铝掺杂赤铁矿的磷酸盐吸附性能与机理研究OA

To investigate the influence mechanism of aluminum doping on the phosphate adsorption of hematite(Hem),batch adsorption experiments,X-ray diffraction,and attenuated total reflection Fourier transform infrared spectroscopy were employed to analyze the adsorption characteristics and surface chelated form of phosphate.The results showed that aluminum doping promoted the preferential growth of the(110)crystal facet of Hem and increased the density of surface hydroxyl groups.The kinetic adsorption and isothermal adsorption parameters were well described by pseudo-first-order/pseudo-second-order kinetic models and Langmuir model,respectively.The initial adsorption rate,saturated adsorption capacity,and adsorption affinity constant of Hem with an aluminum doping mole fraction of 0.10 were measured to be 1.7,1.5,and 1.7 times those of pure Hem,respectively.The phosphate mainly existed on the Hem surface in three configurations:hydrogen-bonded outer-sphere complexes,monoprotonated bidentate binuclear,and monoprotonated monodentate mononuclear inner-sphere complexes.Aluminum doping promoted the formation of monodentate mononuclear complexes while enhancing the adsorption capacity.This study could provide new insights to figure out the fate of phosphorus in aluminum iron binary mineral environments.