Related Experiment Video
Updated: May 24, 2026

Mesocosm-Scale Constructed Wetland Design for Wastewater Treatment
Published on: May 2, 2025
Critical modeling parameters identified for 3D CFD modeling of rectangular final settling tanks for New York City
K Ramalingam1, S Xanthos, M Gong
1Department of Civil Engineering, The City College of NY, New York, NY 10031, USA. kramalingam@ccny.cuny.edu
Abstract:
New York City Environmental Protection is in the process of incorporating biological nitrogen removal (BNR) in its wastewater treatment plants (WWTPs) which entails operating the aeration tanks with higher levels of mixed liquor suspended solids (MLSS) than a conventional activated sludge process. The objective of this paper is to discuss two of the important parameters introduced in the 3D CFD model that has been developed by the City College of New York (CCNY) group: (a) the development of the 'discrete particle' measurement technique to carry out the fractionation of the solids in the final settling tank (FST) which has critical implications in the prediction of the effluent quality; and (b) the modification of the floc aggregation (K(A)) and floc break-up (K(B)) coefficients that are found in Parker's flocculation equation (Parker et al. 1970, 1971) used in the CFD model. The dependence of these parameters on the predictions of the CFD model will be illustrated with simulation results on one of the FSTs at the 26th Ward WWTP in Brooklyn, NY.
Related Concept Videos
Typical Model Studies
Design Example: Creating a Hydraulic Model of a Dam Spillway
Modeling and Similitude
Conservation of Mass in Moving, Nondeforming Control Volume
In the context of a detention basin, the conservation of mass states that the total mass of water entering the basin must equal the mass leaving the basin plus any accumulation of...
Design Example: Analyzing Capacity Contours for Flood Risk Assessment
Laminar Flow
