Effect of Temperature on the Polyhydroxyalkanoate Synthesis Performance of the Activated Sludge

Polyhydroxyalkanoate (PHA) is thermoplastics synthesized by bacteria under stress growth condition. In this experiment, effect of temperature on PHA accumulation is investigated. PHA is produced by activated sludge with acetate as a carbon source under imbalanced nutrition condition. Two sequencing batch reactors are operated in anaerobic-aerobic cycle with P limitation and N limitation separately, changing temperature step by step at 16°C, 19°C, 23°C, 26°C and 29°C. The experiments´ results showed that in P limitation phase PHA was synthesized greater at 19°C and in N limitation phase PHA was synthesized greater at 16°C, the amount of PHA yield under temperatures mentioned above were obtained at 11.76% of cell dry weight (CDW, w/w) and 28.49% of CDW (w/w) respectively, equal to 0.31 mgPHA/mgCOD consumed and 0.75 mgPHA/mgCOD consumed.