Biochar application for the remediation of soil contaminated with potentially toxic elements: Current situation and challenges

Yi Wu; Yuhang Yan; Zongwei Wang; Zhongxin Tan; Tuo Zhou

doi:10.1016/j.jenvman.2023.119775

Biochar application for the remediation of soil contaminated with potentially toxic elements: Current situation and challenges

J Environ Manage. 2024 Feb:351:119775. doi: 10.1016/j.jenvman.2023.119775. Epub 2023 Dec 8.

Authors

Yi Wu¹, Yuhang Yan¹, Zongwei Wang¹, Zhongxin Tan², Tuo Zhou³

Affiliations

¹ Hubei Key Laboratory of Soil Environment and Pollution Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China; Ministry of Agriculture and Rural Affairs, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China.
² Hubei Key Laboratory of Soil Environment and Pollution Remediation, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China; Key Laboratory of Arable Land Conservation (Middle and Lower Reaches of Yangtse River), College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China; Ministry of Agriculture and Rural Affairs, College of Resources and Environment, Huazhong Agricultural University, Wuhan, 430070, China. Electronic address: tanzx@mail.hzau.edu.cn.
³ China State Key Laboratory of Power Systems, Department of Energy and Power Engineering, Tsinghua University, Beijing, 100084, China.

PMID: 38070425
DOI: 10.1016/j.jenvman.2023.119775

Abstract

Recently, biochar has garnered extensive attention in the remediation of soils contaminated with potentially toxic elements (PTEs) owing to its exceptional adsorption properties and straightforward operation. Most researchers have primarily concentrated on the effects, mechanisms, impact factors, and risks of biochar in remediation of PTEs. However, concerns about the long-term safety and impact of biochar have restricted its application. This review aims to establish a basis for the large-scale popularization of biochar for remediating PTEs-contaminated soil based on a review of interactive mechanisms between soil, PTEs and biochar, as well as the current situation of biochar for remediation in PTEs scenarios. Biochar can directly interact with PTEs or indirectly with soil components, influencing the bioavailability, mobility, and toxicity of PTEs. The efficacy of biochar in remediation varies depending on biomass feedstock, pyrolysis temperature, type of PTEs, and application rate. Compared to pristine biochar, modified biochar offers feasible solutions for tailoring specialized biochar suited to specific PTEs-contaminated soil. Main challenges limiting the applications of biochar are overdose and potential risks. The used biochar is separated from the soil that not only actually removes PTEs, but also mitigates the negative long-term effects of biochar. A sustainable remediation technology is advocated that enables the recovery and regeneration (95.0-95.6%) of biochar from the soil and the removal of PTEs (the removal rate of Cd is more than 20%) from the soil. Finally, future research directions are suggested to augment the environmental safety of biochar and promote its wider application.

Keywords: Biochar-based material; In-situ removal; Interaction mechanisms; Risk; Systemic remediation engineering.

Publication types

Review

MeSH terms

Charcoal
Environmental Restoration and Remediation*
Metals, Heavy* / analysis
Soil
Soil Pollutants* / analysis

Substances

biochar
Metals, Heavy
Soil
Soil Pollutants
Charcoal