Mineral-assisted microbial remediation for heavy metals and organic pollutants: Mechanisms, applications and perspectives

Minerals play a pivotal role in the biogeochemical cycling of a variety of pollutants via extracellular electron transfer (EET). Recently, increasing attention has been given to the mechanisms and systems involving mineral-microbe electron transfer. However, a systematic review focusing on mineral-assisted microbial remediation and the associated EET mechanisms remains lacking. This review addresses this gap by systematically summarizing recent advances in mineral-involved biotransformation and biodegradation of heavy metals (HMs), halogenated organic compounds (HOCs), and antibiotics. Special emphasis is placed on how minerals leverage their redox properties, electrical conductivity, and photosensitivity to facilitate microbial EET and pollutant transformation. The diverse roles of minerals, including electron donors, acceptors, mediators, and photocatalysts, are thoroughly summarized under both dark and illuminated conditions. Additionally, this review highlights the different types of mineral-involved microbial remediation systems that have been constructed based on the roles of minerals mentioned above, as well as their potential application scenarios in different environmental conditions. Ultimately, this paper provides suggestions and prospects for advancing microbial-mineral coupling mechanisms and system construction, including exploring complex microbial-mineral interfaces mechanisms, designing advanced composites, and applying synthetic biology, which offering theoretical and technical guidance for establishing efficient, environmentally sustainable, and low-carbon microbial remediation systems.