Universidade Federal de Mato Grosso, UFMT, Centro de Recursos Minerais, 78060 900 Cuiabá, Mato Grosso, Brazil.
J Colloid Interface Sci. 2010 Jun 1;346(1):178-87. doi: 10.1016/j.jcis.2010.02.041. Epub 2010 Feb 21.
The original sepiolite clay mineral has been collected from Amazon region, Brazil. The compound 2-aminomethylpyridine (AMP) was anchored onto Amazon sepiolite surface by heterogeneous route. The natural (SPT) and modified (SPT(AMP)) sepiolite samples were characterized by elemental analysis, SEM, N(2) adsorption, and nuclear magnetic nuclei of (29)Si and (13)C. The well-defined peaks obtained in the (13)C NMR spectrum in the 0-160 ppm region confirmed the attachment of organic functional groups as pendant chains bonded into the porous clay. The ability of these materials to remove As(V) from aqueous solution was followed by a series of adsorption isotherms at room temperature and pH 4.0. The maximum number of moles adsorbed was determined to be 7.26×10(-2) and 11.70×10(-2) mmol g(-1) for SPT and SPT(AMP), respectively. In order to evaluate the clay samples as adsorbents in dynamic system, a glass column was fulfilled with clay samples (1.0 g) and it was fed with 2.0×10(-2) mmol dm(-3) As(V) at pH 4.0. The energetic effects caused by metal cations adsorption were determined through calorimetric titrations. Thermodynamics indicated the existence of favorable conditions for such As(V)-nitrogen interactions.
从巴西亚马逊地区采集了原始海泡石粘土矿物。通过非均相途径将 2-氨甲基吡啶（AMP）固定在亚马逊海泡石表面上。对天然（SPT）和改性（SPT（AMP））海泡石样品进行了元素分析、SEM、N2 吸附和（29）Si 和（13）C 的核磁共振分析。在 0-160 ppm 区域的（13）C NMR 谱中获得的特征峰证实了有机官能团作为侧链键合到多孔粘土中的附着。在室温下和 pH 4.0 下，通过一系列吸附等温线研究了这些材料从水溶液中去除 As(V)的能力。确定 SPT 和 SPT(AMP)的最大吸附摩尔数分别为 7.26×10(-2)和 11.70×10(-2)mmol g(-1)。为了评估粘土样品作为动态系统中的吸附剂，在玻璃柱中填充了 1.0 g 粘土样品，并以 pH 4.0 进料 2.0×10(-2)mmol dm(-3)As(V)。通过量热滴定法确定了金属阳离子吸附引起的能量效应。热力学表明存在有利于这种 As(V)-氮相互作用的有利条件。
