Abstract: Red mud from sintering process was activated by hydrogen peroxide with different concentrations. Static adsorption method was adopted to study the adsorptive performances of the different activated red muds to phosphate.Influences of various factors,such as treated temperature,reaction time,and pH,on the removal of phosphate were investigate respectively．Thermal analysis techniques,XRD,and SEM were used to characterize red muds that activated before and after.Results showed that the modified red mud had prominent effect on phosphate removal comparing with those unmodified.At 700 ℃,the saturated adsorbing capacity of the red mud treated with hydrogen peroxide（mass fraction of 15%） could reach 252.40 mg/g.Experiment showed that the adsorption behavior of phosphate by the treated red mud accorded with Langmuir isotherm model,and it belonged to monomolecular adsorption.The study showed that activated red mud can be used as high efficient adsorbent to remove phosphate from the wastewater and has a good application prospect.

Key words: red mud sorbent, phosphate removal, adsorption