In this work, the surfactant-modified natural zeolite (SMZ) as a low-cost and eco-friendly adsorbent have been used for the removal of Eosin Y or Acid Red 87 (AR87) and Basic Red 46 (BR46) dyes from aqueous solutions. In order to modify the surface of zeolite, a new approach was proposed based on the surface properties of the surfactants. Two cationic surfactants with the same head group structure and different alkyl chain length (dodecylpyridinium chloride, DPC and tetradecylpyridinium chloride, TPC) were investigated using surface tension measurements and then surfactant TPC was selected as the better option for the preparation of modified zeolite. Natural and modified zeolite are characterized with Fourier transform infrared spectroscopy (FT–IR), BET surface area analysis, thermogravimetric analysis (TGA), pore volume measurement, XRD, the scanning electron microscopy (SEM) images and Zeta potential techniques. To identify the performance of the surfactant modified zeolite (SMZ) in the removal of ionic compounds were selected two different types of dyes with oppositely charged head groups (AR87: anionic and BR46: cationic). The adsorption equilibrium and kinetic data were analyzed using different models (ten isotherms and eight kinetic models in nonlinear forms). The rate of removal of dyes by SMZ shows two different ranges, very fast for AR87 (less than 5 min) and slow for BR46 (45 min.). The maximum adsorption capacity () are 21.02 and 8.62 mg/g for removal of AR87 and BR46, respectively. The results indicate that SMZ can be used as efficient adsorbent for the removal of the anionic dyes such as AR87 form aqueous solutions.

中文翻译：

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利用表面研究选择更好的沸石改性阳离子表面活性剂及其在阴阳离子染料去除中的应用


在这项工作中，表面活性剂改性的天然沸石（SMZ）作为一种低成本且环保的吸附剂已用于去除水溶液中的曙红Y或酸性红87（AR87）和碱性红46（BR46）染料。为了对沸石表面进行改性，基于表面活性剂的表面性质，提出了一种新的方法。通过表面张力测量研究了两种具有相同头基结构和不同烷基链长度的阳离子表面活性剂（十二烷基氯化吡啶，DPC和十四烷基氯化吡啶，TPC），然后选择表面活性剂TPC作为制备改性沸石的更好选择。天然和改性沸石通过傅里叶变换红外光谱 (FT-IR)、BET 表面积分析、热重分析 (TGA)、孔体积测量、XRD、扫描电子显微镜 (SEM) 图像和 Zeta 电位技术进行表征。为了确定表面活性剂改性沸石 (SMZ) 在去除离子化合物方面的性能，选择了两种不同类型的具有相反电荷头基的染料（AR87：阴离子和 BR46：阳离子）。使用不同的模型（十个等温线和八个非线性形式的动力学模型）分析吸附平衡和动力学数据。 SMZ 去除染料的速率显示出两个不同的范围，AR87 非常快（小于 5 分钟），BR46 则很慢（45 分钟）。去除 AR87 和 BR46 的最大吸附容量 () 分别为 21.02 和 8.62 mg/g。结果表明，SMZ 可以作为有效的吸附剂去除水溶液中的 AR87 等阴离子染料。