A critical review on biochar-based catalysts for the abatement of toxic pollutants from water via advanced oxidation processes (AOPs)

• Published in: The Science of the total environment 2022-11, Vol.849, p.157831-157831, Article 157831
• Main Authors: Gupta, Arijit Dutta, Singh, Harinder, Varjani, Sunita, Awasthi, Mukesh Kumar, Giri, Balendu Shekhar, Pandey, Ashok
• Format: Article
• Language: English
• Subjects: Advanced oxidation processes; Biochar; Catalyst; Reactive oxygen species; Wastewater treatment
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2022.157831

Proper waste disposal is a key towards sustainable development. Wastewater treatment is delineated by the application of efficient, economic and novel catalysts. Biochar is derived from the thermochemical conversion of biomass or any carbonaceous materials and is considered as one of the most eco-friendly substitute for activated carbon. Owing to its large surface area, porosity, crystallinity and active functional groups, the biochar-based catalysts has been extensively applied for the abatement of toxic pollutants from wastewater streams. While most of the reviews focus on the adsorptive properties of the biochar, this review critically analyses the recent development of biochar-based catalysts in the field of advanced oxidation processes (Fenton-like systems, photocatalytic and sonocatalytic systems). The presence of persistent free radicals and oxygen-containing functional groups renders biochar to act as catalyst. The mechanisms accompanying catalytic performance of biochar-based catalysts have also been reviewed. However, the research in this area is quite at an initial phase, and many advancements schemes are essential prior to scale-up and commercialization. Future researches should be devoted to more efficient and rigorous understanding of the structural properties of biochar to engineer the catalytic degradation of targeted pollutants in wastewater treatment. [Display omitted] •Biochar can act as catalyst for the mineralization of pollutants from wastewater.•Role of biochar as catalyst in sono/photo/Fenton system have been reviewed.•Pollutant degradation occurs through OH, SO4, h+ and ROS in the biochar.•Future researches and challenges to scale-up have been elucidated.•Biochar-based catalysts can outperform conventional catalysts.