Secondary Impacts of Supplemental Carbon Addition to BNR/ENR Treatment Processes

Abstract

Nitrogen removal to increasingly strict discharge standards requires, in many cases, the use of supplemental carbon (methanol, glycerol, acetate, sugar water, etc). The supplemental carbon provides the driving force for further biological denitrification and is typically applied as a polishing treatment such as to a post anoxic zone or a tertiary denitrification filter. The practical use of supplemental carbons has attracted substantial attention from both process optimization and cost minimization perspectives. This paper presents the operational experiences gained with the secondary and indirect impacts of supplemental carbon addition to BNR/ENR treatment facilities at the Parkway WWTP, located in Laurel, Maryland, and at the Henrico County WRF, located in Richmond, Virginia. The focus of the paper deals with the sometimes unexpected beneficial secondary effects of supplemental carbon addition to post anoxic zones in the BNR/ENR treatment processes.

Computer Simulation in Predicting Biochemical Processes and Energy Balance at WWTPs

“…Phillips et al [11] used a dynamic model to optimize the mixed liquor recycle rate and studied factors that affected nitrogen removal, including the influent wastewater readily biodegradable COD/N ratio and acetate addition. The strategies and calculations of the optimum COD/N ratios were investigated by FilaliMeknassi et al [12] (in sequencing batch reactor (SBR)) and Latimer et al [13] (in continuous flow reactor). In this study not only biological part of WWTP was simulated but more complex newly developed model of whole plant Mantis2 (which is extension of well known ASM) was calibrated/validated, behaviors of real date NH 4 -N and NO 3 -N and PO 4 -P in the anoxic/aerobic tank of full-scale MUCT bioreactor, as a sample results presented Figure 2c, were matched accurately by the model predictions in the GPS-x simulator.…”

Modeling External Carbon Addition in Biological Nutrient Removal Processes with an Extension of the International Water Association Activated Sludge Model

“…Phillips et al (2009) used a dynamic model to optimize the mixed liquor recycle rate and studied factors that affected nitrogen removal, including the influent wastewater readily biodegradable COD/N and acetate addition. Strategies for dosing external carbon sources and calculations of the optimum COD/N were investigated by Latimer et al (2009) (sugar addition to a continuous flow reactor) and Filali-Meknassi et al (2005) (acetate addition to a sequencing batch reactor). Using a simplified version of the International Water Association (IWA) Activated Sludge Model No.…”