USING IRON–INFUSED MEDIA AND STORMFILTER™ TECHNOLOGY FOR THE REMOVAL OF DISSOLVED PHOSPHORUS FROM STORMWATER DISCHARGES

Iron-infused resin was evaluated for the removal of dissolved phosphorus from stormwater through isotherm sorption studies and using both a horizontal flow column and a StormFilter™ cartridge. Sorption studies produced a maximum sorption of dissolved phosphorus at 840 mg-P/l over 24 hours. Horizontal flow column tests had an average mass removal of 21.7% dissolved phosphorus, 26.7% total phosphorus and 74.6% total suspended solids (n = 11). Dissolved phosphorus removal stabilized at approximately 20% mass removal during the testing. Cartridge testing had an average mass removal of 38.6% dissolved phosphorus, 44.9% total phosphorus and 78.6% total suspended solids (n = 6). Increased removals between test cycles over one day were 9.8% and 19.2% with four days between cycles. This suggests increased oxidation of the iron to provide additional sites for phosphorus sorption.