This study used coal fly ash (CFA) to synthesize nano-zeolite for sulfate removal from aqueous solutions at neutral pH. The zeolitic material was synthesized by hydrothermic treatment of CFA with a 2 M NaOH solution and the synthezised zeolites were modified to enhance the surface charge and characterized pre and post-sulfate adsorption using XRF, XRD, FTIR, SEM-EDS and BET to identify the crystalline and microstructural alterations. The BET analysis showed a surface area of 85.53 m/g and 1.059 m/g for the modified zeolites and the CFA respectively. Sulfate adsorption investigations demonstrated that 10 g/L was the optimum adsorbent dosage and zeolites had the maximum adsorption capacity of 42.25 mg/g and fitted well into second order kinetic model. Correlated with the morphology, surface charge, mineralogy, composition and kinetic studies, the results demonstrated that the synthesized zeolites are suitable to uptake sulfate ions from the wastewater. The results of this study showed that nano-zeolites can be synthesized from CFA and can be used in the removal of sulfates from synthetic wastewater at room temperatures.

中文翻译：

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粉煤灰纳米沸石的合成、改性及表征用于去除废水中的硫酸盐

本研究使用粉煤灰 (CFA) 合成纳米沸石，用于在中性 pH 值下去除水溶液中的硫酸盐。通过用 2 M NaOH 溶液水热处理 CFA 来合成沸石材料，并对合成的沸石进行改性以增强表面电荷，并使用 XRF、XRD、FTIR、SEM-EDS 和 BET 对硫酸盐吸附前后进行表征，以鉴定晶体和微观结构的改变。BET 分析显示改性沸石和 CFA 的表面积分别为 85.53 m/g 和 1.059 m/g。硫酸盐吸附研究表明，10 g/L 是最佳吸附剂用量，沸石的最大吸附容量为 42.25 mg/g，并且很好地符合二级动力学模型。与形态、表面电荷、矿物学、组成和动力学研究相关，结果表明合成的沸石适合从废水中吸收硫酸根离子。这项研究的结果表明，纳米沸石可以由CFA合成，并可用于在室温下去除合成废水中的硫酸盐。