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Removal of dissolved organic carbon and organic halide precursors by enhanced coagulation

dc.contributor.authorHargette, Paul Hudsonen
dc.contributor.committeechairKnocke, William R.en
dc.contributor.committeememberHoehn, Robert C.en
dc.contributor.committeememberDietrich, Andrea M.en
dc.contributor.departmentEnvironmental Engineeringen
dc.date.accessioned2014-03-14T21:43:52Zen
dc.date.adate2008-08-25en
dc.date.available2014-03-14T21:43:52Zen
dc.date.issued1997-06-06en
dc.date.rdate2008-08-25en
dc.date.sdate2008-08-25en
dc.description.abstractRaw water samples from nine utilities were received, and water-quality analyses, bench-scale water treatment, and chlorination were performed to determine the effectiveness of enhanced coagulation at removal of dissolved organic carbon (DOC) and organic halide precursors. Bench-scale treatment included: 1) baseline treatment, defined as the coagulant dose and pH at which the specific utility's water treatment plant was operating on the day the samples were collected, and 2) enhanced treatment, which was determined on the basis of bench-scale studies. Enhanced treatment is defined in the proposed Disinfectant/Disinfection By-Products (D/DBP) Rule as the coagulant dose at which a 10 mg/L increase in coagulant dose does not produce greater than a 0.3 mg/L decrease in dissolved organic carbon (DOC) or total organic carbon (TOC) concentration over the previous dose (Federal Register 1994). The treated samples were then chlorinated and analyzed for disinfection by-products (DBPs), including trihalomethanes (THMs) and non-purgeable dissolved organic halides (NPDOX). Specific objectives included: 1) an evaluation of the effectiveness of enhanced coagulation for TOC reduction, 2) determination of the effectiveness of surrogate parameters: such as raw water DOC and specific ultraviolet absorbance (SUVA); for predicting TOC removal by enhanced coagulation, and 3) determination of the relationship between DOC and NPDOX concentration in raw and treated waters. For all of the utilities, enhanced coagulation was effective at meeting the proposed TOC removal requirements contained in the D/DBP Rule, which range from 20 percent to 50 percent removal based on the alkalinity and TOC of the raw water. Raw water SUVA was the best indicator of the expected Toe removal by enhanced coagulation, with raw water SUVA values > 3.0 L/mg-m typically indicating greater TOC removal. Organic content was a good indicator of DBP formation. The average non-purgeable dissolved organic halogen formation potential (NPDOXFP) yields, based on DOC, were 155 μg as Cl⁻/mg DOC for raw water samples and ranged from 110- 138 μg as CI⁻/mg DOC for treated water samples.en
dc.description.degreeMaster of Scienceen
dc.format.extentxxviii, 339 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-08252008-162839en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-08252008-162839/en
dc.identifier.urihttp://hdl.handle.net/10919/44448en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1997.H374.pdfen
dc.relation.isformatofOCLC# 37744504en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectdissolved organic carbonen
dc.subjectdisinfection by-productsen
dc.subjectcoagulationen
dc.subject.lccLD5655.V855 1997.H374en
dc.titleRemoval of dissolved organic carbon and organic halide precursors by enhanced coagulationen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineEnvironmental Planningen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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