Application of magnetite modified with active aluminum to adsorb phosphate in aqueous solution

• Main Authors: Lu-Huan Li, 李雨寰
• Other Authors: Chyow-San Chiou
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/82927981655183672434

碩士 === 國立宜蘭大學 === 環境工程學系碩士班 === 101 === Phosphate is one of the main contaminants responsible for the eutrophication of surface waters, and adsorption is a potential treatment method for this pollutant. A magnetic adsorbent manufactured from magnetite (Fe3O4) can be recovered easily from treated water by magnetic force, without requiring further downstream treatment. In this research, the surface of magnetite modified with active aluminum (Al2O3/ Fe3O4) was used to adsorb phosphate in an aqueous solution in a batch system. The optimum solution pH for phosphate adsorption by Al2O3/ Fe3O4 was found to be 3. The phosphate adsorption behavior of Al2O3/ Fe3O4 was in good agreement with both the Langmuir and Freundlich adsorption isotherm, and the maximum adsorption capacity (qm) and Gibbs free energy of phosphatewas 36.56 mg-P g−1 and−4.38 kJ mol−1, respectively. A pseudo-second-order model could best describe the adsorption kinetics, and the derived activation energy was 17.89 kJ mol−1. The optimum condition to desorb phosphate from Al2O3/ Fe3O4 is provided by a solution with 0.5mol L−1 NaOH.