『Abstract
　In this study, an iron-zirconium binary oxide with a molar ratio of 4:1 was synthesized by a simple coprecipitation process for removal of phosphate from water. The effects of contact time, initial concentration of phosphate solution, temperature, pH of solution, and ionic strength on the efficiency of phosphate removal were investigated. The adsorption data fitted well to the Langmuir model with the maximum P adsorption capacity estimated of 24.9 mg P/g at pH 6.5 and 33.4 mg P/g at pH 5.5. The phosphate adsorption was pH dependent, decreasing with an increase in pH value. The presence of Cl^-1, SO4^2-, and CO3^2- had little adverse effect on phosphate removal. A desorbability of approximately 53％ was observed with 0.5M NaOH, indicating a relatively strong bonding between the adsorbed PO4^3- and the sorptive sites on the surface of the adsorbent. The phosphate uptake was mainly achieved through the replacement of surface hydroxyl groups by the phosphate species and formation of inner-sphere surface complexes at the water/oxide interface. Due to its relatively high adsorption capacity, high selectivity and low cost, this Fe-Zr binary oxide is a very promising candidate for the removal of phosphate ions from wastewater.

Keywords: Fe-Zr binary oxide; Phosphate removal; Adsorption; Mechanism』

1. Introduction
2. Materials and methods
　2.1. Materials
　2.2. Preparation of Fe-Zr binary oxide
　2.3. Batch adsorption tests
　　2.3.1. Adsorption kinetics
　　2.3.2. Effect of pH and ionic strength
　　2.3.3. Adsorption isotherm
　　2.3.4. Effect of coexisting anions
　　2.3.5. Desorption of phosphate
　　2.3.6. Characterization of adsorbent before and after phosphate adsorption
3. Results and discussion
　3.1. Adsorbent properties
　3.2. Adsorption kinetics
　3.3. Adsorption isotherm
　3.4. Effect of pH and ionic strength on phosphate uptake
　3.5. Effect of coexisting anions
　3.6. Desorption of phosphate
　3.7. Zeta potential measurement and FTIR analysis
4. Conclusions
Acknowledgment
References