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dc.contributor.authorMartin, Amanda Kristineen_US
dc.date.accessioned2012-11-02en_US
dc.date.accessioned2014-03-14T20:43:48Z
dc.date.available2012-11-02en_US
dc.date.available2014-03-14T20:43:48Z
dc.date.issued2012-08-06en_US
dc.date.submitted2012-08-19en_US
dc.identifier.otheretd-08192012-202007en_US
dc.identifier.urihttp://hdl.handle.net/10919/34648
dc.description.abstractAssimilable organic carbon (AOC) is a suspected contributor to growth of microbes, including pathogens, in plumbing systems. Two phases of research were completed to improve knowledge of AOC and other forms of organic carbon in premise plumbing. In the first phase, the AOC Standard Method 9217B was compared to a new luminescence-based AOC in terms of time, cost, convenience, and sources of error. The luminescence method was generally more accurate, as it better captured the peak growth of the test organisms. It was also less expensive and less time-consuming. A few approaches to improving the accuracy of the method and detect possible errors were also presented. In the second phase of research, the possibility of AOC generation in premise plumbing was reviewed and then tested in experiments. It has been hypothesized that removal of AOC entering distribution systems might be a viable control strategy for opportunistic premise plumbing pathogens (OPPPs), but if AOC was generated in premise plumbing systems this approach would be undermined. Possible sources of AOC creation in premise plumbing, which is herein termed â distribution system derived biodegradable organic carbon (DSD-BDOC),â include: leaching of organic matter from cross linked polyethylene (PEX) pipes, autotrophic oxidation of H2 generated from metal corrosion (e.g. sacrificial magnesium anode rods and iron pipes), rendering of humic substances more biodegradable by sorption to oxides such as Fe(OH)3, and accumulation of AOC on filters and sediments. The potential for various plumbing and pipe materials to generate AOC was compared in controlled simulated water heater experiments. Under the worst-case condition, generation up to 645 µg C/L was observed. IT was not possible to directly confirm the biodegradability of the generated organic carbon, and there were generally no correlations between suspected generation of organic carbon and either heterotrophic plate counts (HPC) or of bacterial 16S rRNA genes. DSD-BDOC was also explored in a simulated distribution system with two disinfectant types (chlorine and chloramine) and three pipe materials (PVC, cement, and iron). TOC increased with water age, probably due to leaching of organics from PVC and possibly the aforementioned DSD-BDOC due to autotrophic reactions of nitrifiers and iron-related bacteria. As before, relationships between the higher levels of organic carbon and either HPC or 16S were not observed.en_US
dc.publisherVirginia Techen_US
dc.relation.haspartMartin_AK_T_2012.pdfen_US
dc.rightsI 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 Virginia Tech 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.subjectdistribution system derived biodegradable dissolveen_US
dc.subjectopportunistic premise plumbing pathogensen_US
dc.subjectassimilable organic carbonen_US
dc.titleOrganic Carbon Generation Mechanisms in Main and Premise Distribution Systemsen_US
dc.typethesisen_US
dc.contributor.departmentEnvironmental Sciences and Engineeringen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
dc.contributor.committeechairEdwards, Marc A.en_US
dc.contributor.committeememberPruden-Bagchi, Amy Jillen_US
dc.contributor.committeememberFalkinham, Joseph O. IIIen_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08192012-202007/en_US


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