Study on Phosphate Removal from Aqueous Solution Using Fe-Mn-Zn Trimetal Oxide Modified Fly Ash

摘要

In this work the adsorption of phosphate using the Fe-Mn-Zn trimetal oxide modified fly ash was studied. The experimental results showed that the absorbent could effectively remove phosphate in the pH range 4 to 9 and the maximum phosphate adsorption was at pH 8.0. Kinetic study showed that the phosphate adsorption was well described by pseudo-second-order model. The removal efficiency of phosphate increased with the increase of adsorbent dosage and the decrease of the initial concentration. The adsorption of phosphate could be well described by Langmuir isotherm, the Langmuir constant Q_0 was 19.22mg/g. Comparative phosphate adsorption study of the untreated fly ash and the modified fly ash showed that modification with Fe-Mn-Zn trimetal oxide could significantly enhance the phosphate adsorption of the fly ash. The Fe-Mn-Zn trimetal oxide modified fly ash was a potential adsorbent for the removal of phosphate from aqueous systems.