Wastewater management remains a global challenge, with over 75% of untreated wastewater discharged into freshwater bodies, causing severe health and environmental impacts. A promising, cost-effective solution involves 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 derived from agricultural lignocellulose-based 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 (ALCB). This material, made from agricultural residues like corn stalks and rice husks, offers high adsorption capacities for pollutants due to its porous structure and functional chemical groups.

In their critical review published in Environmental Functional Materials, lead author Aqib Zahoor and colleagues highlight the potential of ALCB biochar for wastewater treatment. Biochar is produced through thermal processes such as 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, gasificationGasification is a high-temperature, thermochemical process that converts carbon-based materials into a gaseous fuel called syngas and solid by-products. It takes place in an oxygen-deficient environment at temperatures typically above 750°C. Unlike combustion, which fully burns material to produce heat and carbon dioxide (CO2​), gasification More, and torrefaction. Pyrolysis is particularly effective, converting up to 35% of ALCB into biochar. This process is versatile and allows tailoring biochar properties for specific uses by varying conditions like temperature and feedstockFeedstock refers to the raw organic material used to produce biochar. This can include a wide range of materials, such as wood chips, agricultural residues, and animal manure. More type. The resulting biochar has proven efficient in removing heavy metals (like lead and cadmium) and organic pollutants from wastewater via mechanisms such as ion exchange and surface adsorption.

The sustainability benefits are significant. Using agricultural waste to produce biochar supports circular economy practices by reducing waste and converting it into a valuable resource. Moreover, biochar serves as a carbon sink, contributing to climate change mitigation.

Despite its potential, challenges remain in optimizing production processes and scaling applications, particularly in developing regions. Addressing these barriers through improved technologies, policy support, and market development could unlock biochar’s full potential, creating a sustainable and affordable approach to wastewater treatment and environmental protection.

Zahoor, et al (2025) Agricultural Lignocellulose Biochar Material in Wastewater Treatment: A Critical Review and Sustainability Assessment. Environmental Functional Materials. https://doi.org/10.1016/j.efmat.2024.12.005