Study of Sulfate Adsorption onto Magnetic Nano-zirconium Hydroxide

Magnetic nano-zirconium hydroxide,prepared by sol-gel method using nano-Fe3O4,ZrOCl2 and NH4OH,was used as an adsorbent for sulfate adsorption experiment investigating the influencing factors of pH,dosage of the adsorbent and temperature.The experimental results showed the optimal range of pH,the main factor affected the adsorption,was between 1 and 2,and the adsorption isotherm fit well to Langmuir monolayer model.Analysis on thermodynamic parameters ΔG0,ΔH0 and ΔS0 indicated that the adsorption process featured endothermic and spontaneous with an increase of entropy,and the pseudo second-order model could better fit to the dynamic process during adsorption.As to the experiment on desorption of sulfate and regeneration of the saturated adsorbent using NaOH solution,the result showed just a slight decrease of adsorption capacity following a number of times of regeneration,which indicated magnetic nano-zirconium hydroxide as an adsorbent was of perfect characteristics.