The ability of PAOs to conserve their storage-driven phosphorus uptake activities during prolonged aerobic starvation conditions. (June 2018)

• Record Type: Journal Article
• Authors: Wong, Pan Yu; Ginige, Maneesha P.; Kaksonen, Anna H.; Sutton, David C.; Cheng, Ka Yu
• Is Part Of: Journal of water process engineering. Volume 23(2018)
• Page Start: 320
• Page End: 326
• Publication Date: 2018-06
• Subjects: Denitrifying polyphosphate accumulating organism -- Phosphorus recovery -- Phosphorus removal -- Polyphosphate accumulating organisms -- Post-denitrification; Water-supply engineering -- Periodicals; Saline water conversion -- Periodicals; Seawater -- Distillation -- Periodicals; Sanitary engineering -- Periodicals; Sewage -- Purification -- Periodicals; 627
• DOI: 10.1016/j.jwpe.2018.04.014
• Languages: English
• ISSNs: 2214-7144

Abstract

Highlights: PAOs can maintain P uptake under prolonged aerobic P- and C-starvation conditions. PAOs can conserve polymers under conditions of aerobic P- and C-starvation. The EBPR-r process functions under long-term P- and C-starvation conditions. The EBPR-r process flexibly facilitates P recovery from wastewater. Abstract: A post-denitrification process, known as enhanced biological phosphorus removal and recovery (EBPR-r), was recently developed to facilitate phosphorus (P) recovery from municipal wastewater. This process utilises a biofilm containing phosphate-accumulating organisms (PAOs) to capture P from wastewater and then release the captured P into a separate smaller stream for recovery. The addition of external carbon in the EBPR-r process is expected to be a main operating cost. Hence, it is important to ensure that the added carbon, which is stored internally as poly-β-hydroxy-alkanoates (PHA) within PAOs, is predominately used for P uptake. This study explored the ability of PAOs to conserve their storage-driven P uptake activities following exposure of the biofilm to oxidising and P-deficient conditions for extended periods (up to 7 days). Even after 2 days of exposure the biofilm retained a similar ability to up take P (1.20 ± 0.09 mg-P/g total solids). Beyond 2 days of exposure, a decline in P uptake activity was noted, with only 15% activity remaining by day 7. This study provides the first evidence of the ability of PAOs to conserve their storage-driven P uptake activities. This unique behaviour of PAOs may enable flexible operational strategies, such as infrequent carbon replenishment, to be implemented (i.e. facilitate multiple P uptake phases before an anaerobic carbon replenishment). Such flexibility may reduce the capital and operational costs of the EBPR-r process, increasing the economic incentive for P recovery from wastewater.