ASCE has honored the writing team of David W. Spelman, Ph.D., EI, A.M.ASCE, and John J. Sansalone, Ph.D., P.E., M.ASCE, with the 2019 Rudolph Hering Medal for the paper “Is the Treatment Response of Manufactured BMPs to Urban Drainage PM Loads Portable?” published in the April 2018 issue of the Journal of Environmental Engineering.
Hydrodynamic separators (HS) and basins/tanks such as rectangular clarifiers (RC), as unit operations (UOs) for particulate matter (PM) separation, are common smaller-footprint best management practices (BMPs). In the selected paper, the authors examine specific parameters with potential to alter UO behavior: (1) hydrograph unsteadiness; (2) PM particle-size distribution (PSD); (3) PM specific gravity (ρsg); and (4) water temperature. In this study, UO behavior as PM separation efficiency (ßPM) is normalized for each parameter to examine whether UO results can be ported across a series of urban environs. To generate normalized ßPM results, computation fluid dynamics (CFD) models of the HS and RC are applied for seven flow rates, three levels of ρsg, and three temperatures over a heterodisperse PSD from 1 to 2,000 μm. CFD models were validated within 10% of physical model results for measured events. Additionally, these parameters were analyzed with normalized ßPM results to model three hydrographs loading the HS and RC.
Results indicate that the greatest impact on UO behavior is influent PSD, whereas ρsg and hydrograph characteristics have significant but less pronounced impacts. Temperature has a minor impact. Results demonstrate that the normalized ßPM approach for a specific UO accounts for the variability of the common parameters examined, and thus UO behavior can be portable across geographic locations. Results further suggest the potential of a more unified physical model testing protocol for UO certification and the deployment of validated CFD models to support physical testing.
The Rudolph Hering Medal recognizes outstanding papers that contribute to the advancement of the environmental branch of the engineering profession.