氧化还原梯度下污泥对含硫矿区重金属污染土壤微生物修复的影响

Utilization of municipal sludge to remediate mining tailing contamination either solve the disposal problem of municipal sludge, also contribute to solve metal mine pollution problem, with good economic feasibility. Various types of soluble organic matter in municipal sludge affect sulfur mineral interactions and microbial synthesis of new types of minerals, change the surface characteristics and adsorption characteristics of the soil minerals, which impact the desorption/migration and bioavailability of heavy metals. In this study, factorial batch experiments based on quantitative research will be conducted to test different sources of sludge on biological sulfur minerals transformation and the release of heavy metals impact. The combined application of soil column study will be conducted to investigate sludge addition on the biological activities of the rhizosphere soil by analyzing the soil mineral composition. Microbial transformation of sulfur minerals will reveal effects of sludge on heavy metals under soil-plant interaction. Finally, the project will be carried out a field study using sludge to remediate a mining site, where the application of high performance liquid mass spectrometry, Fourier transform infrared spectroscopy, and molecular biology will analyze the effects of sludge in the soil profile with mechanisms of microbial minerals biological synthesis. The success implementation of the project will help to improve the efficiency of the use of municipal sludge to remediate metal mining contaminated soils.

污泥修复矿区污染土壤既有助于解决城市污泥的出路问题，也有助于缓解金属矿区污染问题，具有良好的经济可行性。城市污泥中各类可溶性有机质通过与含硫矿物交互作用，影响微生物对土壤矿物的生成与侵蚀，改变土壤矿物的表面特征与吸附特性，进而影响重金属的解吸运移与生物有效性。本研究定量研究土壤大气环境界面氧化还原梯度下城市污泥对含硫矿物的生物转化与重金属释放的影响；同时结合应用根箱培养体系，研究分析根际界面污泥传输对根际土壤矿物成分变化的影响，揭示根际氧化还原梯度对含硫矿物的微生物转化作用以及对重金属固定的影响；最后，本项目将进行矿区污染土壤野外修复试验，并应用高分辨率液相质谱、傅里叶变换红外光谱、电子显微、以及荧光分析等现代分析手段，分析鉴定污泥在氧化还原梯度下影响土壤剖面微生物矿物生物合成的机制。本项目的顺利实施将有助于指导提高利用城市污泥修复金属矿区污染土壤的效率与安全性。

污泥修复矿区污染土壤既有助于解决城市污泥的出路问题，也有助于缓解金属矿区污染问题，具有良好的经济可行性。城市污泥中各类可溶性有机质通过与含硫矿物交互.作用，影响微生物对土壤矿物的生成与侵蚀，改变土壤矿物的表面特征与吸附特性，进而影响重金属的解吸运移与生物有效性。本研究结果显示，土壤环境中的铁离子形态变化对土壤中的重金属形态分布具有重要的作用。在水淹环境下，土壤中的铁存在形态从无定形态向结晶态和硫氧结合态转化，而以铜为主的其他重金属在土壤中的存在形态也随之变化，从易溶解的水溶态和无定形铁结合态，变为比较稳定的与结晶态铁和硫氧结合态铁结合在一起的难溶解态，从而得到固定。在白菜种植试验中，污泥炭的添加，增加了土壤中的微生物群落丰度，提高了土壤中脲酶和脱氢酶的活性。在种植结束的时候，对白菜植株的分析显示，污泥炭有效的抑制 了重金属在植物体内的迁移。