭示土壤中有机物与土壤重金属结合形态的变化特征；在此基础上，以典型土壤及其有机组分和模式土壤为研究对象，通过盆栽与培养试验研究有机物料对根际土壤生物化学活性与土壤重金属形态变化的动力学过程及交互作用，结合核磁共振、同步辐射等分析手段，探讨有机物料影响根际土壤重金属形态变化的驱动机制，评估有机物料对土壤重金属的长期稳定性效果，为合理评估与调控有机物料农用过程中造成的土壤重金属环境风险、推动我国畜禽粪等有机物料的资源化利用提供理论与技术依据。

有机物能够固定土壤重金属，提高根际土壤生物化学及重金属活性，但其对土壤重金属的长期稳定性效果还不得而知。本项目以Cu、Zn、Pb、Cr等为目标元素，通过采集不同年限有机物料长期施用土壤和重金属长期污染土壤，运用化学提取、核磁共振、同步辐射等手段，从分子水平揭示了土壤中有机物与土壤重金属结合形态的变化特征；在此基础上，以典型土壤及其有机组分和模式土壤为研究对象，通过盆栽与培养试验研究有机物料对根际土壤生物化学活性与土壤重金属形态变化的动力学过程及交互作用，结合核磁共振等分析手段，探讨了有机物料影响根际土壤重金属形态变化的驱动机制，评估了有机物料对土壤重金属的长期稳定性效果，为合理评估与调控有机物料农用过程中造成的土壤重金属环境风险、推动我国畜禽粪等有机物料的资源化利用提供了理论与技术依据。