Comparing Adsorptive Media Use For The Direct Treatment Of Phosphorous-Impaired Surface Water

Removing phosphorus (P) from the environment is a growing priority for water resource stakeholders. Unlike prior research that focused on using adsorbents to treat wastewater discharges, urban stormwater, or agricultural runoff, several adsorbents were evaluated in this work for their ability to remove P directly from surface water. Isotherm models predicted that the capacity of Sorbtive Media, dried alum sludge, fly ash, and Bold and Gold solid adsorbents were 42.1, 21.3, 10.5, and 0.019 mg PO4/g adsorbent, respectively. Alum sludge and Sorbtive Media were further evaluated by packing 10% of the adsorbent with 90% sand (by volume) into 15-mm-diameter mini-columns that were fed surface water collected from the Econlockhatchee River near Orlando, FL. The average percent removal of P was 51% for the alum sludge column and 61% for the Sorbtive Media column. The adsorptive capacity of the columns was not exhausted after more than 1,300 h of continuous operation. This study shed light on the use of adsorbent materials for P removal from surface water and provides insight into the challenges of treating P from nonpoint sources