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.
File in questo prodotto:
Non ci sono file associati a questo prodotto.