Biochar-mediated polycyclic aromatic hydrocarbon contamination remediation: trends and frontiers

In response to the significant environmental challenge posed by polycyclic aromatic hydrocarbon (PAH) contamination, extensive research efforts have focused on biochar-mediated remediation. Based on literature retrieval from the Web of Science Core Collection (WOSCC) and the Scopus database spanning the years 2000 to 2025, this paper conducts bibliometric statistical analysis of the field. Current publishing trends, leading contributing countries, influential authors and institutions, journal distributions, research hotspots and emerging directions were systematically reviewed. Furthermore, the development of biochar-mediated PAHs remediation research reveals three evolutionary stages. The initial stage centered on the foundational use of biochar for PAH pollution control, emphasizing soil contamination and optimizing the adsorption capacities of various biochars. The second stage shifted towards biochar modification techniques and applications across multiple contaminated media, while concurrently initiating the exploration of degradation and remediation methods. The research focus in the third phase has shifted towards the development of integrated synergistic remediation systems. These systems combine biochar with advanced oxidation processes and biological agents. This synergistic strategy not only enhances degradation efficiency but also overcomes the limitations of single remediation methods, such as incomplete mineralization or secondary pollution issues. The research scope has expanded from terrestrial soils to the emerging issue of PAHs in marine environments. Recent studies have begun exploring the application of algae-based and marine-specific biochar. Future research should prioritize elucidating synergistic remediation mechanisms at the molecular level, addressing the critical lack of large-scale field validation data especially for marine environments, and tailoring specific biochars to enhance remediation efficiency for PAHs in diverse media such as seawater.