Treatment Options for Acid Mine Drainage: Remedial Achievements Through Microbial-Mediated Processes

Abstract

Acid mine drainage (AMD) is considered to be one of the major environmental problems faced by the mining industries due to its toxic and lethal impact on the ecosystem. Generation of million tons of mine wastes like tailings, slags, waste rocks/ore bodies, etc. are the major sources of AMD generation in metalliferous/coal mine, due to the biologically mediated oxidation of sulfidic waste. Low pH and high heavy metal and sulfate concentration are the major characteristic features of the AMD environment and considered to be lethal than single-factor pollutants. Owing to its toxic effects, development of both preventive and treatment options remain the main focus of scientific research for decades. Prevention is a better option than complex treatment processes; however, due to several environmental factors preventive measures are limited from its application in several mining locations. In order to minimize the impact of AMD on ecosystem, several remediation technologies have been developed including chemical and biological treatment options. Due to the high capital investment and other reasons, chemical technologies are less preferred over biological treatments. Nowadays, several studies have been conducted to develop promising biological treatment system to attenuate AMD and recover metals from such environment. The present chapter discusses the cause and generation of AMD, available prevention measures, and treatment technologies using metabolic capacities of sulfate-reducing bacteria (SRB), which is the main player of biological treatment system.