USE OF A TITANIUM NITRIDE FOR ELECTROCHEMICAL INACTIVATION OF MARINE-BACTERIA

A titanium nitride (TIN) electrode with very low resistance and good e lectrochemical stability was constructed and used for electrochemical inactivation of the marine Gramnegative bacterium Vibrio alginolyticus . Specific resistance of the TiN electrode, which was formed by reacti ve sputtering, was 1.1 x 10(-4) Omega . cm. When cyclic voltammetry of the TiN electrode-attached V. alginolyticus cells of 4.2 x 10(5) cell s/cm(2) was carried out at a scan rate of 20 mV/s in seawater, an anod ic peak current appeared around 0.68 V vs AS/AgCl. In all, 98.7% of V, alginolyticus cells attached onto the electrode were inactivated by a pplying a potential of 0.8 V vs Ag/AgCl in seawater for 30 min. Change s in pH and chlorine concentration were not observed at 0.8 V vs Ag/Ag Cl. The TIN electrode was oxidized by applying potential of a 0.8 V vs Ag/AgCl and passivated by formation of TiO2 onto the electrode surfac e. The TiO2 thin layer formed on the TiN electrode surface did not imp ede electrochemical inactivation of marine bacteria. These results sho w that the TiN electrode can be used as an electrode for electrochemic al inactivation of marine bacteria.