Evaluating Sequential Disinfection in a Water Treatment System Using a Non-biological Surrogate.

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dc.contributor.advisor Detlef R. U. Knappe, Committee Member en_US
dc.contributor.advisor Francis de los Reyes, Committee Member en_US
dc.contributor.advisor Joel Ducoste, Committee Chair en_US
dc.contributor.author Richards, Brannon Heath en_US
dc.date.accessioned 2010-04-02T18:13:00Z
dc.date.available 2010-04-02T18:13:00Z
dc.date.issued 2005-01-11 en_US
dc.identifier.other etd-12162004-151944 en_US
dc.identifier.uri http://www.lib.ncsu.edu/resolver/1840.16/2396
dc.description.abstract Fluorescent YG-microspheres (Polysciences Inc.) were evaluated to simulate Cryptosporidium inactivation in a flow-through system that utilizes multiple disinfectants. Experiments were performed in a disinfection process consisting of an ozone primary stage and a secondary free chlorine treatment stage. Impacts of the chemical disinfectant exposure were calculated by tracking the changes in fluorescence distribution with a flow cytometer. Microspheres were initially pretreated to reduce their fluorescence intensity to a level that would allow them to closely mimic Cryptosporidium. Microsphere survival ratios (N/No) were calculated by replicating the inactivation of Cryptosporidium observed by Driedger et al. [6] and selecting an appropriate fluorescence intensity threshold in a histogram analysis. The results from these flow-through experiments suggest that the fluorescence decay of YG-fluorescent microspheres does display synergistic effects when free chlorine is used sequentially with ozone. This study also included the use of numerical models to simulate sequential disinfection processes. Femlab 3.0a and the Segregated Flow Reactor method were used to evaluate sequential disinfection processes. These numerical models were set up to mimic the experimental conditions observed in this research. The sequential disinfection inactivation predicted in these models was similar to the experimental fluorescence decay of the microspheres. However, the models were not effective at predicting fluorescent intensity changes at different intermediate points within the disinfection process stream. en_US
dc.rights I hereby certify that, if appropriate, I have obtained and attached hereto a written permission statement from the owner(s) of each third party copyrighted matter to be included in my thesis, dissertation, or project report, allowing distribution as specified below. I certify that the version I submitted is the same as that approved by my advisory committee. I hereby grant to NC State University or its agents the non-exclusive license to archive and make accessible, under the conditions specified below, my thesis, dissertation, or project report in whole or in part in all forms of media, now or hereafter known. I retain all other ownership rights to the copyright of the thesis, dissertation or project report. I also retain the right to use in future works (such as articles or books) all or part of this thesis, dissertation, or project report. en_US
dc.subject modeling en_US
dc.subject microsphere en_US
dc.subject Cryptosporidium en_US
dc.subject disinfection en_US
dc.subject sequential en_US
dc.subject chlorine en_US
dc.subject ozone en_US
dc.title Evaluating Sequential Disinfection in a Water Treatment System Using a Non-biological Surrogate. en_US
dc.degree.name MS en_US
dc.degree.level thesis en_US
dc.degree.discipline Civil Engineering en_US


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