Adsorption Kinetics, Isotherms, and Thermodynamics of Cr(III), Pb(II), and Cu(II) on Porous Hydroxyapatite Nanoparticles

Porous hydroxyapatite (HAP) nanoparticles with the specific surface area of 76.1 m2 g-1 were facilely prepared using calcium nitrate and phosphoric acid as the starting materials and ammonia aqueous solution as the pH regulator by a hybrid precipitation and hydrothermal method at lower reaction temperatures of 35 and 110 °C. The adsorption of Cr(III), Pb(II), and Cu(II) ions on HAP nanoparticles was well simulated by the pseudo-second-order...