Bromate removal in water through electrochemical reduction using Magnéli phase titanium oxide electrode

Area of Science:

• Environmental Chemistry
• Materials Science
• Electrochemistry

Background:

• Bromate is a harmful disinfection byproduct in drinking water.
• Effective treatment methods for bromate are crucial for public health.
• Electrochemical methods offer a promising avenue for water remediation.

Purpose of the Study:

• To investigate the electrochemical degradation of bromate using Magnéli phase titanium oxide (Ti4O7) electrodes.
• To optimize degradation efficiency by varying voltage, electrolyte concentration, and pH.
• To assess the stability and reusability of the developed electrodes for practical applications.

Main Methods:

• Fabrication of sheet electrodes and reactive membranes from Magnéli phase titanium oxide (Ti4O7).
• Electrochemical treatment experiments with varying operational parameters (voltage, electrolyte concentration, pH).
• Analysis of bromate removal efficiency and identification of degradation pathways.
• Evaluation of the impact of coexisting ions and application to secondary effluent wastewater.

Main Results:

• Achieved over 95% bromate removal using Ti4O7 electrodes.
• Optimized conditions (higher voltage, electrolyte concentration, lower pH) significantly enhanced degradation.
• Identified both direct and indirect electrochemical pathways for bromate reduction.
• Demonstrated 70% bromate degradation in secondary effluent within six hours.
• Found negligible inhibition by coexisting ions at 1 mM, but significant inhibition at 10 mM (SO4^2- > CO3^2- > Cl- ≈ NO3- ≈ NO2- > ClO4-).

Conclusions:

• Magnéli phase titanium oxide (Ti4O7) is a highly effective material for electrochemical bromate degradation.
• The electrochemical process is efficient and adaptable to real-world wastewater treatment.
• The electrodes exhibit excellent stability and reusability, confirming their potential for sustainable water treatment.