Department of Chemical & Materials Engineering, New Mexico State University, P.O. Box 30001, MSC 3805, Las Cruces, NM 88003, USA; Departamento de Química, Instituto Nacional de Investigaciones Nucleares, A.P. 18-1027, Col. Escandón, Delegación Miguel Hidalgo, C.P. 11801, México D.F., Mexico.
Department of Chemical & Materials Engineering, New Mexico State University, P.O. Box 30001, MSC 3805, Las Cruces, NM 88003, USA.
J Hazard Mater. 2016 Jan 25;302:341-350. doi: 10.1016/j.jhazmat.2015.09.070. Epub 2015 Oct 9.
The sorption behavior of the Ba(2+)-like (226)Ra(2+) in the presence of H2AsO4(-)/HAsO4(2-) and F(-) from aqueous media using Ce-Fe-modified zeolite-rich tuff was investigated in this work. The Na-modified zeolite-rich tuff was also considered for comparison purposes. The zeolite-rich tuff collected from Wyoming (US) was in contact with NaCl and CeCl3-FeCl3 solutions to obtain the Na- and Ce-Fe-modified zeolite-rich tuffs (ZUSNa and ZUSCeFe). These zeolites were characterized by scanning electron microscopy and X-ray diffraction. The BET-specific surface and the points of zero charge were determined as well as the content of Na, Ce and Fe by neutron activation analysis. The textural characteristics and the point of zero charge were changed by the presence of Ce and Fe species in the zeolitic network. A linear model described the Ba(2+)-like (226)Ra(2+) sorption isotherms and the distribution coefficients (Kd) varied with respect to the metallic species present in the zeolitic material. The As(V) oxianionic chemical species and F(-) affected this parameter when the Ba(2+)-like (226)Ra(2+)-As(V)-F(-) solutions were in contact with ZUSCeFe. The H2AsO4(-)/HAsO4(2-) and F(-) were adsorbed by ZUSCeFe in the same amount, independent of the concentration of Ba(2+)-like (226)Ra(2+) in the initial solution.
本工作研究了 Ce-Fe 改性沸石富型凝灰岩在含有 H2AsO4(-)/HAsO4(2-)和 F(-)的水溶液中对 Ba(2+)-like (226)Ra(2+)的吸附行为。还考虑了 Na 改性沸石富型凝灰岩作为比较。从怀俄明州(美国)采集的沸石富型凝灰岩与 NaCl 和 CeCl3-FeCl3 溶液接触,以获得 Na 和 Ce-Fe 改性沸石富型凝灰岩(ZUSNa 和 ZUSCeFe)。这些沸石通过扫描电子显微镜和 X 射线衍射进行了表征。通过中子活化分析确定了 BET 比表面积和零电荷点以及 Na、Ce 和 Fe 的含量。Ce 和 Fe 物种的存在改变了沸石网络的结构特征和零电荷点。线性模型描述了 Ba(2+)-like (226)Ra(2+)的吸附等温线,分配系数(Kd)随沸石材料中存在的金属物种而变化。当 Ba(2+)-like (226)Ra(2+)-As(V)-F(-)溶液与 ZUSCeFe 接触时,As(V) 含氧阴离子化学物质和 F(-)会影响该参数。H2AsO4(-)/HAsO4(2-)和 F(-)被 ZUSCeFe 等量吸附,与初始溶液中 Ba(2+)-like (226)Ra(2+)的浓度无关。