Assessment of Copper Removal From Highway Stormwater Runoff Using Apatite II? and Compost: Laboratory and Field Testing.

摘要

Storm-water runoff introduces heavy metals to surface waters that are harmful to aquatic organisms, including endangered salmon. This work evaluates Apatite II?, a biogenic fish bone based adsorbent, for removing metal from stormwater. The metals removal by Apatite II? is compared to that of compost. Compost is commonly used in stormwater BMPs. At equilibrium and in column tests, both compost and Apatite II? removed copper and zinc to trace levels.. The introduction of natural organic material (NOM) rendered both adsorbents less effective in all tests. There was indication that dissolved copper in the effluent was fully complexed with NOM, effectively removing the bioavailable, free copper (Cu+2). In field testing Apatite II? removed, copper for three of seven storms with efficiencies ranging from 16.1% to 59.8%. Compost removed copper in three of five storms sampled, with efficiencies ranging from 24.7% to 45.4%. Ion leaching was observed for both media types. At the field level, steady state phosphate release of approximately 1.5 mg/L was observed for Apatite II. For compost, field levels of leaching trend of nitrate and phosphate had not yet stabilized after approximately 7,300 gallons of flow through the filter. Due to the superior performance of compost, the steady state leaching of phosphate from Apatite II?, and the potential for Apatite II? to release copper back into solution, compost is viewed as the more promising adsorbent for stormwater applications.