Professor Saswati Chakraborty (L) and research scholar Shweta Singh with their constructed wasteland model. IIT Guwahati
Indian Institute of Technology (IIT) Guwahati researchers have carried out a study of coal mines on the ‘bioremediation’ of acid mine drainage (AMD) in constructed wetlands. This is the first study to demonstrate the bioremediation of AMD from the Northeastern Coalfields (NEC) using constructed wetlands (CW). 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. This research provides an efficient sustainable treatment approach to mitigate AMD pollution while addressing the long-term operational sustainability issues encountered in constructed wetlands receiving AMD. Furthermore, a biochemical mechanism has been developed to understand the functioning of different fundamental processes that co-occur in constructed wetlands.
Saswati Chakraborty, Department of Civil Engineering, IIT Guwahati, said, “The preliminary findings from this research propose an effective strategy to manage the extremely acidic AMD from the NEC, which remains to be a challenging source of water pollution and environmental contamination due to mining activity in this region.”
The study entailed the bioremediation of AMD produced from the NEC, Assam, and revealed the successful application of CW with emphasis on critical factors governing its treatment performance. This exploratory study recommends the optimisation of the chemical oxygen demand/sulfate [COD/SO4(2-)] ratio and provides an efficient sustainable solution to mitigate AMD pollution in the Northeast region of India. The implementation of this technology will ensure ecosystem restoration thereby, benefitting all the stakeholders at large.
Speaking about this Research, Shweta Singh, research scholar, IIT Guwahati, said, “The generation of AMD is a perpetual environmental issue from the NEC and to address this concern, we investigated the potential bioremediation approach using nature-based technology – CWs and obtained some very promising results which can be further implemented at field-scale applications by coal mining industries.”
The present research work provides a better experimental explanation for a sustainable long-term treatment approach to mitigate AMD pollution using simpler organic carbon sources in CWs.