Phosphorus removal by blast furnace slag and cement clinker – flow cell studies for estimation of sorptive capacity for use with constructed treatment wetlands

Blast furnace slag and cement clinker were explored in long-term flow cell experiments for estimation of their phosphorus (P) removal efficiencies. A local gravel, typically used in constructed treatment wetlands, was used as a control medium. The experiments examined the removal of phosphorus from a solution initially containing 4 mg P/L. The slag and clinker were nearly 100% efficient due to very high sorptive capacities. The control gravel medium removed 50% of the influent phosphorus. Results from this study indicate that the use of blast furnace slag in constructed wetlands or filter beds is a promising solution for P removal via sorption mechanisms.