Advances in Biological Sulfur Cycling-Based Treatment and Resource Recovery of Sulfur Pollutants in Acid Mine Water

Abstract

Acid mine drainage (AMD) arises from coupled sulfur–iron biogeochemical transformations and is typically characterized by severe acidity, high sulfate concentrations, and elevated dissolved metal loads. Although sulfate-reducing bacteria (SRB)-based bioremediation has been extensively investigated, its long-term effectiveness is often limited by low-pH stress, insufficient electron donor supply, and poor control over sulfide fate. This review uses biological sulfur cycling as an integrated framework to examine AMD treatment and sulfur resource recovery. It first outlines the sulfur transformation pathways involved in AMD formation, including sulfur oxidation, sulfate reduction, and sulfur disproportionation. It then evaluates the engineering feasibility of SRB-mediated sulfate removal through three interrelated constraints: pH buffering capacity, electron donor availability, and sulfide management, with comparison of treatment systems ranging from passive wetlands to enhanced bioreactors. Finally, it discusses downstream sulfide valorization pathways, with emphasis on sulfur-oxidation-based processes and the operational factors governing product selectivity. Overall, AMD remediation and sulfur recovery are presented as sequentially coupled stages regulated by system-level sulfur fluxes, offering a process-based perspective for improving the stability and engineering applicability of sulfur-cycle-driven biotechnologies.