title: Phosphate adsorption on lanthanum loaded biochar.
abstract: To attain a low-cost and high-efficient phosphate adsorbent, lanthanum (La) loaded biochar (La-BC) prepared by a chemical precipitation method was developed. La-BC and its pristine biochar (CK-BC) were comparatively characterized using zeta potential, BET surface area, scanning electron microscopy/energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The adsorption ability and the mechanisms during adsorption process for the La-BC samples were also investigated. La loaded on the surface of biochar can be termed as La-composites (such as LaOOH, LaONO3 and La(OH)3), leading to the decrease of negative charge and surface area of biochar. La-BC exhibited the high adsorption capacity to phosphate compared to CK-BC. Adsorption isotherm and adsorption kinetic studies showed that the Langmuir isotherm and second order model could well describe the adsorption process of La-BC, indicating that the adsorption was dominated by a homogeneous and chemical process. The calculated maximum adsorption capacity was as high as 46.37 mg g(-1) (computed in P). Thermodynamic analysis revealed that the adsorption was spontaneous and endothermic. SEM, XRD, XPS and FT-IR analysis suggested that the multi-adsorption mechanisms including precipitation, ligand exchange and complexation interactions can be evidenced during the phosphate adsorption process by La-composites in La-BC.
authors.affiliation: Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, PR China; Institute of Ecological and Environmental Science, Sichuan Agricultural University, Sichuan 611130, PR China.
authors.forename: Zhanghong
authors.initials: Z
authors.lastname: Wang
authors.affiliation: Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, PR China. Electronic address: 101011398@seu.edu.cn.
authors.forename: Dekui
authors.initials: D
authors.lastname: Shen
authors.affiliation: Institute of Ecological and Environmental Science, Sichuan Agricultural University, Sichuan 611130, PR China. Electronic address: fishensjtu@gmail.com.
authors.forename: Fei
authors.initials: F
authors.lastname: Shen
authors.affiliation: Institute of Ecological and Environmental Science, Sichuan Agricultural University, Sichuan 611130, PR China.
authors.forename: Tianyu
authors.initials: T
authors.lastname: Li
mesh_terms: D000327:Adsorption; D002606:Charcoal / Q000737:chemistry*; D007700:Kinetics; D007811:Lanthanum / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010710:Phosphates / Q000737:chemistry*; D056951:Photoelectron Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D013816:Thermodynamics; D014961:X-Ray Diffraction
chemical_list: D010710:Phosphates; C540010:biochar; D002606:Charcoal; D007811:Lanthanum
keywords: Adsorption; Biochar; Lanthanum; Phosphate