Phosphate Uptake in Co-precipitation Systems Targeting Low Phosphate Concentrations
Abstract:Achieving very low residual phosphorus (P) concentrations in wastewater treatment plant effluents is becoming increasingly important. The use of chemical P removal with iron(III) salts to achieve these low concentrations has been shown to be characterized by rapid equilibrium precipitation of hydrous ferric oxides occurring simultaneously with co-precipitation of phosphate, followed by a slower kinetic removal as a result of chemisorption. The effects of pH, dosing, mixing and aging conditions, as well as water chemistry, dictates the extent to which these mechanisms will perform. Model development has increased the ability to predict residual phosphate (PO4 3−) concentrations; however, existing models do not include all of the mechanisms responsible for P removal to ultra low levels. Currently, there is a lack of information on P removal mechanisms in transient processes and dynamics typical of wastewater treatment. In particular, there is limited information that describes the effect of solids aging and the rates of adsorption and desorption of soluble P. This paper presents preliminary data of a multiphase project aimed at resolving issues related to PO4 3−uptake in co-precipitation systems when extremely low PO4 3−concentrations (i.e. <50ug/L) are targeted. This involved identifying the impact of solids residence time (SRT) on PO4 3− uptake from water and a characterization of the desorption of P from solids generated over a range of SRTs that are commonly employed in wastewater treatment. The work will be used to enhance models of PO4 3− uptake in co-precipitation systems operating under steady-state and transient conditions, which can ultimately lead to more accurately prediction of optimum chemical dosage for P removal to ultra low level.
Document Type: Research Article
Publication date: 2011-01-01
More about this publication?
- Proceedings of the Water Environment Federation is an archive of papers published in the proceedings of the annual Water Environment Federation® Technical Exhibition and Conference (WEFTEC® ) and specialty conferences held since the year 2000. These proceedings are not peer reviewed. A subscription to the Proceedings of the Water Environment Federation includes access to most papers presented at the annual WEF Technical Exhibition and Conference (WEFTEC) and other conferences held since 2000. Subscription access begins 12 months after the event and is valid for 12 months from month of purchase. A subscription to the Proceedings of the Water Environment Federation is included in Water Environment Federation (WEF) membership.
WEF Members: Sign in (right panel) with your IngentaConnect user name and password to receive complimentary access. Access begins 12 months after the conference or event
- Subscribe to this Title
- Membership Information
- About WEF Proceedings
- WEFTEC Conference Information
- Learn about the many other WEF member benefits and join today
- Ingenta Connect is not responsible for the content or availability of external websites