Work

Biochar-Based Remediation of Heavy Metal-Contaminated Soils: Mechanisms, Synergies, and Sustainable Prospects

Year: 2025

Type: review

Abstract: This study systematically explores the mechanisms and application potential of biochar in remediating heavy metal-contaminated soils. Particular emphasis is placed on the role of raw materials and pyrolysis conditions in modulating key physicochemical properties of biochar, including its aromatic structure, porosity, cation exchange capacity, and ash content, which collectively enhance heavy metal immobilization. The direct remediation mechanisms are categorized into six pathways: physical adsorption, electrostatic interactions, precipitation, ion exchange, organic functional group complexation, and redox reactions, with particular emphasis on the reduction in toxic Cr6+ and the oxidation of mobile As3+. In addition to direct interactions, biochar indirectly facilitates remediation by enhancing soil carbon sequestration, improving soil physicochemical characteristics, stimulating microbial activity, and promoting plant growth, thereby generating synergistic effects. The study evaluates combined remediation strategies integrating biochar with phytoremediation and microbial remediation, highlighting their enhanced efficiency. Moreover, practical challenges related to the long-term stability, ecological risks, and economic feasibility in field applications are critically analyzed. By synthesizing recent theoretical advancements and practical findings, this research provides a scientific foundation for optimizing biochar-based soil remediation technologies.

Source: Nanomaterials

DOI: 10.3390/nano15191487

Authors: Yuxin Wei, Jingjing Ma, Kuankuan Liu, Shuai Zhang, Junqi Wang

Institution: Xi'an Jiaotong University

Language: English

Topic: Heavy metals in environment

Subfield: Pollution

Field: Environmental Science

Domain: Physical Sciences

SDGs: Life on land, Responsible consumption and production

Open Access status: gold

Estimated APC paid: $2,896