Adsorptive removal of phosphates from aqueous solutions

Phosphates removal from aqueous solutions was investigated using three different inorganic materials: laboratory synthesized goethite, commercial alumina and commercial hydrotalcite. Equilibrium and kinetic studies were carried out to determine their sorption capacity and the rate of phosphate ions uptake. Equilibrium data were analyzed by Langmuir and Freundlich isotherms. The maximum sorption capacity at 25°C was found to be 244.58 mg g−1 for calcined hydrotalcite at 500°C, 192.9 for calcined hydrotalcite at 400°C, 144 mg g−1 for goethite, 60 mg g−1 for hydrotalcite and 34.57 mg g−1 for aluminumoxid S. Kinetic data followed a pseudo-second-order kinetic model.