Heavy metal removal and acid mine drainage neutralization with bioremediation approach

Abstract

Mining Industry can improve the national economic situation; however, it also can damage the environment, mainly because of its wastewater that contains heavy metal and acidic solid compounds. When exposed to free air, sulfide minerals can be naturally oxidized and create acid mine drainage (AMD), a highly acidic waste that can mobilize heavy metals towards the environment. This literature study will discuss practical and sustainable biological processing to remove AAT. Sulfate Reducing Bacteria (SRB) were isolated from AMD polluted soil and grown inside an AMD-containing batch reactor. The environmental conditions (temperature, AMD concentration, SRB concentration, and contact time) were controlled during this research. The implementation of pH sampling was conducted every day, and the heavy metal final result was measured with an Inductive Coupled Plasma Optical Spectrophotometry or ICP-OES. SRB produced Hbiogenic2S that reacts with heavy metal and creates metal sulfide sediment. The remediation process by SRB will create biogenic alkalinity as an SRB side product that plays a significant role in neutralizing acidic water. Remediation is also influenced by organic compounds such as animal waste, rice, hay, or coconut husks. In this research, SRB plays a significant role as biosorbent that utilizes organic compounds as electron sources. The iron removal efficiency in AMD reached 96% and occurred on a contact time of 144 hours. To reach similar efficiency removal on a pilot scale, we planned AMD bioremediation on a tube-shaped reactor with 7.3m3 with 3.5 m height and 0.88 of each reactor radiuses. This bioremediation study has provided an alternative solution for environmental management quality due to AAT pollution in water and groundwater around mining areas.