Economic potential of bioremediation using immobilized microalgae-based microbial fuel cells

The cathodic microalgae-based MFC converts the nutrients within wastewater and produces oxygen as oxygen supply for cathodic reactions, leading to the reduction of aeration cost. Continuous energy supplies are secured via the studied technology to solve overloaded nutrient and toxic substances discharge into environment, in a sustainable approach. Electricity and biomass produced are sellable as bioenergy and bioproducts, having the potential to generate more income compared to traditional MFC. As result, Chlorella sp. G29-5 has the best performance of nutrient removal, growth and electricity generation compared to other microalgae strains, using immobilized fructose sludge as anode. Immobilized anaerobic inoculum showed higher efficiency on electricity generation compared to suspended anaerobic inoculum. This technology has fully utilized bacteria from sludge and swine manure as microalgae nutrient and generating electricity as output. Cost estimation of other MFC has been included as a reference compared to the current technologies. The capital cost per power generated for this study is $490.46/mW, which is comparatively higher than other systems without concerning the extra income of microalgae biomass generated and nutrient recovered. Replacing expensive catalyst with microalgae is potential to reduce production cost required for MFC and treat wastewater, benefitting the wastewater treatment and power sectors. Consumption of nutrients by microalgae leads to efficient COD removal and aids in controlling severe soil and water pollution. Graphic abstract: [Figure not available: see fulltext.]