Four naturally occurring zeolites were examined to verify their assignments as chabazites AZLB-Ca and AZLB-Na (Bowie, Arizona) and clinoptilolites NM-Ca (Winston, New Mexico) and NV-Na (Ash Meadows, Nevada). Based on powder X-ray diffraction, NM-Ca was discovered to be mostly quartz with some clinoptilolite residues. Treatment with concentrated HCl (12.1 M) acid resulted in AZLB-Ca and AZLB-Na, the chabazite-like species, becoming amorphous, as confirmed by powder X-ray diffraction. In contrast, NM-Ca and NV-Na, which are clinoptilolite-like species, withstood boiling in concentrated HCl acid. This treatment removes calcium, magnesium, sodium, potassium, aluminum, and iron atoms or ions from the framework while leaving the silicon framework intact as confirmed via X-ray fluorescence and diffraction. SEM images on calcined and HCl treated NV-Na were obtained. BET surface area analysis confirmed an increase in surface area for the two zeolites after treatment, NM-Ca 20.0(1) to 111(4) m²/g and NV-Na 19.0(4) to 158(7) m²/g. ²⁹Si and ²⁷Al MAS NMR were performed on the natural and treated NV-Na zeolite, and the data for the natural NV-Na zeolite suggested a Si:Al ratio of 4.33 similar to that determined by X-Ray fluorescence of 4.55. Removal of lead ions from solution decreased from the native NM-Ca, 0.27(14), NV-Na, 1.50(17) meq/g compared to the modified zeolites, 30 min HCl treated NM-Ca 0.06(9) and NV-Na, 0.41(23) meq/g, and also decreased upon K⁺ ion pretreatment in the HCl modified zeolites.

中文翻译：

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来自内华达州、新墨西哥州和亚利桑那州的天然沸石的盐酸改性和铅去除研究

检查了四种天然存在的沸石，以验证它们作为菱沸石 AZLB-Ca 和 AZLB-Na（鲍伊，亚利桑那州）和斜发沸石 NM-Ca（温斯顿，新墨西哥州）和 NV-Na（内华达州阿什梅多斯）的分配。基于粉末 X 射线衍射，发现 NM-Ca 主要是石英，带有一些斜发沸石残留物。用浓 HCl (12.1 M) 酸处理导致 AZLB-Ca 和 AZLB-Na（菱沸石样物质）变成无定形，如粉末 X 射线衍射所证实。相比之下，NM-Ca 和 NV-Na 是类似斜发沸石的物种，在浓盐酸中经受住了沸腾。这种处理从骨架中去除了钙、镁、钠、钾、铝和铁原子或离子，同时通过 X 射线荧光和衍射证实，硅骨架完好无损。获得了煅烧和 HCl 处理的 NV-Na 的 SEM 图像。BET 表面积分析证实处理后两种沸石的表面积增加，NM-Ca 20.0(1) 至 111(4) m² /g和NV-Na 19.0(4)至158(7)m ² /g。对天然和处理过的 NV-Na 沸石进行²⁹ Si 和²⁷ Al MAS NMR，天然 NV-Na 沸石的数据表明 Si:Al 比为 4.33，与 X 射线荧光测定的结果相似，为 4.55。与改性沸石、30 分钟 HCl 处理的 NM-Ca 0.06(9) 和 NV-相比，从溶液中去除铅离子从天然 NM-Ca、0.27(14)、NV-Na、1.50(17) meq/g 降低Na，0.41(23) meq/g，并且在 HCl 改性沸石中K ⁺离子预处理后也降低。