Field Study of Total Phosphorus Removal from Stormwater Runoff using Adsorptive Filtration Media

摘要

Elevated loading of total phosphorus (TP) in dissolved and particulate forms has become a top priority of nationwide stormwater regulation and a pressing issue for the watershed management, especially in the nutrient sensitive water regions such as the Puget Sound and Chesapeake Bay areas. By virtue of variations in particulate size and specific gravity, common treatment practices such as sedimentation, hydrodynamic separation and inert media filtration, are able to remove a varying degree of particles and particulate P. However, these treatments are virtually ineffective with regard to the removal of dissolved P. In addition, the captured particulate P tends to partition and enter into effluent, resulting in weakened performance. In response to the advent of more stringent stormwater regulations, an adsorptive filtration media (PhosphoSorb™) was developed with deliberation of adsorption capacity, gradation, surface area, durability, toxicity, cost, environmentally friendly manufacturing process, and convenience of maintenance and disposal. Investigation of dissolved P adsorption by the media in bench-scale and pilot-scale evaluations was documented in a companion paper at EWRI2010. This paper is to further present a field study of TP removal from natural stormwater runoff using the same adsorptive filtration media. This field testing is comprised of 19 storm events spanning from 2009 to 2010. The results demonstrate greater than 65% TP removal. The adsorptive filtration media proves to be effective in removing stormwater TP.