Professor Marika Kokko develops sustainable solutions for CO2 utilisation

Professor Marika Kokko knows there is no quick fix to saving the environment. For her, advancing the transition to a circular economy is a long-term endeavour, with the development of processes playing a central role. Her research examines the capture of carbon dioxide and nitrogen and the integration of related biological processes with electrochemistry.

Kokko leads the Microbial Electrochemical Technologies research group, which specialises in the utilisation of bio-based carbon dioxide that is generated, for example, during the production of biogas, bioethanol and pulp. 

“Among other things, we investigate methods for converting carbon dioxide into short-chain fatty acids using microbes and renewable energy, aiming to produce raw materials for industry. Our goal is to replace fossil fuel-based chemicals,” Kokko says.

Kokko’s group is currently working with Professor Ville Santala of Tampere University and other project members on a project titled Industrial Symbiosis on CO2 and Waste and Side Stream Conversion to Sustainable Products (isoSUS), launched in the autumn of 2024. Supported by Business Finland, this project aims to develop an integrated process for converting short-chain fatty acids into chemicals with longer chain lengths, which can then be utilised, for example, as raw materials for bioplastics.

Another ongoing project for the group is the Recovery of Nitrogen from Reject Waters of Biogas Process (BioNH4) project, funded by Finland’s Ministry of the Environment. This project advances the bioelectrochemical recovery of ammonium nitrogen from municipal wastewater. Results are expected later this year. The process yields pure ammonium sulphate, which is suitable for use as a fertiliser. 

“Currently, ammonia is flushed down the drain with urine and faeces, and a significant amount of energy is expended to remove it from wastewater. Instead, we could use this energy to recover ammonia. The more nitrogen we can recover from local side streams and reintroduce into the cycle, the more sustainable its production becomes. This would also lead to greater self-sufficiency,” Kokko says. 

Driven by a commitment to make a positive impact on the environment

In upper secondary school, Kokko came to the realisation that she wanted to study environmental engineering. She was mathematically gifted, but her interest in the field was also driven by her commitment to environmental protection. Motivated by a strong desire to make a positive impact on the environment, she enrolled at the then-Tampere University of Technology (TUT) in 2003. 

While working on her master's thesis, the initial spark that led her to study environmental engineering grew into a blaze.

“Once I was able to join research projects in a laboratory, my fascination with the field grew exponentially. Experimental research fuelled my interest,” Kokko says. 

Kokko has noticed a waning enthusiasm among environmental engineering students for attending laboratory courses and pursuing doctoral degrees. 

“Technology students are starting their professional careers earlier than ever. With so many employment opportunities available outside academia, fewer students are seriously considering a research career,” Kokko points out. 

Kokko and her teacher colleagues have tackled this challenge by mounting a counter strike: they offer specifically tailored laboratory work opportunities for motivated students. 

Photo: Jonne Renvall, Tampereen yliopisto

Research supervision provides inspiration and insights

In recent years, conscious efforts have been made to encourage more women to pursue careers in technology. Women now make up approximately 50% of Kokko’s own research group. The international scientific community, in particular, needs experienced female researchers to set an example of successfully combining parenthood and an academic career. 

“Women can serve as role models in the international forums for environmental engineering. We even have an international network dedicated to women in this field that organises various activities, such as mentoring events,” she says. 

Kokko shares the view of many of her colleagues that a professorship enhances credibility. 

“A professorship means not only more responsibility but also more freedom to steer the direction of my research. It has also bolstered my confidence in my chosen research priorities.” 

Kokko finds the multidisciplinary approach and the dedication and enthusiasm of her colleagues to be the most rewarding aspects of working at Tampere University. She also enjoys teaching and supervising students working on their theses. 

“It is rewarding to support young, eager minds who have their entire careers ahead of them.”