Arsenic Removal From Acid Mine Drainage Using Acid-Tolerant Bacteria

Abstract

Acid mine drainage (AMD) has a low pH and contains harmful metals, making it a severe problem in the mining industry. Neutralization treatment using slaked lime is widely applied to remove potentially toxic metals and adjust the pH. However, this generates neutralized sludge containing large amounts of harmful metals. Therefore, in this study, we propose a bacterial bioprocess for removing metals before neutralization. Acid- and metal-tolerant bacteria were isolated from neutral soils and utilized as As removers from AMD. The Paenathrobacter sp. strain H1 removed As (43.6%) and Fe (10.6%) from AMD in a single-batch test (pH 1.95; initial concentrations were 6.13 and 283 mg L⁻¹, respectively). Repeated batch tests using fresh cells enhanced the As removal ratio, achieving successful removal of As (95.3%) and Fe (75.5%). Although further research is required, this study has substantial implications for the development of a sustainable AMD treatment to suppress harmful waste generation.