Open Collections

Zafar, Hirra

University of British Columbia

Food waste generation is increasing due to a rise in the global population and their ever-increasing demands. If not appropriately treated, food waste can harm human health and the environment in many ways. Microbial fuel cells (MFCs) are bioelectrochemical systems with a great potential to oxidize organic matter present in food waste with simultaneous electricity generation. Previous MFC research has focused on treating simple wastewaters and improving power output. A limited amount of work has been done using solid feedstocks, with generally low reported performance. The goal of the present study was to solve challenges when treating solid fruit waste in MFCs using soft techniques such as meta-analysis and experimentally using lab-scale MFC prototypes. A systematic review (meta-analysis) of MFC studies highlighted the critical associations between MFC influence factors and response metrics. Results indicated that dual-chamber MFCs achieved 18% higher chemical oxygen demand removal and 73% higher coulombic efficiencies than single-chamber MFCs. A comparative analysis of the MFC design and operating phase was carried out on a lab scale by developing a two-stage anaerobic up-flow leachate reactor MFC (AULRMFC) and a single-stage MFC (SSMFC). The findings revealed that an AULRMFC with substrate recirculation successfully achieved 95% higher total solids removal in 30 days compared to SSMFC. The fruit waste degradation in MFC was also evaluated employing bioaugmentation with carbohydrate-degrading strains Bacillus subtilis and Cellulomonas fimi. The results demonstrated that adding Cellulomonas fimi alone resulted in the highest cellulose removal of 2,759 mg/L cellulose in two days. The addition of both Cellulomonas fimi and Bacillus subtilis achieved the highest total solids removal and total volatile solids removal of 82% and 84%, respectively. A seasonality study was conducted to analyze the influence of feedstock change on MFC efficiency. A 91% and 119% decline in COD removal efficiency and power density, respectively, was noticed when the feedstock was changed to cherry slurry. The decrease in power density and COD removal efficiency was attributed to the high internal resistance posed by cherry pits. The outcome of the present study revealed new information about MFCs that provides a clear pathway for future research in this field.

Text

2023-04-14

Attribution-NoDerivatives 4.0 International

http://hdl.handle.net/2429/84206

Civil Engineering

University of British Columbia

UBCO

http://creativecommons.org/licenses/by-nd/4.0/