Electrochemical Disinfection of Simulated Ballast Water Using RuO₂-TiO₂/Ti Electrode

Area of Science:

• Electrochemistry
• Environmental Science
• Microbiology

Background:

• Ballast water poses a significant risk for invasive species and pathogen transport.
• Electrochemical methods offer a promising alternative for ballast water treatment.
• Disinfection efficacy is influenced by operational parameters like salinity and current density.

Purpose of the Study:

• To investigate the electrochemical disinfection of ballast water using a RuO2-TiO2/Ti electrode.
• To evaluate the impact of varying NaCl concentrations and current densities on Escherichia coli inactivation.
• To determine the energy efficiency of the electrochemical treatment process.

Main Methods:

• Batch tests were performed using simulated ballast water contaminated with Escherichia coli.
• The study examined NaCl concentrations of 1%, 2%, and 3% (w/v).
• Current densities ranging from 0.3 to 3.0 mA/cm2 were applied to assess inactivation rates.

Main Results:

• Increased NaCl concentration and current density led to higher disinfection efficiency.
• Complete inactivation of E. coli was achieved within 1-2 minutes at 3% NaCl with current densities of 0.3-1.0 mA/cm2.
• Energy consumption for 100% inactivation ranged from 2.8 to 2.9 Wh/m3, which is lower than reported in previous studies.

Conclusions:

• Electrochemical disinfection with a RuO2-TiO2/Ti electrode is an effective method for treating ballast water.
• The process meets the International Maritime Organization's D-2 standard for ballast water quality.
• Optimized conditions of salinity and current density allow for rapid and energy-efficient E. coli inactivation.