Sulfur-impregnated zeolite has been obtained from the natural zeolite clinoptilolite by chemical modification with Na₂S at 150 °C. The purpose of zeolite impregnation was to enhance the sorption of Hg(II) from aqueous solutions. Chemical analysis, acid and basic properties determined by Bohem’s method, chemical behavior at different pH_o values, zeta potential, cation-exchange capacity (CEC), specific surface area, X-ray powder diffraction (XRPD), scanning electron microscopy with energy-dispersive X-ray analysis (SEM-EDS), Fourier transform infrared spectroscopy (FTIR), as well as thermogravimetry with derivative thermogravimetry (TG-DTG) were used for detailed comparative mineralogical and physico-chemical characterization of natural and sulfur-impregnated zeolites. Results revealed that the surface of the natural zeolite was successfully impregnated with sulfur species in the form of FeS and CaS. Chemical modification caused an increase in basicity and the net negative surface charge due to an increase in oxygen-containing functional groups as well as a decrease in specific surface area and crystallinity due to the formation of sulfur-containing clusters at the zeolite surface. The sorption of Hg(II) species onto the sulfur-impregnated zeolite was affected by the pH, solid/liquid ratio, initial Hg(II) concentration, and contact time. The optimal sorption conditions were determined as pH 2, a solid/liquid ratio of 10 g/L, and a contact time of 800 min. The maximum obtained sorption capacity of the sulfur-impregnated zeolite toward Hg(II) was 1.02 mmol/g. The sorption mechanism of Hg(II) onto the sulfur-impregnated zeolite involves electrostatic attraction, ion exchange, and surface complexation, accompanied by co-precipitation of Hg(II) in the form of HgS. It was found that sulfur-impregnation enhanced the sorption of Hg(II) by 3.6 times compared to the natural zeolite. The leaching test indicated the retention of Hg(II) in the zeolite structure over a wide pH range, making this sulfur-impregnated sorbent a promising material for the remediation of a mercury-polluted environment.

中文翻译：

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含硫天然沸石斜发沸石去除水溶液中Hg（II）的制备与表征

通过在150°C下用Na ₂ S进行化学改性，从天然沸石斜发沸石获得了硫浸渍的沸石。沸石浸渍的目的是增强水溶液中Hg（II）的吸附。化学分析，酸性和碱性性质在不同的pH来确定由Bohem的方法，化学行为_ö值，ζ电势，阳离子交换容量（CEC），比表面积，X射线粉末衍射（XRPD），带能量色散X射线分析的扫描电子显微镜（SEM-EDS），傅立叶变换红外光谱（FTIR） ，以及带导数热重分析的热重分析法（TG-DTG）用于天然和硫浸透沸石的详细比较矿物学和理化特征。结果表明，天然沸石的表面已成功地以FeS和CaS形式浸入了硫。由于含氧官能团的增加以及由于在沸石表面形成含硫团簇而引起的比表面积和结晶度的降低，化学改性导致碱度和净负表面电荷的增加。Hg（II）物质在硫浸渍沸石上的吸附受pH，固/液比，初始Hg（II）浓度和接触时间的影响。确定最佳吸附条件为pH 2，固/液比为10 g / L，接触时间为800分钟。硫浸渍的沸石对Hg（II）的最大吸附容量为1.02mmol / g。Hg（II）在硫磺浸渍沸石上的吸附机理涉及静电吸引，离子交换和表面络合，并伴随以HgS形式共沉淀Hg（II）。已经发现，与天然沸石相比，硫浸渍使Hg（II）的吸附提高了3.6倍。浸出试验表明，Hg（II）在较宽的pH范围内都保留在沸石结构中，