Enrichment of activated sludge in a sequencing batch reactor for polyhydroxyalkanoate production

The paper describes the start up of a process for the production of polyhydroxyalkanoates (PHAs) from activated sludge. The excess sludge from a wastewater treatment plant was inoculated in a lab-scale sequencing batch reactor (SBR) to be enriched under aerobic conditions through intermittent feedin...

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Détails bibliographiques
Publié dans:Water science and technology : a journal of the International Association on Water Pollution Research. - 1986. - 54(2006), 1 vom: 02., Seite 119-28
Auteur principal: Majone, M (Auteur)
Autres auteurs: Beccari, M, Di Gregorio, S, Dionisi, D, Vallini, G
Format: Article
Langue:English
Publié: 2006
Accès à la collection:Water science and technology : a journal of the International Association on Water Pollution Research
Sujets:Journal Article Research Support, Non-U.S. Gov't Alkanes Industrial Waste Sewage
Description
Résumé:The paper describes the start up of a process for the production of polyhydroxyalkanoates (PHAs) from activated sludge. The excess sludge from a wastewater treatment plant was inoculated in a lab-scale sequencing batch reactor (SBR) to be enriched under aerobic conditions through intermittent feeding with a mixture of organic acids. Enriching of activated sludge was monitored through the measurement of polymer concentrations either in the mixed liquor or in the microbial biomass. The bacterial population dynamics during the SBR start up was followed through denaturing gradient gel electrophoresis and the main species present at the steady state were identified. All the measured parameters significantly changed in the SBR during first two weeks after the inoculum was seeded into the reactor, they then stabilized. At the steady state, the SBR produced 2.6 gVSSl(-1) d(-1), with a PHA content of 11% (on a COD basis). The enriched microbial biomass was then transferred into a batch reactor where the bacterial polymer content was increased through a new feeding. In the final batch stage, maximum storage rate and maximum polymer content in the biomass were 405 mgCOD gCOD(-1) h(-1) and 44% (on a COD basis), respectively. The PHA storage from the enriched microbial biomass was about 20 times faster and the PHA content was about 4 times higher than that of the inoculated activated sludge. Observations by fluorescence microscopy showed that the majority of microorganisms in the enriched biomass could be stored. Among the numerically most representative genera in the enriched biomass, Thauera, Candidatus Meganema perideroedes, and Flavobacterium were identified
Description:Date Completed 05.12.2006
Date Revised 17.09.2019
published: Print
Citation Status MEDLINE
ISSN:0273-1223