Low concentration of phosphorus removal in waters with CaO_2

Aiming at the advanced purification of low concentration of phosphorus in natural water,the adsorption of phosphate by CaO2 was studied using the models of adsorption kinetics and adsorption isotherm,and the influence of different operating parameters on the phosphorus removal was investigated. The results showed that:( 1) The experimental data for the process of phosphate uptake onto CaO2 fit the Langmuir isotherm mode,and the maximum adsorption capacity was 381. 7 mg / g( 25℃).( 2) Thermodynamic parameters in the process of phosphorus removal are ΔG0 0 and ΔH0 0,while the process was a spontaneous exothermic one.( 3) The adsorption performance of CaO2 was evaluated by the pseudo-second-order reaction rate equation,when the adsorption rate increased with the increasing concentration of phosphate in the solution,and the adsorptive reaction reached equilibrium in 4 minutes.( 4) The optimized effect of phosphorus removal was obtained at p H = 8.( 5) Among the high concentrations of coexisting anions,the CO2-3expressed the greatest influence on phosphorus removal of CaO2 and could make the adsorption capacity reduce 14. 7% under the concentration of 10 times.