Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, 04763, Republic of Korea.
Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, 04763, Republic of Korea; Analysis and Evaluation Department, Egyptian Petroleum Research Institute, Nasr City, 11727 Cairo, Egypt.
J Hazard Mater. 2023 Jun 5;451:131203. doi: 10.1016/j.jhazmat.2023.131203. Epub 2023 Mar 15.
The potential utility of titanium oxynitride doped with 5% zinc (ZnTON) has been investigated as an adsorbent for the treatment of gaseous formaldehyde (FA) using a fixed-bed adsorption system. The adsorption capacity of ZnTON, when estimated at 10%/100% breakthrough (BT) levels from a dry feed gas consisting of 10 Pa FA, was far superior to two reference materials (i.e., commercial P25-TiO and activated carbon (AC)) by factors of 1.7/1.3 and 10/2.5, respectively. The adsorption capacity of ZnTON increased with the increase in the initial feeding concentration of FA (5-12.5 Pa), while decreasing with the rising temperature (25-100 C). An increase in moisture level (0-100% relative humidity) also led to 5.4- and 2.5-fold reductions in adsorption capacity of ZnTON at 10% and 100% BT levels, respectively. Thermodynamically, the adsorption of FA onto ZnTON is an exothermic (ΔH = - 9.69 kJ.mol) to be feasible in nature based on physisorption mechanism. Further, the adsorption of FA onto ZnTON was governed by surface interactions and monolayer surface coverage (Van der Waal's force/electrostatic attraction), as it obeyed the Langmuir isotherm and pseudo-second-order kinetic models. Regeneration tests indicated a positive effect of moisture on FA desorption and durability of ZnTON (i.e., over three adsorption-desorption cycles). This study offers valuable mechanistic insights into the synthesis of an advanced adsorbent for the efficient removal of hazardous volatile organic compounds under near-ambient conditions.
掺 5%锌的氮化钛氧（ZnTON）作为一种吸附剂，用于处理含有 10 Pa 甲醛（FA）的干进料气体的固定床吸附系统，研究了其潜在的应用。与两种参考材料（即商业 P25-TiO 和活性炭（AC））相比，当在 10%/100%穿透（BT）水平下估计 ZnTON 的吸附能力时，其吸附能力分别高出 1.7/1.3 和 10/2.5 倍。ZnTON 的吸附能力随 FA 的初始进料浓度（5-12.5 Pa）的增加而增加，随温度（25-100°C）的升高而降低。湿度水平（0-100%相对湿度）的增加也分别导致 ZnTON 在 10%和 100% BT 水平下的吸附能力降低 5.4-和 2.5 倍。从热力学角度来看，FA 在 ZnTON 上的吸附是放热的（ΔH = -9.69 kJ.mol），基于物理吸附机制，在自然界中是可行的。此外，FA 在 ZnTON 上的吸附受表面相互作用和单层表面覆盖（范德华力/静电吸引）的控制，因为它符合朗缪尔等温线和准二级动力学模型。再生试验表明，水分对 FA 解吸和 ZnTON 的耐用性有积极影响（即在三个吸附-解吸循环后）。这项研究为在近环境条件下有效去除有害挥发性有机化合物的先进吸附剂的合成提供了有价值的机理见解。
