A core theme of my PhD research was developing electrochemical methods for disinfecting water without added chemicals, particularly for low ionic strength media similar to potable water.
Using platinized titanium electrodes, I investigated the mechanisms underlying electrochemical inactivation of Escherichia coli, with a focus on the role of reactive oxygen species generated at the electrode surface. A comparative study between two-electrode and three-electrode cell configurations showed that the three-electrode setup achieved higher current throughput and improved bacterial inactivation, owing to the potentiostat’s ability to compensate for solution resistance (IR drop) via the reference electrode 1.
Inactivation followed pseudo-first-order (logarithmic decay) kinetics across the electrolytes tested, with sodium chloride showing enhanced bactericidal activity attributed to in situ generation of chlorine species.
This experimental work builds on a broader review of electrode and electrolyte choices for small-scale, decentralized water treatment — comparing chemical-free approaches (e.g., Magnéli-phase electrodes) against iodine-mediated electrochemical disinfection systems 2.
My role: Lead researcher — experimental design, electrochemistry, and manuscript preparation, under the supervision of Assoc Prof Richard D. Webster (NTU).
References
2025
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Electrochemical inactivation of Escherichia coli using platinized titanium electrodes: a comparison between two- and three-electrode configurations
Panyawut Tonanon and Richard D. Webster
Journal of Solid State Electrochemistry, Mar 2025
This study explores the feasibility of using platinized titanium electrodes for the electrochemical inactivation of Escherichia coli (E. coli), with the aim of developing an efficient and sustainable water disinfection method in low ionic strength media similar to what exists in potable water. A comparative analysis between two-electrode and three-electrode configurations revealed the superiority of the three-electrode system in achieving higher current throughput and enhanced bacterial inactivation efficiency. This improvement is attributed to the potentiostat’s ability to compensate for solution resistance (IR drop) through the inclusion of the reference electrode, ensuring more stable and controlled electrochemical conditions. The inactivation of E. coli in various electrolyte solutions followed a logarithmic decay pattern (pseudo first-order), with no significant difference observed among the electrolytes tested, except for sodium chloride. The enhanced bactericidal activity in the presence of NaCl was attributed to the generation of chlorine species. These findings provide insights into optimizing electrochemical disinfection systems and highlight the potential of three-electrode configurations for practical water treatment applications in low-conductivity environments.
2023
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Recent electrode and electrolyte choices for use in small scale water treatment applications—A short review
Panyawut Tonanon and Richard D. Webster
Current Opinion in Electrochemistry, Apr 2023
Boron-doped diamond and titanium suboxides have been proposed as electrode materials for use as anodes in future electrochemical devices, most likely in remote locations for potable water purification, or for specialized disinfection applications in decentralized systems. A comparison is made between electrochemical purification strategies that do not require added chemicals and systems that do, with emphasis given toward Magnéli electrode-based electrochemical disinfection and iodine-based electrochemical disinfection systems. Both systems with and without added chemicals come with advantages and disadvantages. The outlook of these emerging processes concludes this review.