Efficacy of activated PMS/PDS by different methods in inactivating E.coli and P.aeroginosa

Abstract The aim of the present study was to evaluate to efficacy of peroxydisulfate(PDS)/peroxymonosulfate(PMS) activated by different methods in inactivating E.coli and P.aeruginosa. The UV-A, UV-A/PDS or PMS and NaOH/PDS processes were used to inactivate E.coli and P.aeruginosa. Three different sulfate salts (K2S2O8, Na2S2O8 and Oxone) were used to activate with UV-A radiation and the inactivation effects were determined. During 30 minutes of UV A radiation, the addition of 3 mM K2S2O8, Na2S2O8, and Oxone increased the removal efficiency of E. coli by 1.76, 1.51, and 2.47 log, respectively. For P. aeruginosa, there was an increase of 1.44, 1.62, and 2.55 logs, respectively. The highest removal efficiency was obtained with oxone + UV-A on E.coli and P.aeroginosa. In order to examine the inactivation effect of alkaline (NaOH) activated peroxydisulfate on microorganisms, studies were carried out using two different doses of K2S2O8 (2 and 3 mmol/L). With the increase of PDS concentration, the removal efficiency for both bacteria increased. Higher removal efficiency was obtained at high base/PDS ratios. When the PDS concentration is increased from 2mM to 3mM at the same NaOH/PDS (0.25) ratio, the time required for 4 log bacteria removal is reduced by 33% for E.coli, while there is a decrease of more than 44.2% for P.aeroginosa.