Improved azo dye decolorization in a modified sleeve-type bioelectrochemical system.

Area of Science:

• Environmental Science
• Electrochemistry
• Wastewater Treatment

Background:

• Recalcitrant pollutants in wastewater pose environmental challenges.
• Bioelectrochemical systems (BES) offer a promising approach for pollutant removal.
• Optimizing BES configuration is crucial for practical applications.

Purpose of the Study:

• To develop and evaluate a novel sleeve-type bioelectrochemical system (BES) for efficient azo dye decolorization.
• To investigate the impact of the modified BES configuration on pollutant removal efficiency.
• To analyze the electrochemical performance and internal resistance of the sleeve-type BES.

Main Methods:

• Modification of a standard BES into a compact sleeve-type configuration.
• Utilizing an abiotic cathode for azo dye (Acid Orange 7, AO7) degradation.
• Employing electricigens in the anode chamber to oxidize acetate and supply electrons.
• Conducting decolorization experiments at varying AO7 concentrations (0.14–2.00 mM).
• Performing electrochemical impedance spectroscopy (EIS) to analyze internal resistance.

Main Results:

• Achieved over 98% decolorization efficiency for AO7.
• Demonstrated complete decolorization of AO7 within the tested concentration range.
• The sleeve-type configuration resulted in reduced internal resistance (anode: 26.4 Ω, cathode: 38.3 Ω, whole cell: 64.6 Ω).
• Enhanced performance attributed to the large electrode area and small inter-electrode distance.

Conclusions:

• The sleeve-type BES configuration significantly improves decolorization efficiency for recalcitrant pollutants.
• This configuration offers a highly effective and potentially scalable solution for azo dye removal from wastewater.
• This study represents the first application of a sleeve-type configuration for efficient azo dye decolorization using an abiotic cathode BES.