title: Adsorption isotherms and kinetics of activated carbons produced from coals of different ranks.
abstract: Activated carbons (ACs) from six coals, ranging from low-rank lignite brown coal to high-rank stone coal, were utilized as adsorbents to remove basic methylene blue (MB) from an aqueous solution. The surface properties of the obtained ACs were characterized via thermal analysis, N2 isothermal sorption, scanning electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and Boehm titration. As coal rank decreased, an increase in the heterogeneity of the pore structures and abundance of oxygen-containing functional groups increased MB coverage on its surface. The equilibrium data ﬁtted well with the Langmuir model, and adsorption capacity of MB ranged from 51.8 to 344.8 mg g⁻¹. Good correlation coefficients were obtained using the intra-particle diffusion model, indicating that the adsorption of MB onto ACs is diffusion controlled. The values of the effective diffusion coefficient ranged from 0.61 × 10⁻¹⁰ to 7.1 × 10⁻¹⁰ m² s⁻¹, indicating that ACs from lower-rank coals have higher effective diffusivities. Among all the ACs obtained from selected coals, the AC from low-rank lignite brown coal was the most effective in removing MB from an aqueous solution.
authors.affiliation: Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia.
authors.forename: B
authors.initials: B
authors.lastname: Purevsuren
authors.affiliation: Department of Environmental Engineering, National Ilan University, 1, Sec. 1, Shen-Lung Road, I-Lan, 260, Taiwan.
authors.forename: Chin-Jung
authors.initials: CJ
authors.lastname: Lin
authors.affiliation: Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia.
authors.forename: Y
authors.initials: Y
authors.lastname: Davaajav
authors.affiliation: Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia.
authors.forename: A
authors.initials: A
authors.lastname: Ariunaa
authors.affiliation: Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia.
authors.forename: S
authors.initials: S
authors.lastname: Batbileg
authors.affiliation: Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia.
authors.forename: B
authors.initials: B
authors.lastname: Avid
authors.affiliation: Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia.
authors.forename: S
authors.initials: S
authors.lastname: Jargalmaa
authors.affiliation: Department of Environmental Engineering, National Ilan University, 1, Sec. 1, Shen-Lung Road, I-Lan, 260, Taiwan.
authors.forename: Yu
authors.initials: Y
authors.lastname: Huang
authors.affiliation: Department of Geosciences, National Taiwan University, P.O. Box 13-318, Taipei 106, Taiwan E-mail: yhliou@ntu.edu.tw.
authors.forename: Sofia Ya-Hsuan
authors.initials: SY
authors.lastname: Liou
mesh_terms: D000327:Adsorption; D002244:Carbon / Q000737:chemistry*; D003031:Coal / Q000032:analysis*; D007700:Kinetics; D008751:Methylene Blue / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D056951:Photoelectron Spectroscopy; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D003031:Coal; D014874:Water Pollutants, Chemical; D002244:Carbon; D008751:Methylene Blue