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dc.contributor.authorDauphinais, Jennifer L.en_US
dc.date.accessioned2014-03-14T21:36:34Z
dc.date.available2014-03-14T21:36:34Z
dc.date.issued2003-04-23en_US
dc.identifier.otheretd-05232003-204831en_US
dc.identifier.urihttp://hdl.handle.net/10919/42779
dc.description.abstractUpset events due to the inflow of toxic chemicals are a critical issue for wastewater treatment facilities. Understanding the source-effect relationship of toxic chemicals can facilitate the prevention or improved reaction to upset events. Part one of this study was conducted to investigate the source of upset events at a regional industrial wastewater treatment plant (WWTP). Part two of this study determined the process performance effects of two chemical shocks, cyanide (zinc-cyanide complex) and pH, on nitrifying and non-nitrifying activated sludge. A modified respirometric assay protocol was developed to allow the industrial WWTP to screen industrial wastewaters for inhibitory properties. All five industrial wastewaters tested revealed inhibitory properties. Large day-to-day variations were found, illustrating the need for a large database of results for comparison over time. Additionally, a small volume contributor, that was thought by the utility to be an unlikely source of problems, contributed significantly to the wastewater oxygen demand and demonstrated inhibitory properties. The modified respirometric procedure enabled the WWTP to identify possible industrial sources that could cause an upset event. Lab-scale sequencing-batch reactors were used to determine the effects of cyanide and pH shock on activated sludge. Three reactors were shocked with increasing weak-acid complexed zinc cyanide or pHs of 5, 9, and 11. The resulting effects were compared to an un-shocked control reactor. It was found that respiration and nitrification were affected by the zinc cyanide complex, while COD removal, effluent TSS and dewaterability were not. Recovery was seen in less than 2 X solids residence time (SRT) for the nitrifying biomass and within 3 X SRT for the non-nitrifying biomass. The results of the pH experiment showed that the pH 11 shock affected the settleability, nitrification, COD removal, and effluent TSS levels of the reactors, while pH 5 and pH 9 shocks had no effect. Recovery was seen within 3 X SRT for both the nitrifying and non-nitrifying systems.en_US
dc.publisherVirginia Techen_US
dc.relation.haspart07AppendixF.PDFen_US
dc.relation.haspart04AppendixC.PDFen_US
dc.relation.haspart05AppendixD.PDFen_US
dc.relation.haspart03AppendixB.PDFen_US
dc.relation.haspart02AppendixA.PDFen_US
dc.relation.haspart01Thesis.PDFen_US
dc.relation.haspart06AppendixE.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.subjectrespirationen_US
dc.subjectcyanideen_US
dc.subjectpHen_US
dc.subjecttoxicityen_US
dc.subjectActivated sludgeen_US
dc.titleEvaluating the Source-Effect Relationship of Industrial Toxins in Wastewater Treatmenten_US
dc.typeThesisen_US
dc.contributor.departmentEnvironmental Engineeringen_US
dc.description.degreeMaster of Scienceen_US
thesis.degree.nameMaster of Scienceen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineEnvironmental Planningen_US
dc.contributor.committeechairLove, Nancy G.en_US
dc.contributor.committeememberLittle, John C.en_US
dc.contributor.committeememberNovak, John T.en_US
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-05232003-204831/en_US
dc.date.sdate2003-05-23en_US
dc.date.rdate2004-07-10
dc.date.adate2003-07-10en_US


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