IIT-G develops method to mitigate acid mine drainage in Northeastern coal mines
GUWAHATI, June 28: Researchers from the Indian Institute of Technology-Guwahati (IIT-G) have carried out a first-of-its-kind study to demonstrate the bioremediation of acid mine drainage (AMD) from the Northeastern Coalfields (NEC) using constructed wetlands.
Acid mine drainage refers to the acidic wastewater generated from coal mines (or any polymetallic mines) containing high amounts of sulfate, iron and various toxic heavy metals.
A constructed wetland is an artificial wetland to treat sewage, grey water, storm water runoff or industrial wastewater.
“This research provides an efficient and sustainable treatment approach to mitigate AMD pollution while addressing the long-term operational sustainability issues encountered in constructed wetlands receiving AMD,” a statement from IIT-G issued here on Tuesday, said.
Furthermore, a biochemical mechanism has been developed to understand the functioning of different fundamental processes that co-occur in constructed wetlands.
“The key benefits of the research include optimisation of parameters with the use of simple organic carbon to provide an effective sustainable solution for the mitigation of AMD pollution,” it said.
The research was led by Prof Saswati Chakraborty, department of civil engineering, IIT-G, along with her research scholar Shweta Singh, who studied the season-wise variation (monsoon, pre-monsoon and post-monsoon) of AMD discharge in NEC.
The research team conducted a laboratory-scale study wherein the preliminary findings demonstrated its potential for field-scale applications at the NEC for direct mine drainage.
“This research developed an experimental methodology for the bioremediation of AMD and recommended optimising the COD (chemical oxygen demand) to sulfate ratio for long-term treatment of AMD in constructed wetlands. Results have successfully demonstrated the elimination of high acidity, sulfate and metals. Thus, it will help control water pollution and improve water quality through ecosystem restoration of the region,” the statement said.
Explaining the impact of the research, Prof Chakraborty said that the preliminary findings from the research propose an effective strategy to manage the extremely acidic AMD from NEC, which remains to be a challenging source of water pollution and environmental contamination due to mining activity in this region.
The implementation of the technology will ensure ecosystem restoration thereby benefitting all the stakeholders at large.
“The generation of AMD is a perpetual environmental issue from NEC and to address this concern, we investigated the potential bioremediation approach using nature-based technology – constructed wetlands and obtained promising results which can be further implemented at field-scale applications by coal mining industries,” research scholar, Singh said.
The researchers took the environmental and geographical variables of Northeast India into consideration while carrying out the study.