Glycine functionalized activated carbon derived from navel orange peel for enhancement recovery of Gd(Ⅲ)

Glycine functionalized activated carbon adsorption material(NOPAC-GLY-X)was successfully prepared by one-step thermal decomposition using agricultural waste navel orange peel as a precursor.Through batch adsorption experiments,it is found that the adsorption performance of Gd(Ⅲ)on activated carbon can be significantly enhanced by glycine modification.The adsorption isotherms of the NOPACs conform to the Langmuir isotherm model,and the maximum adsorption capacity of the activated carbon sample NOPAC-Gly-60 is approximately 48.5 mg/g.The Gd(Ⅲ)adsorption capacity of navel orange peel activated carbon can be doubled after glycine modification,and the adsorption efficiency of gadolinium can reach99%at pH=7.The physicochemical properties of the prepared adsorbents were characterized by Brunauer-Emmett-Teller(BET),Fourier transform infrared spectroscopy(FTIR),elemental analysis(EA),and X-ray photoelectron spectroscopy(XPS).The characterization test shows that the specific surface area of the sample increases from 1121 to 1523 m^(2)/g,and the ratio of(N+O)/C increases from 10.8%to 30.0%by the glycine modification.After five cycles of adsorption-desorption,the adsorption capacity can still be maintained at 88%of the initial capacity.NOPAC-GLY-60 has excellent adsorption selectivity for Gd(Ⅲ).With the obvious advantages of simple synthesis steps and low cost,the activated carbon modification method adopted in this study has great application value in the field of rare earth adsorption and recovery.