title: Eu(III) uptake on rectorite in the presence of humic acid: a macroscopic and spectroscopic study.
abstract: This work contributed to the comprehension of humic acid (HA) effect on Eu(III) uptake to Na-rectorite by batch sorption experiments, model fitting, scanning electron microscopy, powder X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and extended X-ray absorption fine structure (EXAFS) spectroscopy. At low pH, the presence of HA enhanced Eu(III) sorption on Na-rectorite, while reduced Eu(III) sorption at high pH. The experimental data of Eu(III) sorption in the absence and presence of HA were simulated by the diffuse-layer model well with the aid of FITEQL 3.2 software. The basal spacing of rectorite became large after Eu(III) and HA sorption on Na-rectorite. Some of Eu(III) ions and HA might be intercalated into the interlayer space of Na-rectorite. EXAFS analysis showed that the R(Eu-O) (the bond distance of Eu and O in the first shell of Eu) and N values (coordination number) of Eu(III)-HA-rectorite system were smaller than those of Eu(III)-rectorite system.
authors.affiliation: Key Laboratory of Novel Thin Film Solar Cells, Institute of Plasma Physics, Chinese Academy of Sciences, P.O. Box 1126, Hefei 230031, PR China. clchen@ipp.ac.cn
authors.forename: Changlun
authors.initials: C
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Yang
authors.forename: Juan
authors.initials: J
authors.lastname: Wei
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Tan
authors.forename: Xiangke
authors.initials: X
authors.lastname: Wang
mesh_terms: D000538:Aluminum Silicates / Q000737:chemistry*; D005063:Europium / Q000737:chemistry*; D006812:Humic Substances; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D008903:Minerals / Q000737:chemistry*; D010316:Particle Size; D056951:Photoelectron Spectroscopy; D033362:Powder Diffraction; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D056928:X-Ray Absorption Spectroscopy
chemical_list: D000538:Aluminum Silicates; D006812:Humic Substances; D008903:Minerals; C546376:rectorite; D005063:Europium