title: Experimental Testing of Water Disinfection Models under Varying Hydraulic and Kinetic Conditions.
abstract: The concomitant effects of hydraulics and reaction kinetics on the disinfection efficiency (DE) of Chlorine Contact Tank (CCT) setups were experimentally assessed, to test the predictive-ability of first order kinetics models: Chick-Watson (C-W), C-t rule and Wehner-Wilhelm (W-W). Prototype tests were conducted using river water characterised for quality parameters, chlorine demand and inactivation rates of total and thermotolerant coliform. Poor, average and superior CCT baffling conditions were assessed by tracer experimentation and for their DE under three chlorine dosages. The models' DE predictive-ability was comparable and high for superior baffling, but decreased differently with the hydraulic efficiency (maximum errors of +15.3% with W-W, +26.0% with C-W and -36.6% with C-t). The positive bias shown by W-W renders it unsafe for CCT design, so the results favoured the C-t rule as the preferred analytical tool of comparable complexity. Potential refinements to these models that could lead to operational savings are identified.
authors.affiliation: LabGest - Laboratory of Water Resources Management and Regional Development, Federal University of Espírito Santo (UFES), Vitória/ES, 29075-910, Brazil.
authors.forename: Edmilson C
authors.initials: EC
authors.lastname: Teixeira
authors.forename: William B
authors.initials: WB
authors.lastname: Rauen
authors.forename: Ismênia
authors.initials: I
authors.lastname: Fonseca
authors.forename: Iene
authors.initials: I
authors.lastname: Figueiredo
mesh_terms: D002713:Chlorine / Q000494:pharmacology*; D004202:Disinfectants / Q000494:pharmacology*; D004203:Disinfection / Q000379:methods*; D004755:Enterobacteriaceae / Q000187:drug effects*; D005618:Fresh Water / Q000382:microbiology*; D062070:Hydrology; D007700:Kinetics; D008962:Models, Theoretical; D018508:Water Purification / Q000379:methods*
chemical_list: D004202:Disinfectants; D002713:Chlorine