Production of poly-β-hydroxybutyrate by activated sludge in sequencing batch reactor under aerobic conditions

Abstract

In order to improve poly-β-hydroxybutyrate (PHB) production in activated sludge, the anaerobic/aerobic alternative operating sequencing batch reactor (SBR) process was applied in this paper to accumulate PHB. Effects of nutritional conditions and carbon concentration on PHB accumulation were studied. Results indicated that PHB accumulation reached the highest level and accounted for 11.2 % under anaerobic condition for phosphate limitation and 20.84 % under aerobic condition for nitrogen and phosphate limitation of mixed liquor suspended solid (MLSS), respectively. In addition, 4 g/L was proved to be the optimum carbon concentration in both anaerobic and aerobic experiments, and the PHB accumulation reached 17.1 % (anaerobic, phosphorus limitation) and 60.4 % (aerobic, nitrogen and phosphorus limitation) of MLSS, respectively. PHB could be successfully extracted with sodium hypochlorite and chloroform method from the activated sludge. In addition, the infrared spectrum showed that the PHB sample extracted was of high purity.

Keywords

poly-β-hydroxybutyrate (PHB) / activated sludge / sequencing batch reactor (SBR)

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