Comparative study of Cu2+ adsorption on a zeolite, a clay and a diatomite from Serbia
Comparative study of Cu2+ adsorption on a zeolite, a clay and a diatomite from Serbia
复制标题
DOI：
10.1016/j.clay.2008.07.009
复制
发表时间：
2009
影响因子：
5.6
通讯作者：
M. Šljivić;I. Smičiklas;S. Pejanović;I. Plećaš
中科院分区：
文献类型：
--
作者：
M. Šljivić;I. Smičiklas;S. Pejanović;I. Plećaš
研究了来自塞尔维亚的沸石、粘土和硅藻土在不同 pH 值下对含水 Cu2+ 离子的吸附情况。吸附剂的相组成、比表面积和零电荷点进行了表征。由于 Cu(OH)2 的沉淀，无论吸附剂类型和金属浓度如何，从溶液中去除的 Cu2+ 量随着初始 pH 值的增加而增加，在 pH>7 时几乎达到 100%。相对恒定的最终 pH 值和在初始 pH 范围 4-6 内观察到的 Cu2+ 吸收不太显着的增加表明了所研究的吸附材料的缓冲特性的作用。最大吸附容量按沸石 (0.128 mmol/g) > 粘土 (0.096 mmol/g) > 硅藻土 (0.047 mmol/g) 的顺序降低。 Langmuir 方程最适合数据拟合。 Cu2+在酸性介质中解吸的比例随着沸石和粘土先前吸附量的增加而减少，而硅藻土则相反。可交换阳离子和质子的离子交换被认为是主要的吸附机制，其中后者在硅藻土的去除机制中最为明显。考虑到低成本、本地可获得性和环保材料，沸石在环境和健康保护应用方面表现出最大的潜力。
The adsorption of a zeolite, clay and diatomite from Serbia toward aqueous Cu2+ions was studied, at different pH. The adsorbents were characterized with respect to phase composition, specific surface area and point of zero charge. The amounts of Cu2+removed from the solution, increased with increasing initial pH, reaching nearly 100% at pH>7, regardless of the adsorbent type and metal concentration, due to precipitation of Cu(OH)2. Relatively constant final pH values and less significant increase of Cu2+uptake observed in the initial pH range 4–6 have pointed out the role of buffering properties of investigated adsorbent materials. The maximum adsorption capacities decreased in the order zeolite (0.128 mmol/g)>clay (0.096 mmol/g)>diatomite (0.047 mmol/g). The Langmuir equation was most suitable for data fitting. The proportion of Cu2+desorbed in acidic media decreased with the increase of previously adsorbed amounts by zeolite and clay, while the opposite was true for diatomite. Ion exchange of exchangeable cations and protons were identified as main adsorption mechanisms, with latter being most apparent in the removal mechanism of diatomite. Considering low-cost, local availability and environmentally friendly materials, zeolite exhibited highest potential for environmental and health protection applications.