A novel post denitrification configuration for phosphorus recovery using polyphosphate accumulating organisms

• Published in: Water research (Oxford) 2013-11, Vol.47 (17), p.6488-6495
• Main Authors: Wong, Pan Yu, Cheng, Ka Yu, Kaksonen, Anna H., Sutton, David C., Ginige, Maneesha P.
• Format: Article
• Language: English
• Subjects: aeration; anaerobic conditions; Applied sciences; Bacteria - metabolism; Biodegradation, Environmental; biofilm; Biofilms; Biological and medical sciences; Biological treatment of waters; Bioreactors - microbiology; Biotechnology; carbon; Costs and Cost Analysis; Denitrification; Denitrifying polyphosphate accumulating organisms; dissolved oxygen; Electrons; Enhanced biological phosphorus removal; Environment and pollution; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General purification processes; Industrial applications and implications. Economical aspects; Kinetics; nitrates; nitrogen; Nitrogen - isolation & purification; phosphorus; Phosphorus - isolation & purification; Phosphorus recovery; Phosphorus removal; Pollution; Polyphosphate accumulating organisms; Polyphosphates - metabolism; Post denitrification; Sewage - microbiology; Solubility; streams; wastewater; Wastewater treatment; Wastewaters; Water treatment and pollution
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2013.08.023

Enhanced biological phosphorus removal (EBPR) has been widely used to remove phosphorus (P) from wastewater. In this study we report a novel modification to the EBPR approach, namely enhanced biological phosphorus removal and recovery (EBPR-r) that facilitates biological recovery of P from wastewater using a post denitrification configuration. The novel approach consists of two major steps. In the first step, a biofilm of phosphorus accumulating organisms (PAOs) is exposed to a wastewater stream in the absence of active aeration, during which P is taken up by the biofilm using nitrate and residual dissolved oxygen as electron acceptors. Thus, P and nitrogen (N) removal from wastewater is achieved. During the second step, the P enriched biofilm is exposed to a smaller recovery stream supplemented with an external carbon source to facilitate P release under anaerobic conditions. This allows P to be recovered as a concentrated liquid. The EBPR-r process was able to generate a P recovery stream four time more concentrated (28 mg-P/L) than the wastewater stream (7 mg-P/L), while removing nitrate (denitrification) from the wastewater stream. Repeated exposure of the biofilm (10 P-uptake and release cycles) to a recovery stream yielded up to 100 mg-P/L. Overall, EBPR-r is the first post denitrification strategy that can also facilitate P recovery during secondary wastewater treatment. [Display omitted] •Biological recovery of P from wastewater with low P concentration (