钙-铝-铈三元复合物吸附脱除氟离子的性能及机理

    Fluoride Removal by Calcium-aluminum-cerium Ternary Composite: Adsorption Performances and Mechanism

    • 摘要: 工业产出大量氟污染废水,对环境安全与人类的健康有着严重的威胁。本文以共沉淀法合成了钙-铝-铈三元复合物(CAC),用XRD、FT-IR、N2吸附、SEM等对其进行了表征,并系统探究了CAC对氟的吸附性能及机理。结果表明,在弱酸性环境(pH值 5.0)下CAC对氟离子的吸附性能较好;CAC对氟离子的吸附属于自发、吸热的过程,且符合Langmuir模型,通过模型拟合计算出对氟离子的最大吸附容量为56.28 mg/g;CAC对氟离子的吸附在12 h时平衡,符合拟二级动力学模型;溶液中共存的CO32-、HCO3-等对氟离子的吸附有较大影响。CAC吸附除氟的机理主要是静电吸引作用和离子交换。

       

      Abstract: Fluoride-containing industrial wastewater poses great threat to environmental safety and human health. In this study, calcium-aluminum-cerium ternary composite (CAC) was synthesized by co-precipitation method, and characterized by XRD, FTIR, N2 adsorption, SEM, etc.. The performances and mechanisms of F- adsorption by CAC were thoroughly investigated. Experimental results showed that weakly acidic environment (pH 5.0) was favorable for F- removal by CAC adsorption. F- adsorption by CAC was a spontaneous and endothermic process, which could be well described by the Langmuir model. The maximum adsorption capacity was calculated to be 56.28 mg/g, while the adsorption equilibrium reached at about 12 h. The pseudo-second-order kinetic model fitted the adsorption kinetic well. F- adsorption was remarkably affected by the co-existing CO32- and HCO3-, while Cl-, Br-, SO42- influenced F- adsorption little. Electrostatic attraction and ion exchange were considered to be the main adsorption mechanisms.

       

    /

    返回文章
    返回