title: Study of phosphate removal from aqueous solution by zinc oxide.
abstract: Zinc oxide (ZnO) was synthesized and used to investigate the mechanism of phosphate removal from aqueous solution. ZnO particles were characterized by X-ray diffraction, scanning electron microscope and Fourier transform infrared spectroscopy before and after adsorption. Batch experiments were carried out to investigate the kinetics, isotherms, effects of initial pH and co-existing anions. The adsorption process was rapid and equilibrium was almost reached within 150 min. The adsorption kinetics were described well by a pseudo-second-order equation, and the maximum phosphate adsorption capacity was 163.4 mg/g at 298 K and pH ∼6.2±0.1. Thermodynamic analysis indicated the phosphate adsorption onto ZnO was endothermic and spontaneous. The point of zero charge of ZnO was around 8.4 according to the pH-drift method. Phosphate adsorption capacity reduced with the increasing initial solution pH values. The ligand exchange and Lewis acid-base interaction dominated the adsorption process in the lower and the higher pH range, respectively. Nitrate, sulfate and chloride ions had a negligible effect on phosphate removal, while carbonate displayed significant inhibition behavior.
authors: School of Environment, Northeast Normal University, Changchun 130117, China E-mail: yangw104@gmail.com.
authors: Zhen
authors: Z
authors: Luo
authors: School of Environment, Northeast Normal University, Changchun 130117, China E-mail: yangw104@gmail.com.
authors: Suiyi
authors: S
authors: Zhu
authors: School of Environment, Northeast Normal University, Changchun 130117, China E-mail: yangw104@gmail.com.
authors: Zhongmou
authors: Z
authors: Liu
authors: School of Environment, Northeast Normal University, Changchun 130117, China E-mail: yangw104@gmail.com.
authors: Jiancong
authors: J
authors: Liu
authors: School of Environment, Northeast Normal University, Changchun 130117, China E-mail: yangw104@gmail.com.
authors: Mingxin
authors: M
authors: Huo
authors: School of Environment, Northeast Normal University, Changchun 130117, China E-mail: yangw104@gmail.com.
authors: Wu
authors: W
authors: Yang
mesh_terms: D000327:Adsorption; D006863:Hydrogen-Ion Concentration; D010710:Phosphates / Q000737:chemistry / Q000302:isolation & purification*; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D018508:Water Purification; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: D010710:Phosphates; D014874:Water Pollutants, Chemical; D015034:Zinc Oxide