【摘要】 为了获得除磷性能更优的吸附剂,以负载LaOH的膨胀石墨(expanded graphiteLaOH,EG-LaOH)为前驱体,分别于340,500和750℃下焙烧制备了镧氧化物/膨胀石墨复合吸附剂EG-LaO-340,EG-LaO-500和EG-LaO-750.通过吸附动力学和等温线实验,考察了 EG-LaO-340,EG-LaO-500和EG-LaO-750的除磷性能.结果发现,制备温度不同对吸附剂的除磷性能影响明显,其中EG-LaO-340的吸附速率和吸附容量均为最优.通过研究热力学参数和溶液初始pH对吸附容量的影响,以及扫描电镜(scanning electron microscope,SEM)和傅里叶变换红外(Fouier transform infrared,FTIR)光谱的分析进一步探讨了 EGLaO-340的除磷机理.结果表明:该吸附是一个能够自发进行的吸热过程;吸附除磷主要通过静电作用、离子交换作用和路易斯酸碱作用实现.更多还原

【Abstract】 To obtain a highly efficient phosphate removal adsorbent,lanthanum oxide/expanded graphite composite adsorbents were prepared from LaOH load-expanded graphite(EG-LaOH) at 340,500 and 750℃,namely EG-LaO-340,EG-LaO-500 and EGLaO-750,respectively.The phosphate removal performances of EG-LaO-340,EG-LaO-500 and EG-LaO-750 were investigated using adsorption kinetics and isotherm experiments.The dephosphorization of the adsorbents was found to be distinctly affected by the preparation temperature,with EG-LaO-340 having the optimal adsorption rate and adsorption capacity.The phosphorus removal mechanism of EG-LaO-340 was investigated by studying its thermodynamics and the pH dependence of adsorption.Additionally,scanning electron microscope(SEM) and Fourier transform infrared(FTIR) spectroscopy were used to characterise the adsorbents.Adsorption was found to be an endothermic and spontaneous process.Electrostatic and Lewis acid-base interactions,in addition to ion exchange,were found to be the main mechanisms of phosphate adsorption.更多还原