Water Research, Feb 1, 2014, Vol.49, p.144(13)
To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.watres.2013.11.003 Byline: Valentin Pfeiffer, Benoit Barbeau Abstract: Despite its shortcomings, the T10 method introduced by the United States Environmental Protection Agency (USEPA) in 1989 is currently the method most frequently used in North America to calculate disinfection performance. Other methods (e.g., the Integrated Disinfection Design Framework, IDDF) have been advanced as replacements, and more recently, the USEPA suggested the Extended T10 and Extended CSTR (Continuous Stirred-Tank Reactor) methods to improve the inactivation calculations within ozone contactors. To develop a method that fully considers the hydraulic behavior of the contactor, two models (Plug Flow with Dispersion and N-CSTR) were successfully fitted with five tracer tests results derived from four Water Treatment Plants and a pilot-scale contactor. A new method based on the N-CSTR model was defined as the Partially Segregated (Pseg) method. The predictions from all the methods mentioned were compared under conditions of poor and good hydraulic performance, low and high disinfectant decay, and different levels of inactivation. These methods were also compared with experimental results from a chlorine pilot-scale contactor used for Escherichia coli inactivation. The T10 and Extended T10 methods led to large over- and under-estimations. The Segregated Flow Analysis (used in the IDDF) also considerably overestimated the inactivation under high disinfectant decay. Only the Extended CSTR and Pseg methods produced realistic and conservative predictions in all cases. Finally, a simple implementation procedure of the Pseg method was suggested for calculation of disinfection performance. Author Affiliation: Industrial NSERC Chair on Drinking Water, Civil, Geological and Mining Engineering Dept., Polytechnique Montreal, CP 6079, Succ. Centre-Ville, Montreal, Quebec, Canada H3C 3A7 Article History: Received 12 July 2013; Revised 30 October 2013; Accepted 3 November 2013
Tracers (Chemistry) -- Methods ; Tracers (Chemistry) -- Analysis ; Infection Control -- Methods ; Infection Control -- Analysis
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