Research progress and trends of biochar in the field of wastewater treatment by electrochemical advanced oxidation processes (EAOPs): a bibliometric analysis

Biochar (BC) as a novel low-cost and environmentally friendly porous material has been proved to possess great potential for application in the field of electrochemical advanced oxidation processes (EAOPs) for wastewater treatment. This study screened related articles from Web of Science© Database and conducted the bibliometric analysis. Research on the application of BC in EAOPs started as early as 2013 and has seen a surge in the last five years (2018-2022). China occupied the most joint publications (67.65% ratio) in this field. The early research in this field focused on the use of BC as electrode catalysts for oxygen reduction reaction in microbial fuel cells, facilitating the production of H2O2. Electro-Fenton is the main EAOPs technology for BC application. We anticipate that future research will focus on using BC as particle electrodes or an electro-catalyst in various traditional or novel EAOPs for wastewater treatment. Furthermore, the EAOPs+BC system can combine the adsorption performance of biochar with EAOPs to remove heavy metals and organic pollutants from wastewater in a sequential manner, thereby reducing its toxicity meanwhile. This study highlights the potential of biochar in EAOPs and helps practitioners and governments seeking to implement sustainable solutions for waste management and wastewater treatment.