Titanium Oxide Nanotube Based Point of Use Electrocatalytic Devices for Efficient Disinfection of Gram-Positive and Gram-Negative Bacteria

Abstract

Biological pathogens in our water supplies are becoming increasingly resistant to commercial disinfectants. Conventional water disinfection technologies including chlorination, ozonation and UV-ray have disadvantages such as they cannot be used for decentralized point-of-use water treatment system and produce hazardous disinfection by-products. These issues can be solved by using electrocatalyst TiO2 nanotubes-based devices that have been extensively studied for their photocatalytic applications. In this study we develop a point-of-use disinfection device for efficient electrochemical disinfection of both gram-positive (staphylococcus aureus) and gram-negative (E. coli) bacteria. These devices produce aqueous radicals under only a small applied voltage, the defects within the crystalline structure of the reduced titanium oxide nanotubes (NTs) contribute to the continuous electronic exchange with species in the electrolyte solution causing high rate of disinfection. The production of an oxidizing titania surface under an anodic bias provides a path way for continuous and controlled disinfection of biological pathogens under different biological environments. A series of electrochemial tests helped in evaluating the stability, lifetime and operating conditions for safe and efficient operation of these devices.