Comparison of complex effluent treatability in different bench scale microbial electrolysis cells

Area of Science:

• Environmental Engineering
• Biotechnology
• Electrochemistry

Background:

• Microbial electrolysis cells (MECs) are advanced systems for wastewater treatment and energy recovery.
• Scaling up MECs from laboratory to industrial applications requires reliable predictive models.
• Miniaturized MECs (mini MECs) offer a potential solution for efficient performance prediction.

Purpose of the Study:

• To evaluate the efficacy of mini MECs in predicting the performance of larger-scale cube MECs.
• To assess the applicability of mini MECs for screening diverse wastewater sources for treatment potential.
• To compare COD removal, coulombic efficiency, and current generation between mini and cube MECs.

Main Methods:

• Wastewater and substrate samples were analyzed using mini MECs and compared with larger cube MECs.
• Key performance indicators such as Chemical Oxygen Demand (COD) removal and coulombic efficiency were measured.
• Current generation and hydrogen recovery were monitored across different wastewater types.

Main Results:

• Mini MECs demonstrated good correlation with cube MECs for COD removal (66-92%) and coulombic efficiency.
• Current generation consistency varied between reactor types, particularly for industrial and domestic wastewaters.
• Hydrogen recovery was observed in cube MECs, with significant variations in gas composition and volume.
• Direct conversion of substrate to methane was observed in specific industrial wastewater samples.

Conclusions:

• Mini MECs serve as a valuable and reliable platform for screening wastewater sources for treatment efficiency.
• The data from mini MECs can accurately predict the performance of larger-scale MEC reactors.
• This approach facilitates the selection of suitable wastewaters for MEC-based treatment processes.