Kinetics of adenovirus type 2 inactivation with free chlorine.
The objective of this study was to elucidate the effects of pH, temperature, and other relevant water quality parameters on the kinetics of adenovirus serotype 2 inactivation with free chlorine. Over a pH range of 6.5-10, a temperature range of 1-30 degrees C, and in a variety of water types, free chlorine was highly effective against adenovirus type 2. Its disinfection efficacy decreased with increasing pH and decreasing temperature, yet was unaffected by hardness and buffering species. Under the most challenging conditions investigated in this study (pH 10, 1 degrees C), a four-log reduction of adenovirus viability would be achieved at a CT value of 2.6mgCl(2)min/L. The inactivation kinetics was characterized by three phases of inactivation under most conditions. The first phase resulted from a reaction involving primarily the hypochlorous acid species and was characterized by rapid inactivation of viruses to a limit that increased with decreasing pH and increasing temperature. After reaching this limit, adenovirus exhibited two subsequent phases of inactivation at lesser rates that were not affected by temperature or pH. As with the first phase of kinetics, a limit of inactivation was approached in the second phase that decreased with increasing pH, and after which the kinetics was characterized by a third and final phase. An inactivation model consistent with these observations was found to provide adequate representation for the free chlorine inactivation of adenovirus serotype 2 as well as that reported in the literature for other adenovirus serotypes.
Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, 205 N. Mathews Ave., Urbana, IL 61801, USA; Ctr. of Advanced Materials for the Purification of Water with Systems (WaterCAMPWS), 1206 W. Green St., Urbana, IL 61801, USA.
Martin A
MA
Page
Joanna L
JL
Shisler
Benito J
BJ
Mariñas
D000256:Adenoviridae / Q000187:drug effects*; D002713:Chlorine / Q000494:pharmacology*; D004202:Disinfectants; D004305:Dose-Response Relationship, Drug; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D038301:Virus Inactivation / Q000187:drug effects; D014867:Water / Q000737:chemistry*; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
D004202:Disinfectants; D014867:Water; D002713:Chlorine