Recovery and co-GeneratIon of metals and energy by sustainable acid mine drainage treatment (REGAIN)

The REGAIN project aims to demonstrate an integrated system for biological remediation of acid mine drainage (AMD) together with recovery of valuable metals and electricity using a microbial fuel cell (MFC) and reverse electrodialysis (RED).

The MFC will be fed a mixture of AMD and wood hydrolysate at the anode side, where sulfate-reducing bacteria reduce sulfate to sulfide, which is further oxidized to sulfur by sulfide-oxidizing bacteria. Electrons from the anode pass through the external circuit, while protons pass through membranes towards the cathode for oxygen reduction and electricity generation. To increase electricity, a RED unit will be incorporated between the anode and cathode chamber of the MFC. The RED produces electricity by mixing AMD with alkali solution through alternating ion exchange membranes. Stacking of multiple MFC-RED devices in different configurations and optimization will be investigated. Scenarios for scale-up and grid/market integration will be analyzed in collaboration with LTU's Electrical Energy Engineering group.

One working on the project is Annie Modestra Jampala who is a postdoc.

Where are you originally from, and what is your academic background?

“I am originally from India, and I completed my Bachelor's and Master's degree in Biotechnology. I have always been interested in research that focuses on solving environmental challenges. During my PhD, I focused on contemporary issues, i.e. climate change and energy needs with sustainability in mind. My research over the last 10 years has been focused on solving complex environmental problems through environmental engineering/biotechnology, especially waste/sewage treatment using advanced biocatalyzed technologies. In addition, I have also worked on biogeneration of energy and synthesis of value-added bio-based products linked to wastewater treatment and CO2 biosequestration.”

What is the main focus of your research within the project?

“The focus of my research within the project "REGAIN" is to develop a sustainable solution for bioremediation of acid mine drainage (AMD) water together with electricity generation and recovery of metals as a valuable resource. For this, we use a microbial fuel cell (MFC) and a reverse electrodialysis cell (RED) for bioconversion of sulfate to sulfide followed by targeted metal recovery. Stacking of multiple MFC-RED units in different configurations and optimization will be investigated to increase the output voltage.”

What attracted you to this specific research project?

“As an environmental biotechnologist, I have a passion for research that focuses on addressing societal and environmental challenges. The "REGAIN" research project under the SUN call is consistent with the goal of developing and demonstrating sustainable solutions for the critical challenges in the mining industry that are very necessary to maintain environmental resilience. "REGAIN"'s goal is to address environmental challenges that are real, practical and sustainable, which has made me very passionate about the work.”

What are some of the main research questions or objectives that you focus on during your postdoctoral research?

“The main research questions that I am focusing on during my postdoctoral research is to develop innovative, eco-friendly and sustainable solutions that protect the environment in relevance to AMD treatment. The idea is to address the challenges facing the mining sector through new, bio-based solutions.”

Are there any specific skills or knowledge areas that you aim to improve during your time on the project?

“This project involves elemental, structural and morphological characterization of metal (nano) particles. I would like to explore analysis of metal particles via SEM, XRD, EDS for a more detailed analysis. For targeted metal recovery, I would also like to optimize methods that are simple and efficient.”

How do you see the results of this project having an impact, either locally or globally?

“Currently, conventional methods for AMD treatment, such as neutralization and precipitation to detoxify AMD, are energy intensive and generate highly non-degradable sludge. As an alternative, MFC will be used to reduce sulphate and recover metals in a sustainable and economically feasible way. This new method of AMD treatment will have great potential to address the critical challenges of the mining industry, such as the reduction of sulfate and metal loadings, thereby avoiding toxic effects on aquatic environments both locally and globally.”

How do you think this postdoctoral project can contribute to the goal of the green transition?

“Green transition refers to a transition to a sustainable and environmentally friendly society/environment. "REGAIN" aims to provide solutions to achieve cost-effective, sustainable and environmentally friendly remediation of AMD, which is very necessary for the mining industry operations. The proposed concept of "REGAIN" is novel and useful and is expected to play a significant role in achieving the goal of the green transition.”

What unique challenges or opportunities do you foresee working in northern Sweden?

“Coming from a tropical region in India, the weather in northern Sweden surprised me. In the beginning, adapting to the winter was a bit challenging, but I was able to learn many new things. There are good opportunities to participate in winter activities and to explore the northern lights which I think you should experience when living in northern Sweden. On the other hand, the summer is beautiful and warm which gives an opportunity to see the midnight sun. I was inspired by the exercise routine that people follow here, and I learned to follow it as well.”