Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul, 04763, Republic of Korea.
Department of Civil and Environmental Engineering, Hanyang University, 222 Wangsimni-Ro, Seoul, 04763, Republic of Korea.
Environ Res. 2020 Mar;182:109043. doi: 10.1016/j.envres.2019.109043. Epub 2019 Dec 17.
Various materials have been investigated for the adsorptive removal of volatile organic compounds (VOCs, such as benzene). However, most materials proposed for the adsorptive removal of gaseous benzene (and other VOCs) perform relatively poorly (e.g., an impractically low-service 10% breakthrough volume [BTV10] at < 100 ppm). The adsorbent uptake rate (mg g min) can also be assessed as a function of the gas-stream flow rate (or space velocity). The main aim of this study is to explore the effect of two different gas-stream supply modes - stopped flow (at a fixed stream flow rate of 330 mL atm min) vs. continuous flow (a variable-stream flow rate of 100, 200, or 330 mL atm min) on the adsorption metrics of gaseous benzene on 5 mg of two types of - II covalent organic polymers (COPs: CBAP-1 [DETA], CD; or CBAP-1 [EDA], CE). The sorbent tube outlet stream was sampled by two respective sampling methods (i.e., a large-volume injector [LVI] for stopped flow vs. syringe injection [SI] for continuous flow) for sample quantitation by gas chromatography flame-ionization detection (GC-FID). The observed BTV10 values in the two sampling modes were similar when tested using 10 ppm benzene, irrespective of sorbents: 56/60 (CD) vs. 620/624 L atm g (CE). BTV10 values increased systematically with decreasing stream-flow rates to reflect the importance of space velocity in adsorptive removal of benzene. The overall assessment of adsorption performance between stopped flow (LVI) and continuous flow (SI) revealed that the performance of the adsorbent is independent of flow mode (e.g., when performance was compared at flow rate of 330 mL min).
各种材料已被用于吸附去除挥发性有机化合物（VOC，如苯）。然而，大多数用于吸附去除气态苯（和其他 VOC）的材料性能相对较差（例如，在 < 100 ppm 时，实际应用中 10%穿透体积[BTV10]非常低）。吸附剂的吸附速率（mg g min）也可以作为气流速率（或空间速度）的函数进行评估。本研究的主要目的是探索两种不同的气流供应模式——停流（固定气流速率为 330 mL atm min）与连续流（100、200 或 330 mL atm min 的可变气流速率）对两种类型的 - II 共价有机聚合物（COPs：CBAP-1 [DETA]，CD；或 CBAP-1 [EDA]，CE）吸附气态苯的吸附性能的影响。通过两种不同的取样方法（即停流时的大体积进样器[LVI]与连续流时的注射器进样[SI]）对吸附剂管出口流进行取样，然后通过气相色谱火焰离子化检测（GC-FID）进行定量分析。使用 10 ppm 苯进行测试时，两种取样模式下的 BTV10 值相似，与吸附剂无关：56/60（CD）与 620/624 L atm g（CE）。BTV10 值随着气流速率的降低而系统地增加，这反映了空间速度在吸附去除苯中的重要性。停流（LVI）和连续流（SI）之间吸附性能的总体评估表明，吸附剂的性能不依赖于流动模式（例如，在 330 mL min 的流速下进行性能比较时）。
