Kinetics of Phosphorus Removal by Industrial by-Products.

Use of industrial by-products as phosphorus (P) sorbing materials (PSMs) is of great interest for directly removing P from wastewaters, drainage water, and surface runoff.  In order to properly design an effective structure for removing P from solution, it is first necessary to quantify the amount and rate of P sorption.  The purpose of this study was to quantify P sorption rate onto several industrial by-products using a flow-through approach.  Several PSMs were characterized for properties affecting P sorption, such as Fe, Al, and Ca concentrations and forms, pH, and electrical conductivity.  Five solution P concentrations were passed through PSMs at five different flow rates.  Outflow concentrations were monitored at various time intervals for five hours.  The cumulative P sorbed as function of P added was estimated for each flow rate and concentration; maximum P sorbed for each combination was estimated using the Langmuir model.  Phosphorus sorption rates will be discussed in the context of PSM properties.