Wood-based biochar: A sustainable remedy for soil and water contamination in the agricultural field

Review paper

Abstract

Wood-based biochar, produced through the pyrolysis of wood biomass in an oxygen-limited environment, is a highly porous carbon material with diverse environmental applications. Its unique physicochemical properties, including high surface area, porosity, and abundant functional groups, enable it to adsorb trace metals (e.g. Pb²⁺, Cd²⁺) and organic contaminants (e.g. PAHs, pesticides) effectively through mechanisms such as surface complexation, cation exchange, π-π interactions, and hydrogen bonding. These interactions make biochar a promising material for soil remediation, water purification, and carbon sequestration. In agriculture, wood-based biochar enhances soil quality by improving nutrient retention, water-holding capacity, and microbial activity, increasing crop productivity and reducing reliance on chemical fertilisers. Its ability to sequester carbon binding it into a stable form for centuries contributes to climate change mitigation by reducing greenhouse gas emissions. However, the efficacy of biochar depends on factors such as feedstock type, pyrolysis conditions, and soil properties, necessitating tailored production and application strategies. This article explores the production and properties of wood-based biochar, its interaction mechanisms with organic and inorganic contaminants, and its environmental applications in soil amendment, wastewater treatment, and carbon storage.

Keywords: biochar; wood-based biochar; pyrolysis; cation exchange; trace metals; organic contamination