Abstract

The goal of this study was to investigate the effect of thermal treatment (200, 400, and 600 °C) on the adsorption capacity of a natural clinoptilolite-rich zeolite (NZ) of different particle sizes for methylene blue removal from aqueous solution. The physical properties and chemical composition of the natural zeolites treated at several temperatures were determined. Powder X-ray diffraction, Brunauer–Emmett–Teller, and scanning electron microscopy were used to characterize the thermally treated zeolites. X-ray diffraction showed that the main crystalline phases of the thermally treated zeolites were clinoptilolite-Na, quartz, muscovite, and albite. The equilibrium measurements were analyzed using Langmuir, Freundlich, and Dubinin-Radushkevich isotherms. The experimentally fitted Freundlich isotherm was a better fit than the Langmuir model for methylene blue adsorption onto the thermally treated zeolites. The adsorption of methylene blue on the thermally treated natural zeolites was shown to involve chemisorption.

摘要

本研究的目的是研究热处理（200、400 和 600 °C）对不同粒径的天然富含斜发沸石 (NZ) 的吸附能力的影响，以从水溶液中去除亚甲基蓝。测定了在几个温度下处理的天然沸石的物理性质和化学成分。粉末 X 射线衍射、Brunauer-Emmett-Teller 和扫描电子显微镜用于表征热处理过的沸石。X射线衍射表明热处理沸石的主要晶相是斜发沸石-钠、石英、白云母和钠长石。使用 Langmuir、Freundlich 和 Dubinin-Radushkevich 等温线分析平衡测量。实验拟合的 Freundlich 等温线比 Langmuir 模型更适合亚甲基蓝吸附到热处理沸石上。亚甲基蓝在热处理过的天然沸石上的吸附表明涉及化学吸附。