Efficiacy of activated PMS/PDS by different methods in inactivating E.coli and P.aeroginosa
Abstract
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 (K 2 S 2 O 8 , Na 2 S 2 O 8 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 K 2 S 2 O 8 , Na 2 S 2 O 8 , 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 K 2 S 2 O 8 (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 .