Fig. 2. Kinetic study showing phosphorus remaining in solution after various equilibration periods with seven materials. Error bars represent ± one standard deviation. The sand-masonry was eliminated as a potential candidate material due to low P-sorption capacity, therefore it was not tested further. The organic soil had too high an in situ value in natural wetlands; therefore we did not view it as a readily available by-product. The Al#2 and sandblast grit materials were not tested due to potential toxicity concerns. The dehydrated Fe-sludge was not tested, due to it not being locally available.