生物质炭对重金属土壤环境行为及影响机制研究进展

Research Progress of the Mechanism of Action of Heavy Metal in Soil Environment by Biochar

综述了生物质炭基本结构特性及其影响因素,阐述了生物质炭对土壤重金属形态转变、迁移性以及生物有效性的影响,并对其作用机制做了探讨。研究发现,生物质炭基本结构特性主要与自身理化性、材料来源和制备条件相关。由此对污染土壤重金属形态转变及其运动变化产生不同影响,主要引起重金属的有效态向残渣态等无效态转变,其迁移和生物有效性降低引起植株累积重金属能力下降。其主要作用机制为吸附和固化作用,通过直接或间接改变土壤pH、有机质含量、CEC、土壤酶活性和团聚体等环境,达到修复目的。因此,在利用生物质炭钝化重金属污染土壤时,应因地制宜,筛选和施用适宜生物质材料。今后应继续探究完善其作用机制,并对修复土壤进行长期监测与防控。

The basic structure characteristics and influencing factors of biochar were reviewed. The effects of bio-char on the speciation, migration and bioavailability of heavy metals in soil were discussed, and the mechanism was explored as well. Recent research has found that the basic structure characteristics of biochar were mainly related to their physical and chemical properties, material sources, and preparation conditions. The formation of heavy metals in contaminated soil was effected by biochar. It caused heavy metals to transform to residual state and other invalid state, which reduced the accumulation of heavy metals in plants. The main mechanism of action was adsorption and solidification through changing soil pH, organic matter content, CEC, soil enzyme activity, and aggregation. Therefore, the use of biochar to passivate heavy metals in soil should be adapted to local conditions by screening and applying suitable biomass materials to achieve the best results.