title: Effect of disinfectants on microbial ecology in model distribution systems.
abstract: This research was conducted to assess the impact of various disinfectants on bacterial water quality within model distribution systems (i.e. annular reactors). After colonization with non-disinfected water, annular reactors were treated with relatively low doses of chlorine (0.4 mg/l), chlorine dioxide (0.15 mg/l), or chloramines (0.9 mg/l). Under the tested conditions, bacterial inactivation varied as a function of disinfectant type (ranking by efficiency per mg of oxidant: ClO2 > Cl2 > ClNH2) and sample type (bulk water vs. biofilm). Depending on the disinfectant, the log inactivation of suspended and attached bacteria were 0.7-1.2 and 0.5-1.0, respectively. The characterization of microbial communities in drinking water can be performed using biochemical and/or molecular methods. In this study, biochemical tests were used, showing that pseudomonad and pseudomonad-like bacteria, as in other studies, were the most predominant micro-organisms (e.g. Pseudomonas fluorescens, Brevundimonas vescularis). The ratio Gram-positive to Gram-negative organisms was 1 to 3. No drastic differences were observed between the non-treated and disinfected pipes. Based on the bacteriological data presented in these experiments, chlorine dioxide represents an alternative to chlorine for certain distribution systems.
authors.affiliation: Indiana University- Kokomo, PO Box 9003, Kokomo, IN 46904, USA. cchauret@iuk.edu
authors.forename: C
authors.initials: C
authors.lastname: Chauret
authors.forename: C
authors.initials: C
authors.lastname: Volk
authors.forename: L
authors.initials: L
authors.lastname: Stover
authors.forename: T S
authors.initials: TS
authors.lastname: Dykstra
authors.forename: R C
authors.initials: RC
authors.lastname: Andrews
authors.forename: G A
authors.initials: GA
authors.lastname: Gagnon
mesh_terms: D001419:Bacteria / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects*; D002700:Chloramines; D002712:Chlorides / Q000494:pharmacology*; D017606:Chlorine Compounds / Q000494:pharmacology*; D015169:Colony Count, Microbial; D004202:Disinfectants / Q000494:pharmacology*; D010087:Oxides; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*; D014881:Water Supply
chemical_list: D002700:Chloramines; D002712:Chlorides; D017606:Chlorine Compounds; D004202:Disinfectants; D010087:Oxides; C025109:chlorine dioxide; C030816:chloramine