Department of Mining Engineering, Faculty of Engineering, Afyon Kocatepe University, 03200, Afyonkarahisar, Turkey.
Department of Civil and Environmental Engineering, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, UK.
Environ Sci Pollut Res Int. 2017 Sep;24(27):21680-21692. doi: 10.1007/s11356-017-9524-1. Epub 2017 Jul 29.
This paper investigates the sorption characteristics and mechanisms of pyrene onto two types of natural sepiolite-brown (B-Sep) and white (W-Sep). The effects of relevant properties such as clay content, surface area, pore diameter and volume, divalent cations, and organic carbon content were investigated by single component batch adsorption systems. The results suggest that pyrene has high affinity for both sepiolite and its sorption behavior could be mainly affected by exchangeable strongly hydrated cations such as Ca and HO in the zeolite-like channels and by open channel defects (OCD) structures but no so much by the large number of Si-OH groups located on the sepiolite's basal surfaces. Mesoporosity rather than surface area largely controls the sorption capacity and intensity of both sepiolites. This is shown by the increase in pore volume that exhibited the greatest increase in BET surface area. Particle size and morphological changes of both sepiolites following pyrene adsorption determined by FE-SEM showed that the sepiolite fibers are much longer than their widths, which are only several laths (several nanometers). This is a result of growth, mostly along the c-axis, at the expense of the diffusion of pyrene molecules through aqueous solution. As a consequence, a significant fibrous morphology is produced following the adsorption of pyrene by both sepiolites.
本论文研究了蒽在两种天然海泡石（B-Sep 和 W-Sep）上的吸附特性和机制。通过单组分批吸附系统，研究了粘土含量、表面积、孔径和体积、二价阳离子和有机碳含量等相关性质对吸附的影响。结果表明，蒽对海泡石具有高亲和力，其吸附行为主要受沸石样通道中可交换的强水合阳离子（如 Ca 和 HO）以及开放通道缺陷（OCD）结构的影响，而受位于海泡石基面的大量 Si-OH 基团的影响较小。中孔而不是表面积在很大程度上控制了两种海泡石的吸附容量和强度。这可以通过孔体积的增加得到证明，孔体积的增加使 BET 表面积的增加最大。FE-SEM 测定的蒽吸附后两种海泡石的粒径和形态变化表明，海泡石纤维的长度远远大于其宽度，仅为几个薄片（几个纳米）。这是由于蒽分子通过水溶液的扩散受阻，海泡石主要沿 c 轴生长的结果。因此，蒽被两种海泡石吸附后，都会产生明显的纤维形态。
