INCDO-INOE 2000, Research Institute for Analytical Instrumentation, 67 Donath Street, 400293 Cluj-Napoca, Romania.
GeoPlus Services SRL, 99D Braniste Street, 407310 Gilau, Romania.
Molecules. 2022 May 30;27(11):3503. doi: 10.3390/molecules27113503.
In the present work, the capability of the volcanic tuff from Macicasu (Romania) to remove ammonia (NH) from air with different contamination levels during 24 h of adsorption experiments was investigated. The natural zeolitic volcanic tuff was characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), the Brunauer-Emmett-Teller (BET) method, inductively coupled plasma optical emission spectrometry (ICP-OES), and thermogravimetric analysis (TGA). The adsorption capacities varied between 0.022 mg NH g zeolite and 0.282 mg NH g zeolite, depending on the NH concentrations in the air and at the contact time. The nonlinear forms of the Langmuir and Freundlich isotherm models were used to fit the experimental data. Additionally, the adsorption of NH was studied using nonlinear pseudo-first-order (PFO), pseudo-second-order (PSO), and Elovich kinetic model. Based on the total volume of pores of used volcanic tuff, the NH was removed from the air both due to the physical adsorption of NH gas and the ion exchange of NH (resulted from a reaction between NH and HO adsorbed by the zeolite). Depending on the initial NH concentration and the amount of volcanic tuff, the NH concentrations can be reduced below the threshold of this contaminant in the air. The adsorption capacity of NH per unit of zeolite (1 g) varied in the range of 0.022-0.282 mg NH g depending on the NH concentration in the air.
在本工作中，研究了来自罗马尼亚 Macicasu 的火山凝灰岩在 24 小时吸附实验中去除空气中不同污染水平氨（NH）的能力。采用 X 射线衍射（XRD）、扫描电子显微镜（SEM）、BET 法、电感耦合等离子体发射光谱（ICP-OES）和热重分析（TGA）对天然沸石火山凝灰岩进行了表征。吸附容量在 0.022mg NH g 沸石和 0.282mg NH g 沸石之间变化，这取决于空气中的 NH 浓度和接触时间。Langmuir 和 Freundlich 等温线模型的非线性形式被用来拟合实验数据。此外，还使用非线性拟一级（PFO）、拟二级（PSO）和 Elovich 动力学模型研究了 NH 的吸附。基于使用的火山凝灰岩的总孔体积，NH 既可以通过 NH 气体的物理吸附，也可以通过 NH（由 NH 与沸石吸附的 HO 之间的反应产生）的离子交换从空气中去除。根据初始 NH 浓度和火山凝灰岩的量，可以将空气中的 NH 浓度降低到该污染物的阈值以下。单位沸石（1g）的 NH 吸附容量在 0.022-0.282mg NH g 之间变化，这取决于空气中的 NH 浓度。
