Polyhydroxyalkanoates Production by Activated Sludge: Effects of Activated Sludge Organisms, PH and Initial Sludge Polyhydroxyalkanoates Content

Polyhydroxyalkanoates have attracted much interest as an alternative to traditional plastics since they are biodegradable and biocompatible. In this paper, activated sludge used for PHA production was selected and effects of pH and initial Sludge PHA Content on PHA production were studied. It was found that the aerobic activated sludge obtained the highest PHA content 52.4% under aerobic conditions with organic carbon feeding in three pulses, and the produced PHA was composed of 3HB, 3HV and 3H2MV at a ratio of around 76:23:1. Compared with pH 5 and 10, aerobic activated sludge exhibited higher and similar ability of PHA production at the pH range from 7 to 9 and when pH was not controlled. Further investigation showed that after pre-aeration aerobic activated sludge with the lowest initial sludge PHA content of 0.15% gained the highest PHA content, 55.45%.