Sulfate-Reducing Bacteria Application for Heavy Metal Precipitation in Acid Mine Drainage Treatment

Abstract

Acid mine drainage generated from mining activities contains elevated concentrations of sulfate ions and dissolved heavy metals, posing severe environmental risks to aquatic ecosystems, soil quality, and groundwater resources. Sustainable treatment methods are therefore essential for effective contaminant removal and long-term environmental protection. The present study investigates the application of sulfate-reducing bacteria for heavy metal precipitation in acid mine drainage treatment under controlled biological and operational conditions. The research focuses on evaluating sulfate reduction efficiency, metal precipitation behavior, microbial activity, and treatment stability associated with biologically mediated remediation systems. Experimental analysis was conducted to examine the influence of pH, temperature, carbon source availability, hydraulic retention time, sulfate concentration, and metal loading on bacterial performance and contaminant removal efficiency. Results demonstrate that sulfate-reducing bacteria effectively convert sulfate into sulfide under anaerobic conditions, promoting the precipitation of dissolved heavy metals as insoluble metal sulfides and significantly reducing metal mobility in treated water. The study further reveals that optimized environmental conditions substantially enhance microbial metabolism and improve treatment performance for metals such as iron, copper, zinc, cadmium, and lead. Increased organic substrate availability contributed to stable sulfate reduction activity and enhanced metal removal efficiency. Comparative assessment with conventional physicochemical acid mine drainage treatment methods confirms the advantages of biological sulfate reduction, including lower chemical consumption, reduced sludge generation, and improved environmental sustainability.