Extra-framework cation release from heulandite-type rich tuffs on exchange with NH(4)(+).
Extra-framework cation release from heulandite-type rich tuffs on exchange with NH(4)(+).
复制标题
富含片沸石型凝灰岩与 NH(4)( ) 交换时释放骨架外阳离子。
DOI：
10.1016/j.jenvman.2011.01.013
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发表时间：
2011
影响因子：
8.7
通讯作者：
A. Filippidis
中科院分区：
文献类型：
--
作者：
N. Kantiranis;K. Sikalidis;A. Godelitsas;C. Squires;G. Papastergios;A. Filippidis
希腊富含片沸石的凝灰岩样品（片沸石III型，91wt. %，云母4重量%，长石5wt. %，CEC 2.22meq/g）在与乙酸铵交换后使用原子吸收光谱法（AAS）进行分析。每种阳离子的动力学曲线进行了研究，在720小时的总接触时间与采样频繁的间隔。用X射线粉末衍射、扫描电镜能谱和原子吸收光谱对材料进行了表征。采用乙酸铵饱和法测定吸附能力。发现Ca2+呈现出意想不到的骨架外释放和令人惊讶的高交换度（90%）。Mg的交换（57%）也值得注意，而K+的行为显示出预期的快速初始释放。Na+的行为必须类似。然而，其在沸石材料中的较低浓度使其总体意义稍微最小化。另一方面，与碱金属离子的释放相比，Ca 2+和Mg 2+的释放在动力学上慢得多，并且这种现象表明直到最终平衡需要不同的交换能量。
The outgoing cations of Greek heulandite-rich tuff samples (heulandite type-III, 91wt.%, mica 4wt.%, feldspar 5wt. %, CEC 2.22meq/g) were analysed upon exchange with ammonium acetate using atomic absorption spectrometry (AAS). The kinetic curves of each cation were investigated over a total time of contact of 720h with sampling at frequent intervals. The materials were examined by powder X-ray diffraction, SEM-EDS, and AAS. The sorption ability was measured using the ammonium acetate saturation method. It was found that Ca2+presents an unexpected extra-framework release and a surprisingly high degree of exchange (90%). The exchange of Mg (57%) is also worthy of note whereas the behavior of K+showed an expected rapid initial release. The behavior of Na+must be similar. However, its lower concentration in the zeolitic material minimizes its overall significance somewhat. On the other hand, Ca2+and Mg2+release is kinetically much slower, compared to that of alkali metal ions, and this phenomenon indicates that different exchange energies are needed till final equilibrium.