title: Porous nano-cerium oxide wood chip biochar composites for aqueous levofloxacin removal and sorption mechanism insights.
abstract: The adsorption removal of levofloxacin (LEV), a widely used fluoroquinolone antibiotic, by using the biochars derived from the pyrolysis of pine wood chip pretreated with cerium trichloride was investigated through batch sorption experiments and multiple characterization techniques. The differences in the basic physicochemical properties between Ce-impregnated biochars and the pristine biochars were confirmed by the analysis of elemental compositions, specific surface areas, energy dispersive spectrometry, X-ray diffraction, and thermo-gravimetry. FT-IR spectra of the pre- and post-sorption biochars confirmed the chemical adsorption for LEV sorption onto the biochars. Large shifts in the binding energy of Ce3d, O1s, C1s, and N1sregions on the pre- and post-sorption biochars indicated the surface complexation of LEV molecule onto the biochars. The binding species of Ce4+and Ce3+identified by X-ray photoelectron spectroscopy reflect the role of Ce oxides during sorption. Batch adsorption showed the significant enhancement of adsorption capacity for LEV after the Ce modification. Batch adsorption kinetic data fitted well with the pseudo-second-order model. Both the Langmuir and the Freundlich models reproduced the isotherm data well. Findings from this work indicated that Ce-impregnated biochars can be effective for the removal of aqueous LEV.
authors.affiliation: Key Laboratory of Surficial Geochemistry (Ministry of Education), Hydrosciences Department, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China.
authors.forename: Shengze
authors.initials: S
authors.lastname: Yi
authors.affiliation: Key Laboratory of Surficial Geochemistry (Ministry of Education), Hydrosciences Department, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Sun
authors.affiliation: Center of Material Analysis and School of Chemistry and Chemical Engineering, State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, 20 Hankou Road, Nanjing, 210093, People's Republic of China. huxin@nju.edu.cn.
authors.forename: Xin
authors.initials: X
authors.lastname: Hu
authors.affiliation: Key Laboratory of Surficial Geochemistry (Ministry of Education), Hydrosciences Department, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China.
authors.forename: Hongxia
authors.initials: H
authors.lastname: Xu
authors.affiliation: Agricultural and Biological Engineering Department, University of Florida, Gainesville, FL, 32611, USA.
authors.forename: Bin
authors.identifier: http://orcid.org/0000-0003-3769-0191
authors.initials: B
authors.lastname: Gao
authors.affiliation: Key Laboratory of Surficial Geochemistry (Ministry of Education), Hydrosciences Department, School of Earth Sciences and Engineering, Nanjing University, Nanjing, 210023, China. jcwu@nju.edu.cn.
authors.forename: Jichun
authors.initials: J
authors.lastname: Wu
mesh_terms: D000327:Adsorption; D002563:Cerium / Q000737:chemistry*; D002606:Charcoal; D007700:Kinetics; D064704:Levofloxacin / Q000737:chemistry*; D049329:Nanostructures; D016062:Porosity; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification; D014934:Wood / Q000737:chemistry*
chemical_list: D014874:Water Pollutants, Chemical; C540010:biochar; D002606:Charcoal; D002563:Cerium; C030583:ceric oxide; D064704:Levofloxacin
keywords: Biochar; Impregnation; Levofloxacin; Multiple characterizations; Sorption mechanism