Cost-effective copper removal by electrosorption powered by microbial fuel cells

Area of Science:

• Environmental Science
• Electrochemistry
• Wastewater Treatment

Background:

• Copper (Cu(2+)) contamination in wastewater poses environmental risks.
• Conventional wastewater treatment methods often require external energy input.
• Microbial fuel cells (MFCs) offer a potential sustainable solution for wastewater treatment.

Purpose of the Study:

• To investigate the efficacy of a novel microbial fuel cell-sorption (MFC-sorption) process for cost-effective Cu(2+) removal from wastewater.
• To explore the impact of operational parameters on Cu(2+) removal efficiency and adsorption capacity.
• To elucidate the adsorption mechanism and kinetics of the MFC-sorption process.

Main Methods:

• Electrosorption driven by microbial fuel cells (MFCs) was employed for Cu(2+) removal.
• System parameters including electrolyte concentration, solution pH, MFC configuration (series), and initial Cu(2+) concentration were varied.
• Adsorption isotherms and kinetics were analyzed, and electrode materials (active carbon fibers - ACFs) were characterized.

Main Results:

• Optimal Cu(2+) removal was achieved at low electrolyte concentration and high solution pH.
• Adsorption capacity increased with more MFCs in series and higher initial Cu(2+) concentrations.
• Monolayer adsorption dominated, and higher initial Cu(2+) concentrations accelerated the adsorption rate. Electrode analysis revealed Cu2O and Cu formation.

Conclusions:

• MFC-sorption is a viable, energy-independent technology for removing Cu(2+) from wastewater.
• The process is influenced by solution chemistry and MFC configuration.
• MFC-sorption involves a combination of adsorption and electrochemical reduction (redox reactions).