title: Mn-Ce oxide as a high-capacity adsorbent for fluoride removal from water.
abstract: A novel Mn-Ce oxide adsorbent with high sorption capacity for fluoride was prepared via co-precipitation method in this study, and the granular adsorbent was successfully prepared by calcining the mixture of the Mn-Ce powder and pseudo-boehmite. High-resolution transmission electron microscopy (TEM) image showed that the Mn-Ce adsorbent consisted of about 4.5 nm crystals, and X-ray diffraction (XRD) analysis indicated the formation of solid solution by Mn species entering CeO(2) lattices. The surface hydroxyl group density on the Mn-Ce adsorbent was determined to be as high as 15.3 mmol g(-1), mainly responsible for its high sorption capacity for fluoride. Sorption isotherms showed that the sorption capacities of fluoride on the powdered and granular adsorbent were 79.5 and 45.5 mg g(-1) respectively at the equilibrium fluoride concentration of 1 mg L(-1), much higher than all reported adsorbents. Additionally, the adsorption was fast within the initial 1 h. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis revealed that the hydroxyl groups on the adsorbent surface were involved in the sorption of fluoride. Both anion exchange and electrostatic interaction were involved in the sorption of fluoride on the Mn-Ce oxide adsorbent.
authors.affiliation: Department of Environmental Science and Engineering, Tsinghua University, Beijing 100084, China. dengshubo@tsinghua.edu.cn
authors.forename: Shubo
authors.initials: S
authors.lastname: Deng
authors.forename: Han
authors.initials: H
authors.lastname: Liu
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.forename: Jun
authors.initials: J
authors.lastname: Huang
authors.forename: Gang
authors.initials: G
authors.lastname: Yu
mesh_terms: D000327:Adsorption; D000536:Aluminum Hydroxide / Q000737:chemistry; D000537:Aluminum Oxide / Q000737:chemistry; D002563:Cerium / Q000737:chemistry*; D005459:Fluorides / Q000302:isolation & purification*; D007700:Kinetics; D017895:Manganese Compounds / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission; D010087:Oxides / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D011208:Powders; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D013816:Thermodynamics; D018508:Water Purification / Q000379:methods*; D014881:Water Supply / Q000032:analysis*; D014961:X-Ray Diffraction
chemical_list: D017895:Manganese Compounds; D010087:Oxides; D011208:Powders; D002563:Cerium; D000536:Aluminum Hydroxide; C030583:ceric oxide; C069471:aluminum oxide hydroxide; C027424:manganese oxide; D000537:Aluminum Oxide; D005459:Fluorides