Kinetic study of the effect of temperature on the cleaning and disinfecting actions of sodium hypochlorite
2009
Fukuzaki, S.(Okayama-ken. Industrial Technology Center (Japan)) | Urano, H. | Takahashi, K. | Yamada, S. | Takagi, A.
The kinetics of the actions of sodium hypochlorite (NaOCl) in removing bovine serum albumin (BSA) irreversibly adsorbed on stainless steel and in inactivating Pseudomonas fluorescens was studied at various temperatures. An NaOCl solution of pH 9 containing free available chlorine (AC) of 600mg/l was used as the cleaning solution, in which OHsup(-) ions exerted no significant cleaning action. The rate and efficiency of the BSA removal by the NaOCl solution increased with increasing temperatures from 20 to 60degC, beyond which they decreased gradually. The logarithmic relative reduction of viable P. fluorescens by NaOCl solutions of pH 5.7 and 7.6 containing 2.5 mg AC/l depended on the product of the AC concentration and time, and the rate of inactivation increased with increasing temperatures from 15 to 40degC. Both the first-order rate constants for removing BSA (ksup(OCl)) and inactivating P. fluorescens (ksup(HOCl)) showed an Arrhenius-type temperature dependence. The apparent activation energies (Esub(a)) for the ksup(OCl) and ksup(HOCl) values were estimated to be approximately 30 and 60 kJ/mol, respectively.
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