Hebei Key Laboratory of Inorganic Nanomaterials, College of Chemistry and Material Science, Hebei Normal University, Shijiazhuang 050024, Hebei, PR China.
College of Pharmaceutical Sciences, Hebei Medical University, Shijiazhuang 050017, Hebei, PR China.
J Hazard Mater. 2021 May 5;409:124965. doi: 10.1016/j.jhazmat.2020.124965. Epub 2020 Dec 25.
The three types of silica supported sulfuric acids (SSA), with the same sulfuric acid loading of 9.25 mmol g, were prepared by a wet impregnation method from silica gel (SG), SBA-15 and MCM-41. Characterization of the prepared SSA showed that two anchoring states coexisted for sulfuric acid supported on the surface of the silicas: A physiosorbed (P)-state sulfuric acid; and a chemically bonded (C)-state sulfuric acid. Dynamic adsorption results showed that each SSA had a significant removal capacity for o-xylene gas in the reactive temperature regions. The ranges of the reactive regions were 120-220 °C (SSA/SG), 120-230 °C (SSA/SBA-15) and 120-250 °C (SSA/MCM-41), and this could be attributed to the sulfonation reaction between o-xylene and the anchored sulfuric acid. SSA/MCM-41 showed the highest theoretical breakthrough adsorption capacity (Q, 526.71 mg g) compared with SSA/SBA-15 (363.54 mg g) and SSA/SG (239.15 mg g). Q was closely associated with the amount or proportion of the C-state sulfuric acid on the surface of each SSA. Optimum breakthrough time and Q was obtained by increasing the bed height and decreasing flow rate and inlet concentration. The SSA exhibited excellent recyclability and reuse performance over eight consecutive adsorption/desorption/regeneration cycles. The results suggested that the SSA, especially SSA/MCM-41, might have good potential in applications using adsorbents for the removal of BTEX pollutants.
三种类型的硅胶负载硫酸（SSA），硫酸负载量均为 9.25mmol/g，通过硅胶（SG）、SBA-15 和 MCM-41 的湿浸渍法制备。对制备的 SSA 的表征表明，硫酸在硅表面以两种锚固状态共存：物理吸附（P）态硫酸；和化学结合（C）态硫酸。动态吸附结果表明，每种 SSA 在反应温度区域内对邻二甲苯气体都有显著的去除能力。反应区域的范围为 120-220°C（SSA/SG）、120-230°C（SSA/SBA-15）和 120-250°C（SSA/MCM-41），这可以归因于邻二甲苯与锚固硫酸之间的磺化反应。与 SSA/SBA-15（363.54mg/g）和 SSA/SG（239.15mg/g）相比，SSA/MCM-41 显示出最高的理论穿透吸附容量（Q，526.71mg/g）。Q 与每种 SSA 表面 C 态硫酸的量或比例密切相关。通过增加床层高度、降低流速和入口浓度，可以获得最佳的穿透时间和 Q。SSA 在连续 8 次吸附/解吸/再生循环中表现出优异的可回收性和再利用性能。结果表明，SSA，特别是 SSA/MCM-41，在使用吸附剂去除 BTEX 污染物的应用中可能具有良好的应用潜力。
