Synthesis of NaY zeolite from coal gangue and its characterization for lead removal from solution

This work presents a method for synthesizing NaY zeolite from quartz abundant coal gangue through alkali fusion and hydrothermal processes. The synthesized zeolite was systematically characterized using X-ray fluorescence spectroscopy (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscope (HRTEM), selected area electron diffraction (SAED), Fourier-transform infrared (FTIR), and X-ray Photoelectron spectroscopy (XPS). Molar ratios of Na2O/SiO2 = 2.0, H2O/Na2O = 30, crystallization temperature 80 degrees C, and crystallization time 10-12 h were identified as the optimum synthesis parameters for producing well crystalized NaY zeolite from quartz abundant coal gangue. A total specific surface area, pore volume, and average pore diameter of the synthesized NaY were found to be 759.008 m 2 g(-1) , 0.318 cm(3) g(-1) , and 6.450 nm, respectively. The synthesized NaY presented high adsorption capacity for lead (Pb2+) removal from its contaminated water. Pb2+ removal efficiency of the original synthesized NaY zeolite was as high as 100% and more than 63.71% even after five adsorption/desorption cycles. The experimental adsorption data were well described by Langmuir isotherm and kinetics models. Adsorption and desorption rate constants were derived to be 6.18 x 10(-3) L mg(-1) min(-1) and 2.89 x 10(-3) min(-1) , respectively. Our experimental results revealed that ion exchange is the predominant mechanism for Pb2+ adsorption onto the NaY zeolite. (c) 2020 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

这项工作提出了一种通过碱熔和水热过程从富含石英的煤矸石合成NaY沸石的方法。利用X射线荧光光谱（XRF）、X射线衍射（XRD）、扫描电子显微镜（SEM）、高分辨率透射电子显微镜（HRTEM）、选区电子衍射（SAED）、傅里叶变换红外光谱（FTIR）和X射线光电子能谱（XPS）对合成的沸石进行了系统表征。确定了Na₂O/SiO₂ = 2.0、H₂O/Na₂O = 30、晶化温度80℃以及晶化时间10 - 12小时为从富含石英的煤矸石中生产结晶良好的NaY沸石的最佳合成参数。合成的NaY的总比表面积、孔体积和平均孔径分别为759.008 m² g⁻¹、0.318 cm³ g⁻¹和6.450 nm。合成的NaY对从受污染水中去除铅（Pb²⁺）表现出高吸附能力。原始合成的NaY沸石对Pb²⁺的去除效率高达100%，即使经过五次吸附/解吸循环，仍超过63.71%。实验吸附数据可以用朗缪尔等温线和动力学模型很好地描述。吸附和解吸速率常数分别为6.18×10⁻³ L mg⁻¹ min⁻¹和2.89×10⁻³ min⁻¹。我们的实验结果表明，离子交换是Pb²⁺吸附到NaY沸石上的主要机制。（c）2020日本粉末技术学会。由爱思唯尔出版社和日本粉末技术学会出版。保留所有权利。