Pine Creek WWTP
City of Calgary, Alberta (Canada)
The 100 ML/d Pine Creek WWTP is a state-of-the-art BNR facility that serves the City of
Calgary, Alberta. A delay in the construction of the primary sludge fermenters allowed a
comparison of the performance of the BNR process with and without fermentation for
extended periods of time, and facilitated a life-cycle cost analysis in which the cost of
primary sludge fermentation was compared with alternative forms of primary sludge
thickening and meeting the effluent total P limit by chemical addition. Data from the first 20
months of plant operation indicated that, with primary sludge fermentation, the plant is
capable of reliably meeting its stringent effluent total P target of <0.3 mg/L. Without
fermentation, the plant required the in-plant addition for approximately 50 mg/L of alum to
meet this same effluent quality standard. The life-cycle cost comparison between primary
sludge fermentation and enhanced biological phosphorus removal (EBPR), and two
alternative forms of primary sludge thickening and chemical P removal, indicated that
primary sludge fermentation is a cost-effective method of reliably meeting a stringent
effluent total P standard. Using a 20-year net present value (NPV) analysis, primary sludge
fermentation was found to be approximately 8 percent cheaper than mechanical primary
sludge thickening and chemical P removal, and 22 percent cheaper than gravity thickening of
primary sludge and chemical P removal.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Waste Water Treatment | Tags: Biological Nutrient Removal, Phosphorus Removal, Sludge Handling | No Comments »
City of Durham WWTF
Durham, North Carolina
The objective of this study was to utilize process modeling to predict effluent quality at design
flow for two biological nutrient removal (BNR) facilities, and determine what additional
improvements would be needed at each facility to meet limit of technology (LOT) nitrogen and
phosphorus standards. Then, optimization, pilot-testing, and bench-testing were conducted to
support this approach.
Process modeling using calibrated BioWin models determined that side stream treatment and
equalization, supplemental carbon addition, and increased nitrified recycle (NRCY) rates would
optimize nitrogen and phosphorus removal at both plants. Zone dissolved oxygen (DO) control
will also enhance denitrification and the effectiveness of the supplemental carbon. Both plants
are also considering the Ostara process to improve BPR.
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Posted: May 20th, 2011 | Filed under: 100K-500K, Stormwater, Waste Water Treatment, Water Treatment | Tags: Biological Nutrient Removal, Enhanced Denitrification, Improved Plant Performance, Optimized Nitrogen Removal, Optimized Phosphorus Removal, Plant Optimization | No Comments »
City of Greeley WPCF
Greeley, Colorado
The prime objective of the work described in this paper was to determine the correct half saturation dissolved oxygen coefficients, KDO,AOB and KDO,NOB for the ammonia oxidizing and nitrite oxidizing bacteria, respectively for accurately simulating the Greeley WPCF, using the Biowin 3™ software. These parameters are often considered to be constants, whose values are generally accepted to be the default values embedded in the Biowin 3™ software. However, they are in fact not constants, and unless care is taken in the assignment of the proper values, errors in predicted air quantities or the required DO concentrations to achieve the necessary effluent ammonia concentrations will result. Determining the specific KDO value for a given application is important because it impacts the rate of nitrification achieved for a given oxygen concentration, the SRT, the consequent size of the aeration reactors, and the energy required to maintain required DO levels. Our other experiences subsequent to the work described in this paper showed that simulation results achieved by using the half saturation coefficients determined in this paper provide a much better goodness of fit than the current Biowin 3™ default values. For future plant simulations, the same type of stress tests carried out for this work are recommended as part of the wastewater characterization and calibration exercises. However, if this is not possible, adjusting the default values in Biowin 3™ to the values presented in this paper is recommended. The work presented in this paper can only be accomplished using a properly calibrated dynamic model. A steady state modeling approach would not produce the required results and would not be suitable to confirm nitrifier growth rates with plant scale measurements. Source: WEFTEC 2009 Proceedings
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Posted: July 6th, 2010 | Filed under: 100K-500K, Waste Water Treatment | Tags: Biological Nutrient Removal, Proper Calibration for Biowin 3™ Simulation Software | No Comments »