Abstract:Address to phosphorus pollution in water, superfine magnesium oxide with high specific surface area was prepared by precipitation calcination method with light burning powder as raw materials. Effect of reactant concentration, reaction temperature, pyrolysis time, stirring rate, and surfactant addition on specific surface area and particle size of magnesium oxide were studied. The prepared MgO powders were characterized by XRD, SEM, BET, FTIR and particle size distribution instrument. The adsorption performance of phosphorus on MgO was studied, and the adsorption mechanism was discussed. The results show that the porous layered MgO exhibits high specific surface areas (125.52 m2/g) with average pore size of 15.17 nm under the conditions including magnesium sulfate concentration of 0.5 mol/L, reaction temperature of 80 ℃, reaction time of 120 min, stirring rate of 300 r/min, and surfactant addition of 0.5%. The prepared MgO powder is used to adsorb phosphorus waste water with the maximum adsorption capacities of 141.2 mg/g and of removal rate of PO43- of 70.6%. The adsorption of PO43- on MgO is physical-chemical combination reaction, furthermore the process is mainly chemical adsorption.