Synthesis And Characterization Of Hematite （α-Fe₂O₃） Iron Oxide-coated Silica And Its Adsorption,Desorption Behavior With Copper Ions In Aqueous Solution

This research study aims to improve the surface quality of synthetic Hematite（→-Fe₂O₃）iron oxide coating sand.Our main focuses to coat the sand surface with iron oxide,which is hematite（→-Fe₂O₃）composition,more stable,environmental friendly,evaluate the amount of iron oxide content on each sand surface and its adsorption,desorption behaved with copper ions in aqueous solution.For this purpose,we prepared three different control pH（1,5,and 10）solutions of FeCl3 for the achievement of the above results.X-ray diffraction,Scanning electron microscopy（SEM）,EDX,and FT-IR analysis were performed for characterization of the surface morphological properties of the coated layer,and copper ions adsorption on the coated sand surface.Batch experiments were conducted for copper ions adsorption at specific parameters such as the influence of time,dosage,pH,and initial copper concentration effect.The adsorption isotherm and kinetic models were used for fitting the experimental data at different temperatures（15,25,and 35℃）.Different desorption medium,HCl,HNO3,CH3OOH,NaOH,distilled,tap water,and recycle of hematite iron oxide coated sand,was also performed in this study.It was investigated that high intensity and pure hematite（→-Fe₂O₃）crystal peaks and iron amount were found on sand coated at pH 1,the copper ions removal efficiency is also found more effective（85-94%）than those of sand coated at high pH（5,and 10）.The maximum amount of Cu2+absorbed by hematite（→-Fe₂O₃）iron oxide coated sand was found more effective,qm=3.93 mg/g than some other rich iron oxide adsorbents product.The Langmuir isotherm model and pseudo-second-order of sorption kinetic are found better correlated than the Freundlich model isotherm and pseudo-first-order of sorption kinetic of equations.The column removal efficiency was found 95%at 1 L/hr.desorption,recycling,and backwashing of the column are also performed very well,H2SO4 and HCl solution were found an effective medium for desorption,the maximum uptake of copper ion real environment was recorded 1.12 mg/g However it was observed that the removal efficiency in a real environment is lower than laboratory test it’s because the presence of other impurities and ions in real environment samples wastewater which fill-up the pores sites of hematite iron oxide coated sand.