He, Wang, et al (2024) Properties of biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More colloids and behaviors in the soil environment: Influencing the migration of heavy metals. Environmental Research. https://doi.org/10.1016/j.envres.2024.118340

In the realm of soil remediation, biochar emerges as a promising candidate for tackling heavy metal (HM) contamination. Derived through biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More pyrolysisPyrolysis is a thermochemical process that converts waste biomass into bio-char, bio-oil, and pyro-gas. It offers significant advantages in waste valorization, turning low-value materials into economically valuable resources. Its versatility allows for tailored products based on operational conditions, presenting itself as a cost-effective and efficient More, biochar undergoes processes that lead to the formation of micro- and nano-sized biochar colloids (BCs). These BCs, possessing rough surfaces, abundant elemental species, and multiple functional groups, exhibit unique colloidal properties due to their microscopic scale.

The migration of BCs in soil is a complex interplay influenced by colloidal properties and environmental factors such as soil colloids and conditions. The large specific surface area, rich oxygen-containing functional groups, and minerals on the BCs’ surface contribute to their mobility. Moreover, BCs may impact HMs in soil through various mechanisms, including electrostatic adsorption, ion exchange, surface complexation, and precipitation.

This comprehensive review sheds light on the physicochemical and migratory properties of BCs, emphasizing the internal and external factors shaping their movement in soil. The potential effects of BCs on HMs are highlighted, offering a theoretical foundation for optimizing HM-contaminated soil post-remediation using biochar. It also raises the need for targeted detection and analysis methods in future studies to confirm the innovative idea that BCs influence the presence of HMs in soil and mitigate potential environmental toxicities.