Purevsuren B, Lin Chin-Jung, Davaajav Y, Ariunaa A, Batbileg S, Avid B, Jargalmaa S, Huang Yu, Liou Sofia Ya-Hsuan
Institute of Chemistry and Chemical Technology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia.
Department of Environmental Engineering, National Ilan University, 1, Sec. 1, Shen-Lung Road, I-Lan, 260, Taiwan.
Water Sci Technol. 2015;71(8):1189-95. doi: 10.2166/wst.2015.094.
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.
六种煤制得的活性炭（ACs），从低阶褐煤到高阶石煤，被用作吸附剂以从水溶液中去除碱性亚甲基蓝（MB）。通过热分析、N₂等温吸附、扫描电子显微镜、傅里叶变换红外光谱、X射线光电子能谱和 Boehm 滴定对所得ACs的表面性质进行了表征。随着煤阶降低，孔隙结构的不均匀性增加以及含氧官能团的丰度增加，使得MB在其表面的覆盖率提高。平衡数据与Langmuir模型拟合良好，MB的吸附容量范围为51.8至344.8 mg g⁻¹。使用颗粒内扩散模型获得了良好的相关系数，表明MB在ACs上的吸附受扩散控制。有效扩散系数的值范围为0.61×10⁻¹⁰至7.1×10⁻¹⁰ m² s⁻¹，表明低阶煤制得的ACs具有更高的有效扩散率。在从选定煤中获得的所有ACs中，低阶褐煤制得的AC在从水溶液中去除MB方面最有效。
