Priyasha Fernando, a Ph.D. candidate in energy and mineral engineering, spent time at the University of Auckland in New Zealand, upcycling grape marc—the solid residue from wine production—into biovaluable products using microbial electrofermentation. Her plan focuses on improving the process by applying mild electrical conditions to enhance microbial activity and increase the efficiency of waste conversion. The NSF-IGE program funded the internship.
Before her internship, Fernando’s research at Penn State focused on the sustainable treatment of acid mine drainage (AMD) using bio-electrochemical systems (BESs), combining electrochemistry, microbiology, and mineral chemistry. Her work aims to remove and recover critical metals from contaminated water, promoting resource-efficient AMD treatment with minimal chemicals and waste.
What made you choose your major or area of study?
During my undergraduate studies in chemical engineering, I developed a deep interest in addressing environmental pollution, particularly from industrial sources such as wastewater. I thoroughly enjoyed the lab work that blended chemistry and microbiology. Afterward, I completed a master's degree in environmental engineering, focusing on wastewater treatment and reuse. I have always been motivated to address new environmental challenges by transforming problems into sustainable solutions or resources. That passion led me to join EME, where I discovered a vibrant research environment that broadened my interests and drew me into projects on acid mine drainage treatment and sustainable resource recovery.
What was a typical day like?
I operated a lab-scale electro-fermentation reactor in batch mode using upscaled grape marc. A typical day included setting up experiments, taking daily samples, monitoring key parameters, recording data, and analyzing results to evaluate system performance. The setup shared core principles with my bio-electrochemical systems (BES) at Penn State, but it incorporated a novel electro-fermentation concept specifically adapted to this new substrate and environment. Working on an island presented logistical challenges, such as shipping delays, which required sourcing local materials while adhering to stricter safety protocols and laboratory regulations.
What was the biggest challenge?
The initial setup was complicated because everything, including the instruments and connections, was so different and had been unused since 2019 in the environmental engineering research lab. I had to build my reactor by reconnecting old equipment and sourcing local parts, since shipping to New Zealand can take longer. The electrochemical control system also used different hardware and software than what I typically work with in Penn State's Environmental Engineering lab. I relied on remote troubleshooting with technical support in Pennsylvania, and emails sent on Sunday usually received replies by Tuesday in New Zealand time. The lab followed strict environmental standards, minimizing hazardous waste and ensuring full compliance with New Zealand regulations. It was a challenging, yet rewarding, experience that strengthened my adaptability, problem-solving skills, and commitment to sustainable research.
What was your favorite part?
Bringing a new concept to the research team and seeing how it improved the process and overall system performance. It was exciting to apply my Penn State experience in a completely different research setting and to watch the results come together faster than expected. Working closely with the team in Auckland gave me new perspectives on problem-solving and experimental design while strengthening my confidence in leading research discussions. The success of this project has now led to a growing partnership between Penn State and the University of Auckland, where we plan to continue and expand this work through international collaboration.
What is the potential impact?
They say you produce about one bottle of grape marc, which includes the skins, seeds, and stems, for every two bottles of wine made. With nearly 30 billion bottles of wine produced around the world each year, that creates a tremendous amount of waste. In New Zealand, winemaking alone generates more than 50,000 tons of grape marc every year. This byproduct has a low pH of around 3.0, so farmers have to be careful when applying it to soil because of its acidity. Disposing of it can cost wineries around NZD 90 per ton and adds to landfill waste, which conflicts with New Zealand's goal of achieving zero waste to landfill by 2050. Developing a process to upcycle this material into valuable organic compounds provides both environmental and economic benefits, supporting a circular economy that turns winemaking byproducts into useful and sustainable resources.