Performance evaluation of a microbial fuel cell for resource recovery as struvite and bioelectricity generation from slaughterhouse wastewater

BACKGROUND

The microbial fuel cell (MFC) is a potential cost-effective technology for the energy-neutral treatment of wastewater. However, the successful implementation of this technology in resource recovery is still limited. In this study, a microbial electrochemical cell was designed and operated for 30 days. Critical factors for removal and recovery of nitrogen and phosphorus as struvite from wastewater were assessed.

RESULTS

Optimization studies on critical factors such as the chemical oxygen demand (COD) of wastewater (500–2000 mg L⁻¹) and cathode aeration rate (45–135 mL min⁻¹) were conducted using a pure culture of Escherichia coli. The system yielded an average power density of 465 mW m⁻², average current density of 915 mA m⁻² and phosphorus recovery at an extent of 40% as struvite. Additionally, a maximum reduction in the COD of 90% with an average coulombic efficiency of about 82% was obtained at a short interval of 30 days. Solubility studies of the recovered struvite for 12 h at different pH values from 4.5 to 9 showed a maximum solubility of 80% at pH 4.5 and a minimum of 3.5% at pH 9.

CONCLUSION

This study moves one step closer to applying MFC technology for nitrogen- and phosphorus-rich wastewater treatment with concurrent struvite precipitation and electricity production. In this way, Sustainable Development Goals 2, 6 and 7 can be achieved through resource recovery, clean water and bioenergy. © 2024 Society of Chemical Industry (SCI).