Acid-phase and Two-phase Codigestion of FOG in Municipal Wastewater

dc.contributor.authorVarin, Ross A. IIIen
dc.contributor.committeechairNovak, John T.en
dc.contributor.committeememberBoardman, Gregory D.en
dc.contributor.committeememberBott, Charles B.en
dc.contributor.departmentCivil and Environmental Engineeringen
dc.date.accessioned2013-06-12T08:01:16Zen
dc.date.available2013-06-12T08:01:16Zen
dc.date.issued2013-06-11en
dc.description.abstractAcidogenic codigestion of fats, oils, and greases (FOG) was studied at 37"C using suspended sludge digesters operated as sequencing batch reactors (SBRs). Volatile fatty acid (VFA) production was found to increase with larger FOG loading rates, although this increase was insignificant compared the theoretical VFA production from FOG addition. Long chain fatty acids (LCFAs) were found to have accumulated in the reactor vessel in semi-solid balls that were primarily composed of saturated LCFAs. Adding high FOG loadings to an APD not acclimated to LCFAs allowed for a mass balance calculation and resulted in near complete saturation of unsaturated LCFAs and significant accumulation of LCFA material in the digester, which was found to be mostly 16:0, 18:0, and 18:1. While 18:2 and 18:3 LCFAs were nearly completely removed, 18:0 and 14:0 LCFAs were produced, most likely from the degradation of 18:2 and 18:3 LCFAs. The APD pH was found to have a significant impact on the amount of accumulated LCFA material present, with higher pH levels resulting in less accumulated material. Two-phase codigestion of FOG was also studied using an APD followed by gas-phase (GPD) digesters. The two-phase systems were compared by FOG addition to the APD versus GPD. FOG addition to the APD resulted in 88% destruction of LCFAs, whereas FOG addition to the GPD resulted in 95% destruction of LCFAs. Accumulated LCFAs in the APD receiving FOG were composed mostly of stearic acid (18:0). The low pH of the APD is likely the cause of LCFA accumulation due to saturation of unsaturated LCFAs.en
dc.description.degreeMaster of Scienceen
dc.format.mediumETDen
dc.identifier.othervt_gsexam:1241en
dc.identifier.urihttp://hdl.handle.net/10919/23210en
dc.publisherVirginia Techen
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subjectCodigestionen
dc.subjecttwo-phase anaerobic digestionen
dc.subjectacid-phase anaerobic digestionen
dc.titleAcid-phase and Two-phase Codigestion of FOG in Municipal Wastewateren
dc.typeThesisen
thesis.degree.disciplineEnvironmental Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
Varin_RA_T_2013.pdf
Size:
752.01 KB
Format:
Adobe Portable Document Format

Collections