Textile Pollution Controlling Engineering Center of Ministry of Environmental Protection, College of Environmental Science and Engineering, Donghua University, Shanghai, 201620, China.
CRIBI Biotechnology Center, University of Padua, 35121, Padua, Italy.
Environ Sci Pollut Res Int. 2022 Oct;29(47):71871-71881. doi: 10.1007/s11356-022-20750-9. Epub 2022 May 23.
The preparation of magnetic biochar from sewage sludge and rice straw for heavy metal contaminated soil remediation has greater application prospects, but its remediation mechanism was rarely considered by combining soil physicochemical properties with microbial community. In this study, the effects of magnetic sewage sludge biochar (SSB) and rice straw biochar (RSB) on Cd and Pb immobilization in paddy soil were compared and analyzed by 60-day soil incubation experiments. The results illustrated that DTPA-Cd and DTPA-Pb were reduced by 51.53% (43.07%) and 53.57% (50.47%), while the percentage of residual fraction of the BCR procedure was enhanced by 31.27% (30.78%) of Cd and 27.25% (23.22%) of Pb in the SSB (RSB) treatment, respectively. Fe was detected on both SSB and RSB surfaces, but SSB had rougher and a larger specific surface area compared to RSB. The addition of SSB and RSB in paddy soil increased soil pH and TOC content, and affected the diversity and species of soil microbial community. Compared with the CK group, the relative abundance of Proteobacteria, Bacteroidota, and Lysobacter decreased, and the relative abundance of Actinobacteriota, Pontibacter, and Alkaliphilus increased with SSB and RSB treatments, all of which reflected the bioavailability of Cd and Pb reduction.
利用污水污泥和稻草制备磁性生物炭来修复重金属污染土壤具有更大的应用前景，但很少有人考虑将其修复机制与土壤理化性质和微生物群落结合起来。本研究通过 60 天的土壤培养实验，对比分析了磁性污水污泥生物炭（SSB）和稻草生物炭（RSB）对水稻土中 Cd 和 Pb 的固定效果。结果表明，与对照相比，SSB 和 RSB 处理分别使 DTPA-Cd 和 DTPA-Pb 降低了 51.53%（43.07%）和 53.57%（50.47%），BCR 程序中残渣态的比例分别增加了 31.27%（30.78%）和 27.25%（23.22%）。在 SSB 和 RSB 表面都检测到了 Fe，但 SSB 比 RSB 的表面更粗糙，比表面积更大。SSB 和 RSB 的添加增加了土壤 pH 值和 TOC 含量，并影响了土壤微生物群落的多样性和物种组成。与 CK 组相比，添加 SSB 和 RSB 处理后，变形菌门、拟杆菌门和赖氨酸芽孢杆菌的相对丰度降低，放线菌门、庞蒂杆菌属和耐碱菌属的相对丰度增加，这都反映了 Cd 和 Pb 的生物可利用性降低。
