Modified Hydroxyapatite Adsorbent for Removal of Iron Dissolved in Water Wells in Sohag, Egypt

The presence of iron in water is one of the essential reasons of water pollution. In the present study, we use modified hydroxyapatite as adsorbent material to remove Fe+3 from groundwater. Different parameters such as contact time, pH, initial concentration, dosage of adsorbent, agitation speed and temperature were studied. Kinetics studies included first order (R2 = 0.939), second order (R2 = 0.963), pseudo first order (R2 = 0.977), pseudo second order (R2 = 0.997), intraparticle diffusion (R2 = 0.980), Elovich equation model (R2 = 0.993), Natarajan and Khalaf (R2 = 0.919) were carried out the obtained results revealed that the pseudo second order is best to describe the adsorption process. Adsorption capacity from Langmuir model was 0.389 mg/g. Adsorption isotherm was calculation using Langmuir, Freundlich and Temkin constants, Thermodynamic parameters (G, H and S) for adsorption process were also calculated and discussed.