活性炭负载Fe(III)氧化物去除水中的磷酸根

Adsorptive removal of phosphate from aqueous solutions using activated carbon loaded with Fe(III) oxide

  • 摘要: 利用活性炭负载铁氧化物制备了复合吸附剂,并用于水中磷酸根的去除。采用BET,SEM及XRD等手段对复合吸附剂的物理化学特性进行了表征,用静态吸附实验方法比较研究了复合吸附剂和活性炭从水溶液中吸附磷酸根的性质。结果表明:复合吸附剂具有快的吸附速度和高的吸附容量,其吸附磷酸根的性质受溶液pH值、铁含量及阴离子浓度的影响。在pH=3.0时,复合吸附剂对磷酸根的吸附容量为98.39mg/g,而活性炭为78.90mg/g。相比之下,Freundlich模型比Langmuir模型能更好地描述复合吸附剂和活性炭对磷酸根的吸附过程;而Lagergren二级方程却能很好地描述复合吸附剂对磷酸根的吸附动力学。水合氧化铁/活性炭复合吸附剂吸附磷酸根为吸热过程。

     

    Abstract: An composite adsorbent for the removal of phosphate from aqueous solutions was synthesized by loading iron oxide onto activated carbon. The adsorbent can be separated from the medium by a simple magnetic procedure owing to the magnetic properties of the iron oxides. The properties of the composite were investigated by nitrogen adsorption, scanning electron microscopy and X-ray diffraction. The adsorption of phosphate ions by the composite adsorbent and the activated carbon was compared in batch experiments. The composite adsorbent showed fast adsorption rates and high adsorption capacities and its adsorptive performance for phosphate ions was dependent on the pH value, iron content and anion concentration. The adsorption capacities of phosphate ions at pH 3.0 were 98.39mg/g for iron oxide/activated carbon composite and 78.90mg/g for activated carbon. The adsorptive isotherms for phosphate ions with activated carbon and the composite adsorbent all match the Freundlich model better than the Langmuir model. The adsorption kinetic data could be well described by the Lagergren pseudo-second-order kinetic equation. The adsorption by the composite adsorbent is endothermic for phosphate ions.

     

/

返回文章
返回