Fe_3O_4/活性炭磁性材料的合成及其对茜素红染料的吸附性能

Synthesis of Fe_3O_4/activated carbon magnetic material and its adsorption property of alizarin red dye

以氢氧化钠水热法预处理的活性炭(AC)为原料,采用溶剂热法合成Fe_3O_4/AC磁性材料,通过振动样品磁强计、X射线衍射、红外光谱、比表面积及孔径分析等分析方法对所合成的磁性材料进行表征,试验着重研究了其作为吸附剂对茜素红(AR)的吸附性能。结果表明,温度、pH值和Fe_3O_4/AC用量对吸附效果有一定影响。在最佳吸附条件下,Fe_3O_4/AC对茜素红的去除率可达96%以上。等温吸附数据同时符合Langmuir和Freundlich模型,最大吸附量为344 mg·g-1. Fe_3O_4/AC对茜素红具有很好吸附性能的原因是由于Fe_3O_4/AC和茜素红之间存在较强的氢键和π-π相互作用。吸附过程是自发进行的吸热过程,符合假二级动力学模型,速率控制步骤为颗粒内扩散,再生6次后的Fe_3O_4/AC复合材料对茜素红的去除率达到65%.

Fe3O4/activated carbon(AC)magnetic materials were synthesized via solvothermal method by using sodium hydroxide hydro-thermal treated AC as raw material.The obtained composite was characterized by vibrating sample magnetometer,X-ray diffraction,Fourier transform infrared spectroscopy and Brunauer-Emmett-Teller surface area methods.The adsorption property of alizarin red(AR)by Fe3O4/AC was emphatically investigated.The results showed that the removal efficiency of AR was affected by temperature,pH and Fe3O4/AC dosage.Under the optimum adsorption conditions,the removal efficiency of AR can be achieved above 96%.The equilibrium adsorption data fitted well to Langmuir and Freundlich models,and the maximum adsorption capacity was found to be 344 mg·g^-1.The remarkable adsorption capacity of AR onto Fe3O4/AC composite can be attributed to stronger hydrogen bonds andπ-πinteractions between AR and Fe3O4/AC.The adsorption of AR is a spontaneous and endothermic process,and fitted well to the second order kinetic model which was controlled by intraparticle diffusion procedure.The removal efficiency of AR by Fe3O4/AC after being regenerated six times can reach 65%.