State Key Laboratory of Coal Combustion, Huazhong University of Science and Technology
Department of New Energy Science and Engineering, School of Energy and Power Engineering,Huazhong University of Science and Technology

生物炭在固持土壤重金属(HMs)方面具有广阔的应用前景,其修复效果受到理化特性以及土壤环境的影响。因此,探究生物炭的成炭调控与重金属固化能力,对于优化生物炭制备生产过程具有重要的指导意义。总结了不同制备工艺下生物炭的理化特性变化,并梳理了生物炭固化重金属的主要机理以及各种老化因素对生物炭理化特性变化的影响。生物炭主要通过孔隙吸附、阳离子交换、官能团络合以及矿物沉淀等方式来固化土壤中的重金属,其各项机制的吸附贡献占比受到热解温度、原料种类、停留时间、热解气氛等因素的影响。生物炭老化会导致其理化特性变化,如孔道破碎、含氧官能团分解、不稳定碳析出等,而不同的老化因素会对生物炭产生不同的影响。通过探究各老化因素的作用机理以及其对重金属固化的影响,可以从热解成炭的角度提高生物炭稳定性及有效性,从而减少环境因素对生物炭固化重金属效果的影响,实现对生物炭物化特性及土壤修复能力的有序调控。同时,还展望了未来生物炭施用研究方向,旨在为合理评估生物炭有效性以及指导生物炭修复重金属污染土壤提供参考。

Biochar has vast potential for application in the remediation of heavy metals (HMs) in soil. The remediation effect depends on the physicochemical characteristics of biochar and the soil environ ment. Exploring the mechanisms of biochar regulation and its ability to retain HMs can provide guidance for optimizing the biochar preparation process. This paper summarizes the changes in the physicochemical properties of biochar under varying preparation methods, explains the primary mecha nism of HMs immobilization, and reviews the effects of biochar aging on its physicochemical properties. The main mechanisms of HMs adsorption by biochar in soil include pore adsorption, cation exchange, functional group complexation, and mineral precipitation. The relative importance of different adsorption mechanisms depends on factors such as pyrolysis temperature, raw material, residence time, and atmosphere. Additionally, biochar aging leads to changes in its physicochemical properties, such as pore breakage, decomposition of oxygen-containing functional groups, and unstable carbon precipitati on. Different aging factors have varying impacts on biochar. Exploring the mechanisms of various aging factors and their effects on HMs adsorption, coupled with an in -depth examination of the pyrolysis process and carbon formation mechanism, can minimize the impact of environmental factors on the ef fectiveness of HMs adsorption. Furthermore, this paper proposes future directions for biochar applica tion, aiming to provide a reference for evaluating the effectiveness of biochar and guide its application in remediating HMs contaminated soil.

国家自然科学基金面上资助项目(51976075);国家自然科学基金面上资助项目(52176187);国家自然科学基金杰出青年基金资助项目(52125601)

廖玮,张雄,杨海平,等.生物炭成炭调控及固化土壤重金属研究进展[J].能源环境保护,2024,38(2):14-23.

LIAO Wei, ZHANG Xiong, YANG Haiping, et al. Advances in biochar carbonization regulation and remediationof soil heavy metals[J]. Energy Environmental Protection, 2024, 38(2): 14-23.