Biological Phosphorus Removal Potential Test

Biological phosphorus removal (BPR) techniques offer a number of advantages over chemical addition, including enhanced treatment, reduced energy consumption, and reduced sludge production. A rapid, low-cost method for determining the feasibility of biological phosphorus removal should allow these techniques to be more widely used. A simple test is proposed to determine the amount of phosphorus that can be removed from a particular wastewater using a BPR process. The test involves measuring phosphorus release during a 2-hour anaerobic stage in a batch reactor containing phosphorus-removing organisms (PAOs) and estimating the effluent phosphorus concentration using a biochemical relationship. The BPR potential test developed in this study was used to evaluate BPR feasibility of five wastewaters. Comparing the test result with the effluent phosphorus concentration from a sequencing batch reactor validated the BPR potential test. An effluent phosphorus concentration predicted by the BPR potential test, compared favorably to the average effluent concentration obtained from the SBR. The initial sludge concentration affected the phosphorus release rate to a greater extent at the beginning of the anaerobic stage but to a lesser extent after 2 hours. It is recommended that the BPR potential test be conducted at a location where a PAO-containing sludge is available (either from an operating, full-scale BPR plant or from a lab-scale reactor) and that the wastewater samples be stored at 4°C for less than 24 hours. * Department of Civil and Environmental Engineering, University of Wisconsin-Madison, Madison, WI. ** DNR Bureau of Watershed Management, Madison, WI.