A review of the role of pre-treatment on the treatment of food waste using microbial fuel cells

ABSTRACT

Food waste is primarily managed by incineration or disposal in landfills. These current management methods can result in adverse environmental effects, are expensive, and do not necessarily take advantage of the remaining energy potential in food waste. Alternative treatment technologies such as microbial fuel cells (MFCs) are an attractive disposal method since overall organic concentrations can be reduced, and some of the chemical energy of the food waste can be transformed into electrical energy. MFC research has focused on the use of liquid waste due to advantages such as easy handling, low internal resistance, and efficiency of ion transfer in the liquid phase. While some researchers have shown the potential of using complex solid waste as a direct fuel in MFC, there remain significant challenges for optimizing complex solid food waste-fed MFCs. In particular, the biological degradation of the complex substrates in food waste is a slow process and requires additional pre-treatment (physical, thermal, chemical, or biological) to degrade complex biopolymers efficiently. As such, this article aims to review the impact and importance of various pre-treatment methods for optimizing performance of food waste fed MFCs. It is clear that direct use of solid waste in MFCs can be promising if several factors are optimized, including the pre-treatment used, substrate biodegradability, and operational cost. Although low power output is one of the main obstacles in the commercialization of MFC, MFC can still be considered a viable, self-sufficient treatment method to treat waste with minimum to zero emissions.

GRAPHICAL ABSTRACT

Keywords:

• Food waste
• degradation
• microbial fuel cell
• pre-treatments
• solid waste

Acknowledgements

We acknowledge Dr. Soheil Aber and Taiebeh Ahmadpour for their support during the initial writing process.

Contributor’s statement

HZ: Conceptualization, methodology, data curation, writing, original draft preparation NP: Supervision, reviewing and editing DR: Supervision, reviewing and editing

Data availability statement

Data will be made available upon reasonable request.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Funding statement

The research was funded by the Punjab educational endowment fund PEEF, Pakistan.

Additional information

Notes on contributors

Hirra Zafar

Hirra Zafar is a Ph.D. student of Civil Engineering at the University of British Columbia. Her Ph.D. work aims at sustainable management of food waste. She is currently working on treating fruit waste with simultaneous generation of electricity using microbial fuel cells. Her current research is focused on comparing reactor designs, pre-treatment options and other operational parameters to find the most sustainable and feasible MFC design.

Nicolas Peleato

Dr. Nicolás Peleato is an Assistant Professor in the School of Engineering at the University of British Columbia Okanagan. He earned his PhD from the University of Toronto in Civil Engineering, specializing in developing fluorescence-based monitoring methods for water treatment operations. Within his research group at UBC, Dr. Peleato's research group focuses on improving the control, monitoring, and efficiency of water treatment and environmental systems using data science.

Deborah Roberts

Deborah June Roberts received her B.Sc. and Ph.D. in microbiology from the University of Alberta in 1985 and 1990 respectively. She is currently the Dean of the Faculty of Science and Engineering at UNBC. Prior to joining UNBC, Dr. Roberts a Professor in the School of Engineering in UBC's Okanagan campus and prior to that was an Assistant then Associate Professor at the University of Houston, Houston TX. She has delivered numerous invited presentations, authored or coauthored more than 85 papers in peer-reviewed journals and conference proceedings as well as 2 issued patents and 7 book chapters. Dr Roberts' research focus is on applied microbiology, including the use of microbes to remove contaminants from soil and water as well as measuring microbes in the environment.