Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, 475004, China.
Institute of Environmental and Analytical Sciences, College of Chemistry and Chemical Engineering, Henan University, Kaifeng, 475004, China.
J Environ Manage. 2019 Feb 1;231:391-396. doi: 10.1016/j.jenvman.2018.10.072. Epub 2018 Oct 24.
A low-cost mercapto-modified coal gangue (CG-SH) was fabricated by modification of coal gangue (CG) with (3-mercaptopropyl) trimethoxysilane. The structure and composition for as-prepared CG-SH were characterized by using X-ray diffraction (XRD), Fourier transfer infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray fluorescence (XRF). Results indicated that larger amounts of mercapto-groups (-SH) was successfully introduced onto CG, which followed by acted as active sites for the removal of heavy metal cations, such as Pb(II), Cd(II) and Hg(II). The factors that affected the adsorption equilibrium as well as the removal efficiency, i.e., contact time, initial concentration, pH and temperature, were investigated in detail. The adsorption isotherms for Pb(II), Cd(II) and Hg(II) were well fitted with Langmuir model. The maximum adsorption capacity of CG-SH for Pb(II), Cd(II) and Hg(II) were calculated to be 332.8, 110.4 and 179.2 mg g, respectively. The adsorption for Pb(II), Cd(II) and Hg(II) on CG-SH could be well described by pseudo-second-order kinetic model. And thermodynamic analysis suggests that the adsorption process for Pb(II) is exothermal, while that for Cd(II) and Hg(II) are endothermal. The results suggest CG-SH have great potential to be used as efficient absorbent for the removal of heavy metal cations from water.
一种低成本的巯基改性煤矸石（CG-SH）是通过（3-巯丙基）三甲氧基硅烷对煤矸石（CG）进行改性制备的。采用 X 射线衍射（XRD）、傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）和 X 射线荧光光谱（XRF）对所制备的 CG-SH 的结构和组成进行了表征。结果表明，大量的巯基（-SH）成功地接枝到 CG 上，随后作为活性位点，用于去除重金属阳离子，如 Pb(II)、Cd(II)和 Hg(II)。详细研究了影响吸附平衡和去除效率的因素，如接触时间、初始浓度、pH 值和温度。Pb(II)、Cd(II)和 Hg(II)的吸附等温线很好地符合 Langmuir 模型。CG-SH 对 Pb(II)、Cd(II)和 Hg(II)的最大吸附容量分别计算为 332.8、110.4 和 179.2mg/g。Pb(II)、Cd(II)和 Hg(II)在 CG-SH 上的吸附可以很好地用拟二级动力学模型描述。热力学分析表明，Pb(II)的吸附过程是放热的，而 Cd(II)和 Hg(II)的吸附过程是吸热的。这些结果表明 CG-SH 具有很大的潜力，可作为一种有效的吸附剂，用于从水中去除重金属阳离子。
