In this research the production of polyhydroxyalkanoates (PHA) by activated sludge enriched in a sequencing batch reactor (SBR) at high organic load, has been investigated. The SBR was operated at four different organic load rates (OLR), in the range 8.5 - 40.8 gCOD/L/day, and hydraulic retention times (HRT) in the range 1 - 0.21 day, both being simultaneously varied by changing the cycle length from 2 h to 0.42 h. Both parameters affected the establishment of the feast and famine conditions needed for the selection of PHA-producing microorganisms. The highest observed values of polymer production rates and yields (∼ 400 mgCOD/gCOD/h and 0.53 COD/COD, respectively) were obtained at the lowest OLR investigated (8.5 gCOD/L/day), with a corresponding HRT of 1 day. Microbial community analysis, based on denaturing gradient gel electrophoresis (DGGE), revealed that hydraulic and organic loads also played a main role on the microbial speciation within the SBR.

Effect of Hydraulic and organic loads in sequencing batch reactor on microbial ecology of activated sludge and storage of polyhydroxyalkanoates

LAMPIS, Silvia;VALLINI, Giovanni;
2010

Abstract

In this research the production of polyhydroxyalkanoates (PHA) by activated sludge enriched in a sequencing batch reactor (SBR) at high organic load, has been investigated. The SBR was operated at four different organic load rates (OLR), in the range 8.5 - 40.8 gCOD/L/day, and hydraulic retention times (HRT) in the range 1 - 0.21 day, both being simultaneously varied by changing the cycle length from 2 h to 0.42 h. Both parameters affected the establishment of the feast and famine conditions needed for the selection of PHA-producing microorganisms. The highest observed values of polymer production rates and yields (∼ 400 mgCOD/gCOD/h and 0.53 COD/COD, respectively) were obtained at the lowest OLR investigated (8.5 gCOD/L/day), with a corresponding HRT of 1 day. Microbial community analysis, based on denaturing gradient gel electrophoresis (DGGE), revealed that hydraulic and organic loads also played a main role on the microbial speciation within the SBR.
SEQUENCING BATCH REACTOR; POLYHYDROXYALKANOATES; MICROBIAL SPECIATION; DGGE; PHA-PRODUCING BACTERIA
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11562/391667
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 21
  • ???jsp.display-item.citation.isi??? 16
social impact