The increasing presence of persistent organic pollutants in global water resources has created an urgent need for effective and sustainable remediation methods. In a comprehensive review published in Catalysts, authors Petr Leinweber, Jonáš Malý, and Tomáš Weidlich explore how carbon-based materials like biochar and activated carbonActivated carbon is a form of carbon that has been processed to create a vast network of tiny pores, increasing its surface area significantly. This extensive surface area makes activated carbon exceptionally effective at trapping and holding impurities, like a molecular sponge. It is commonly More can revolutionize wastewater treatment. By acting as catalysts for ozone-based oxidation, these materials provide a powerful way to eliminate complex chemical residues from hospitals, pharmaceutical factories, and the textile industry that traditional biological treatments often fail to remove.

The review details how these carbonaceous catalysts work through both direct and indirect reaction mechanisms. While ozone is a strong oxidant on its own, its efficiency is often hampered by poor mass transfer and selectivity. However, the addition of biochar or activated carbon facilitates the decomposition of ozone into hydroxyl radicals. These radicals are non-selective and significantly more reactive, allowing them to attack and mineralize virtually any oxidizable organic pollutant into harmless products. This surface-triggered mechanism is particularly effective because the porous structure of the carbon also serves as an adsorbent, bringing the pollutants and the reactive oxygen species into close contact.

Quantitative data presented in the review underscores the remarkable speed and efficiency of this approach. In studies of real wastewater containing over twenty different biologically active compounds, an ozone input assisted by these processes achieved 99.7% removal of the blood pressure medication telmisartan and over 99.9% removal of the anti-inflammatory drug diclofenac. Most of this degradation occurred within the first minute of treatment, demonstrating that catalytic ozonation is not just thorough, but exceptionally rapid. Similar success was noted in the textile industry, where catalytic ozonation using doped carbon materials increased the reduction of total organic carbon by nearly 20% compared to using ozone alone.

The economic and environmental advantages of using biochar over traditional treatment additives are significant. While activated carbon is a high-performance material, its production is energy-intensive and results in a positive carbon footprint, with prices reaching approximately 20 dollars per kilogram. In contrast, biochar is derived from inexpensive 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 waste like rice husks, which cost as little as 0.025 dollars per kilogram. Even after the necessary pyrolytic processing and modification, the final price of biochar remains between 5 and 10 dollars per kilogram, making it a much more accessible option for large-scale industrial applications.

Ultimately, the combination of air-based ozone generation and biochar application represents a highly sustainable “advanced oxidation process”. By turning agricultural residues into active catalysts, this method addresses the twin challenges of waste management and water scarcity. While further research is needed to ensure the consistency of these materials on an industrial scale, the existing evidence points to a future where cleaning up our most persistent chemical pollutants is both environmentally benign and economically viable.

Source: Leinweber, P., Malý, J., & Weidlich, T. (2026). Carbon-Based Catalysts in Ozonation of Aqueous Organic Pollutants. Catalysts, 16(1), 41.