Biocover Technologies for Landfill Gas Mitigation: Analyzing Two Decades of Research Trends, Development, and Future Directions

Abstract

Landfill gas emissions, primarily methane, pose significant environmental challenges due to their contribution to climate change and the degradation of local air quality. Biocover technologies, which use microbial methane oxidation, have become a notable sustainable mitigation strategy. This study assessed two decades of trends and development in biocover research. A total of 227 English-language peer-reviewed papers published from 2004 to 2024 were obtained from the Scopus database. Thereafter, bibliometric tools such as R Studio-based Bibliometrix and VOSviewer were employed to analyze publication trends, keyword clusters, and thematic mapping and evolution. The study identified core themes such as methane oxidation, methanotrophs, and biochar-based biocovers, which are central to methane mitigation efforts. Thematic mapping revealed an evolution from fundamental methane oxidation mechanisms to applications like biogeochemical covers and circular economy integration. The study identified innovations such as using compost, biochar, and hybrid materials to enhance methane oxidation efficiency. Despite substantial progress, challenges remain regarding regional disparities, material optimization under varying climatic conditions, and scalability. Future research should focus on biochar-blended substrates, long-term field validation, artificial intelligence-driven optimization techniques, and expanding research to Africa. The findings provide critical insights for researchers, practitioners, and policymakers, supporting evidence-based strategies for advancing landfill gas management and contributing to global methane mitigation efforts. © The Author(s), under exclusive licence to Iranian Society of Environmentalists (IRSEN) and Science and Research Branch, Islamic Azad University 2025.