Greening the gray infrastructure: Green adsorbent media for catch basin inserts to remove stormwater pollutants

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Department of Biological Sciences


Stormwater pollution is a major cause of water quality impairment. Much of the existing gray stormwater infrastructures provide little or no treatment, especially for dissolved pollutants. Due to the capital cost of installing new infrastructure, retrofitting the existing gray infrastructures is a promising alternative to reduce stormwater pollution. In this study, aluminum-based drinking water treatment residuals (WTR), a byproduct from drinking water treatment, was combined with other common materials (sand and carbon material) to formulate an adsorbent media for use in catch basin inserts to remove total petroleum hydrocarbons (TPH), and dissolved Cu, Pb, and Zn from stormwater runoff. Hydraulic and treatment performance of the adsorbent media were optimized in laboratory column experiments. A dual-layer media, WTR-amended sand with a mass percentage of 5% WTR relative to sand over carbon material with the depth ratio of 1:3, was selected as optimal. The breakthrough curves correlated well with the Yan model. During the field study, influent and effluent samples were collected from two catch basins from eight storm events and analyzed for turbidity, pH, TPH, and dissolved Cu, Pb, and Zn. The median removal efficiencies of dissolved Cu, dissolved Pb, dissolved Zn, and TPH during the field study were 27.4%, 36.3%, 69.3%, and 45.6%, respectively. The removal of particulate-bound pollutants was indicated by the reduction of turbidity with the median removal efficiencies of 81.2%. A slight increase in pH was observed. There was no water ponding during the study. Our results show that this low-tech, low-cost adsorbent media is effective in reducing metal and organic pollutants in stormwater.

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© 2020 Elsevier B.V. Publisher’s version of record:

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Environmental Technology and Innovation