A review on the application of biochar in anaerobic biofiltration for wastewater purification: technologies, performance, and future perspectives

Adesina, Aramide Adenike and Adeyeye, Isaac Uwanaobong and Okuneye, Oluwatosin Ebunlomo and Abdulkareem, Yusuf Temitope (2025) A review on the application of biochar in anaerobic biofiltration for wastewater purification: technologies, performance, and future perspectives. Global Journal of Engineering and Technology Advances, 22 (3). 097-112. ISSN 2582-5003

Water pollution, driven largely by industrial activities, presents a pressing environmental challenge, compromising ecosystems and human health globally. Conventional wastewater treatment methods, such as adsorption and membrane filtration, while effective, are often limited by high costs and inefficiencies in handling complex effluents, particularly in resource-limited settings. This review explores the integration of biochar a porous, carbon-rich material derived from biomass pyrolysis into anaerobic biofiltration systems as a sustainable solution for wastewater purification. Focusing on literature predominantly from the past decade, biochar’s unique properties was examined, including its high surface area (10–500 m²/g), porosity (0.1–0.5 cm³/g), and oxygen-containing functional groups, which enable it to serve as an effective adsorbent, biofilm carrier, and electron transfer mediator. Empirical studies demonstrate that biochar-amended anaerobic biofilters significantly enhance treatment performance, achieving, up to 74% chemical oxygen demand (COD) removal and improved pathogen reduction (1.35 log-units of E. coli) compared to traditional systems. These improvements stem from biochar’s ability to boost microbial activity and pollutant sequestration. However, challenges such as variability in biochar properties, scalability, and the lack of long-term performance data impede widespread adoption. This review highlights key research gaps and proposes future directions, including standardizing biochar production and conducting extended field studies, to optimize its application in anaerobic biofiltration technologies for efficient and cost-effective wastewater treatment.