The journal Discover Sustainability recently featured a critical review by Idris O. Sanusi, Reuben S. Dangana, Michael B. Okon, and a collaborative team of international researchers regarding the transformative role of biochar in modern wastewater treatment. Their analysis highlights a growing global crisis where untreated industrial and domestic wastewater releases heavy metals, pesticides, and pharmaceuticals into the environment. These pollutants are often resistant to traditional treatment methods, leading to their accumulation in the food chain and posing severe health risks to humans, including the disruption of fundamental biological processes and the development of deadly diseases. The research team argues that biochar, produced by carbonizing 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 under low-oxygen conditions, provides a cost-effective and highly available solution to these challenges.

The findings emphasize that while simple adsorption can move pollutants from water onto biochar, the true innovation lies in using biochar as a support for advanced oxidation processes. By integrating biochar with metal oxides or light-harvesting frameworks, researchers have created catalysts that generate highly reactive species capable of physically breaking down organic contaminants. For instance, the study notes that biochar-supported systems have achieved a 99.2% removal rate for rhodamine B and a 95.68% removal of tetracycline in as little as seven minutes. This is a significant improvement over traditional methods, as the porous structure and electrical conductivity of the biochar increase the number of active sites where chemical reactions can occur, preventing the clumping of catalytic particles and maximizing light absorption.

Beyond chemical pollutants, the manuscript highlights the potential of biochar-based systems for microbial inactivation. While much of the current research has focused on the elimination of E. coli, the review points out that biochar composites can achieve nearly 100% disinfection in real-world scenarios, such as treating stormwater. These advanced materials serve as a conductive bridge that facilitates the transfer of electrons, which in turn fuels the production of radicals that destroy pathogens. The researchers found that these systems are not only efficient but also highly stable, maintaining their performance over multiple cycles of use, which makes them viable for long-term practical applications in wastewater facilities.

The study also explores the environmental and economic benefits of using diverse waste sources—ranging from corncobs and hickory wood to sewage sludge and shrimp shells—to create these high-performing catalysts. By repurposing waste into water-cleaning agents, the technology supports a circular economy and reduces the overall energy demand of decontamination efforts. This is particularly promising for decentralized or rural wastewater treatment systems in regions like sub-Saharan Africa and India, where solar-powered biochar reactors could provide a sustainable path to clean water. The integration of solar energy with biochar catalysts further reduces operational costs and enhances the sustainability of the process by utilizing a broader range of the light spectrum to drive chemical reactions.

Despite the overwhelming success of these laboratory findings, the authors urge for more research into the practical, large-scale application of biochar in real wastewater environments. Most studies currently rely on simulated pollutants in controlled settings, yet real-world water contains complex mixtures that can impact catalyst performance through surface fouling. Additionally, the review calls for a deeper investigation into the ecotoxicity of used catalysts and the potential for metal leachingLeaching is the process where nutrients are dissolved and carried away from the soil by water. This can lead to nutrient depletion and environmental pollution. Biochar can help reduce leaching by improving nutrient retention in the soil.   More to ensure that the treatment process does not introduce secondary pollutants into the ecosystem. Strengthening the engineering of these materials to work across a wider range of acidity and alkalinity levels will be crucial for their future commercial feasibility.

Ultimately, the manuscript positions biochar-based advanced oxidation as a disruptive and essential technology for environmental remediation. By harnessing the natural properties of carbonized biomass and enhancing them through scientific modification, the industry can address the escalating global threat of water pollution. The combination of high removal efficiency, renewable material sources, and potential for sustainable energy integration marks these composites as a cornerstone for future carbon-neutral water treatment strategies. As the technology moves toward commercialization, it promises to transform hazardous wastewater into a safely managed resource, protecting both public health and the natural world.

Source: Sanusi, I. O., Dangana, R. S., Okon, M. B., Mahmud, K. M., Adepoju, A. A., Abdulrahman, B. D., Agbaje, A. B., & Lawan, K. A. (2026). Techniques and applications of advanced oxidation processes for degrading pollutants in wastewater using biochar-based catalysts: a critical review. Discover Sustainability.