Biological Phosphorus Removal Design

The Great Lakes Protection Fund awarded a grant for the Ashland Biological Phosphorus Removal Study to the Wisconsin Department of Natural Resources (WDNR). The project is intended to promote the use of Biological Phosphorus Removal (BPR) as an alternative to chemical precipitation. BPR methods provide a number of advantages over chemical addition including enhanced treatment, reduced chemical usage, reduced energy consumption, reduced sludge production, and improved sludge settling and dewatering characteristics.

The Ashland Biological Phosphorus Removal Study is a cooperative effort between the WDNR, the City of Ashland, WI and the University of Wisconsin - Madison. The project promotes the use of computer-aided design models as an alternative to expensive pilot-testing of BPR designs. The use of such models is currently limited by a lack of information on the design parameters needed as inputs to the models. The development of simplified wastewater characterization procedures which can provide the needed physical, chemical, and biokinetic parameters is a key to increased use of models in design.

The project resulted in the publication of two WDNR Research Reports. The first report: Wastewater Characterization for Evaluation of Biological Phosphorus Removal, Research Report 174, provides simplified methods for determining the design parameters needed to run process design computer programs such as the ENBIR program, developed by Professor Jae Kwang Park and in the public domain, and commercially available programs such as BIOSIM. These models can then be used to design BPR treatment systems. Both the Wastewater Characterization for Evaluation of Biological Phosphorus Removal Report and ENBIR program can be downloaded here.

Research Report 179 presents a new BPR Potential Test that allows you to predict the amount of phosphorus that can be removed by a BPR system. The test provides a rapid, low-cost method for determining how amenable a particular wastewater is for biological phosphorus removal. It is envisioned that this test would be the first step in the evaluation of BPR. If the results are favorable, the required wastewater parameters can be determined using the procedures provided in the Wastewater Characterization report, and a computer model used to design the BPR system.

A paper presented at WEFTEC 96 in Orlando (Garman, K.R., M.J. Tetreault, P. L. Dold, D. S. Parker and H.R. Finley, Evaluation of Critical Activate Sludge Parameters for Dynamic Process Models) suggested that further simplification of the design process was possible by assuming that kinematic and stoichiometric parameters remain relatively constant. Therefore it may be sufficient to determine the COD and TKN fractions and the specific nitrification rate, and use default values for the other process design parameters.

Additional information provided here includes a report on use of an Intermittent Aeration mode of operation at Ashland and two PowerPoint presentations on BPR design by Professor Park.

This information is provided by the Department of Natural Resources and University of Wisconsin-Madison as a public service and neither the Department nor the University assumes responsibility for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use of any methods, products, instructions or ideas contained in this material.

For further information on this project contact: Gerry Novotny, WDNR, (608) 267-7625.

Last Revised: Monday July 24 2006