Reduce the Degradation of Polyhydroxyalkanoates: Feeding in the Oxygen-limiting Section Increases the Accumulation of PHAs

Abstract To solve the problem that the content of polyhydroxyalkanoates (PHAs) in the aerobic section of the traditional anaerobic-aerobic process continues to decrease, two different feeding modes in the oxygen-limiting section were explored under the anaerobic-oxygen limiting process(for reducing the energy consumption of aeration). Based on 16SrRNA sequence analyses, the results show that the abundance of Hydrogenovora(9.57%), Zoogloea(6.73%), Thaurea(1.49%) and other bacterial genera in the microbial community had increased after enrichment. PHAs were synthesized in the oxygen-limiting stage of both one-time feeding and batch feeding mode. The maximum content of PHA reached 52.17% when C/N increased to 150 in the one-time feeding mode, and that reached 42.04% in batch feeding mode when C/N was 100. The one-time feeding mode shows a more significant accumulation potential of PHAs than the batch feeding mode. The content of PHAs shows an increasing trend with the increase of C/N ratio, and a high C/N ratio may lead to sludge bulking and other problems, making the sludge system unsteady.