The Effect of Dissolved Ozone On The Corrosion Behavior of Heat Exchanger Structural Materials. Biocidal Efficacy On Bacterial Films

摘要

To assess the effect of ozone dissolved in syntheticcooling water on the corrosion behavior of different heatexchanger structural materials (stainless steel; 70:30 copper-nickel;aluminum brass and titanium), different electrochemicaltechniques were used. Voltamperometric experiments andcorrosion potential vs. Time measurements were made at ozoneconcentrations between 0.1 and 1.2ppm.the passive behavior of stainless steel and titanium is not affectedby dissolved ozone whereas copper alloys are susceptible tocorrosion in the presence of ozone.To study the biocidal action of various concentrations of dissolvedozone against planktonic and sessile bacteria, liquid cultures andbiofilms of Pseudomonas fluorescens, formed on different heatexchanger structural materials were used at different contact times.Dissolved ozone is an effective biocide for controlling planktoniccells but its effectiveness polymeric matrix of the biofilm. It issuggested that the penetration of ozone through the biofilmdepends on the simultaneous diffusion and reaction of the biocidewith the biofilm matrix which may exhibit local differences inbiomass distribution and hydrodynamic conditions.