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PHYSICAL AND SETTLING CHARACTERISTICS OF PARTICULATE IN STORM AND SANITARY WASTEWATERS (EPA/670/2-75/011)
Citation:
Dalrymple, R. J., S. L. Hodd, AND D. C. Morin. PHYSICAL AND SETTLING CHARACTERISTICS OF PARTICULATE IN STORM AND SANITARY WASTEWATERS (EPA/670/2-75/011). U.S. Environmental Protection Agency, Washington, D.C., 1975.
Description:
An investigation was conducted, as part of model studies utilizing a swirl concentrator as a primary separator, helical combined sewer overflow regulator, and related studies, to characterize the properties of solids in sanitary sewage, combined sewer overflows, and stormwater runoff. To effectuate this study, material suitable for monitoring removal efficiencies in hydraulic models of the swirl concentrator unit has been developed.
The approach taken in the simulation sewage studies was to match as closely as possible the settling characteristics of solids in three types of sewage and/or urban runoff with a welldefined, uniform artificial test material. An Amberlite anion exchange resin (IRA93), when ground and sieved to between 74 and 149 microns, was found to closely simulate the settling characteristics of domestic sewage. This material is of uniform density and appears to react according to Stokes law for spherical particles at this size range. Arizona Road Dust, between 10 and 20 microns, was found to exhibit a similar settling velocity distribution.
Importantly, as background information for the selection of synthesized solids, the settling characteristics (including size and specific gravity distribution) of a few samples of sanitary sewage, combined sewer overflow, and stormwater were determined. These values will be useful for future determinations of physical treatment process design and associated treatability.
This report on these studies recommends that either or both of these materials be used in the scalemodel efficiency trials.