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dc.contributor.authorZhu, Kuangen_US
dc.date.accessioned2013-06-11T08:00:24Z
dc.date.available2013-06-11T08:00:24Z
dc.date.issued2013-06-10en_US
dc.identifier.othervt_gsexam:1271en_US
dc.identifier.urihttp://hdl.handle.net/10919/23192
dc.description.abstractFats, oil and grease (FOG) are generated in large amounts by cooking and food processing. Anaerobic co-digestion with municipal sewage sludge has proven to be one of best alternatives for FOG disposal due to its high potential for biogas production. However, excessive addition of long chain fatty acid, the major content of FOG, has been reported to have inhibitory effects on the anaerobic digestion process and to cause operational challenges. In this study, high purity long chain fatty acids (LCFAs) including linoleic acid, oleic acid, and a mixture of oleic acid and stearic acid were added to laboratory completed mixed anaerobic digesters. The performance of the digesters in terms of solids destruction, COD degradation, LCFAs accumulation and gas production was investigated. After reaching steady state, a large amount of palmitic acid was found in the reactors with oleic acid addition and mixture of stearic and oleic acid addition. In the meantime, no palmitic acid increase was observed in reactors where linoleic acid was added. A better solids and COD reduction and a higher biogas production were observed in reactors with higher LCFAs addition. For reactors with the same dosage of LCFAs addition, linoleic acid addition resulted in the greatest improvement in digester performance; the mixture of stearic acid and oleic acid achieved the least increase in biogas production and solids and COD reduction. A high concentration of both palmitic and stearic acid in the reactors with oleic acid addition and with 20% mixed acid addition was observed. In contrast, linoleic acid and 30% mixed acid addition did not lead to a greater palmitic or stearic acid concentrations. Up to 30% of pure linoleic acid, oleic acid and mixed acid addition are able to enhance the performance of anaerobic digesters. It is recommended that the dosage of oleic acid be below 30% to avoid LCFAs accumulation and to increase reactor stability.en_US
dc.format.mediumETDen_US
dc.publisherVirginia Techen_US
dc.rightsThis Item is protected by copyright and/or related rights. Some uses of this Item may be deemed fair and permitted by law even without permission from the rights holder(s), or the rights holder(s) may have licensed the work for use under certain conditions. For other uses you need to obtain permission from the rights holder(s).en_US
dc.subjectAnaerobic digestionen_US
dc.subjectFatsen_US
dc.subjectoil and greaseen_US
dc.subjectLong chain fatty acidsen_US
dc.subjectbiogas productionen_US
dc.subjectEnergy Recoveryen_US
dc.subjecten_US
dc.titleEffect of Long Chain Fatty Acids on Anaerobic Digestion of Municiapal Sewage Sludge in Completely Mixed Reactorsen_US
dc.typeThesisen_US
dc.contributor.departmentCivil and Environmental Engineeringen_US
dc.description.degreeMSen_US
thesis.degree.nameMSen_US
thesis.degree.levelmastersen_US
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen_US
thesis.degree.disciplineCivil Engineeringen_US
dc.contributor.committeechairNovak, John Ten_US
dc.contributor.committeememberLittle, John Cen_US
dc.contributor.committeememberBoardman, Gregory Den_US


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