Understanding the sustainability niche of continuous flow tubular microbial fuel cells on beef packing wastewater treatment

Beef packing industry consumes a large amount of water and energy to support its production. To transform this industry to be more sustainable, the produced wastewater from a Midwestern beef packing plant was treated by a bench-scale tubular microbial fuel cell (MFC) in continuous fed mode in present study. When the MFC was fed with 1 g L⁻¹ beef extract solution, a maximum current density of 8.8 ± 0.2 A m⁻³ and organics removal of 28.2 ± 5.9% were observed. Switching feeding solution to real beef packing wastewater did not change system performance considerably. The current density achieved was 8.4 ± 0.2 A m⁻³ and the organics removal was 35.9 ± 9.7%. Life cycle assessment (LCA) results on operational phase showed that the environmental impact of produced electricity from MFC is minimal compared to the overall electricity consumption. Comparing to the existing on-site treatment infrastructures, adding MFC could reduce global warming by 36%. Also, integrating MFC into the existing on-site wastewater treatment will be less beneficial for fossil fuel depletion due to the less biogas produced, leading to higher requirement of natural gas utilization for heating purpose. The attractiveness of adding alternative energy producing treatment systems to food processors may be based on biogas production and use patterns.