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Photoelectrocatalytic inactivation of E. coli XL‐1 blue colonies in water
Author(s) -
Philippidis N.,
Nikolakaki E.,
Sotiropoulos S.,
Poulios I.
Publication year - 2010
Publication title -
journal of chemical technology and biotechnology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.64
H-Index - 117
eISSN - 1097-4660
pISSN - 0268-2575
DOI - 10.1002/jctb.2394
Subject(s) - photocatalysis , reaction rate constant , electrode , electrochemistry , materials science , annealing (glass) , semiconductor , nuclear chemistry , kinetics , nanotechnology , chemical engineering , chemistry , analytical chemistry (journal) , catalysis , chromatography , optoelectronics , biochemistry , composite material , physics , quantum mechanics , engineering
BACKGROUND: The aim of the present work was the preparation of TiO 2 P‐25 working electrodes on Ti substrates (TiO 2 /Ti), their characterization and the study of their photoelectrocatalytic activity towards the inactivation of E. coli XL‐1blue (E. Coli) colonies, used as model pathogenic bacteria, in a novel batch photoelectrochemical reactor. RESULTS: After annealing of the TiO 2 /Ti specimens at 500 °C, the surface morphology and crystal structure of the TiO 2 film electrodes were examined by scanning electronic microscopy (SEM) and X‐ray diffraction (XRD), while from differential capacitance measurements the flat band potential was calculated ( V fb = − 0.54 V versus Ag/AgCl). The results of photoelectrocatalytic (PEC) experiments concerning the disinfection of E. coli colonies were compared with those of electrochemical (EC) and photocatalytic (PC) inactivation of the pathogen and showed a significant synergy effect in the case of PEC disinfection, leading, at + 1.0 V vs Ag/AgCl cell voltage, to a 100% increase of the apparent rate constant, k o , in comparison with the simple photocatalytic process. Reuse experiments showed that the working electrode retains its effectiveness after, at least, 15 times of reuse. CONCLUSIONS: The photoelectrocatalytic inactivation of E. coli colonies has been studied under artificial illumination in a novel photoelectrocatalytic reactor. The inactivation of 10 3 CFU mL −1 E. coli colonies followed first‐order kinetics, while parameters such as type of semiconductor and concentration of the microorganisms play an important role affecting the reaction rate constant. Copyright © 2010 Society of Chemical Industry