A model for the adsorption of single metal ion solutes in aqueous solution onto activated carbon produced from pecan shells
A model for the adsorption of single metal ion solutes in aqueous solution onto activated carbon produced from pecan shells
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DOI：
10.1016/s0008-6223(02)00037-4
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发表时间：
2002-01-01
期刊：
影响因子：
10.9
通讯作者：
Rockstraw, DA
中科院分区：
文献类型：
--
作者：
Dastgheib, SA;Rockstraw, DA
得到了由山核桃壳制成的活性炭在25℃和pH约为3时对多种金属离子溶质的吸附等温线。结果表明，滑移方程和Freundlich方程可以很好地解释实验数据。研究了金属离子吸附与金属离子电负性溶质参数和金属氢氧化物第一稳定常数的关系。在研究的大多数金属离子的情况下，较高的电负性和稳定性常数对应于较高的金属离子在活性炭上的吸附水平。利用选定的金属离子参数，建立了一种预测Freundlich方程常数的关联关系，从而可以预测恒定ph下的吸附等温线。所建立的关联关系给出的结果与实验数据有可接受的偏差。提出了在不同条件下（温度、pH、碳类型和剂量）获得相似相关性的方法。计算了在所研究的金属离子在一定浓度范围内吸附的等效金属离子与释放的质子的比率。在大多数情况下，特别是在低浓度下，这个比率接近于1，证实了一个质子与一个等效金属离子的离子交换是主要的反应机制。(C) 2002 Elsevier Science Ltd.版权所有。
Adsorption isotherms for activated carbon made from pecan shells have been obtained at 25 degreesC and an approximate pH of 3 for a number of metal ion solutes. It was found that the Slips and Freundlich equations were satisfactory for explaining the experimental data. The correlation of metal ion adsorption with the solute parameters of metal ion electronegativity and first stability constant of the metal hydroxide was investigated. In the case of most of the metal ions studied, higher electronegativities and stability constants corresponded to the higher adsorption levels of metal ions onto the activated carbon. A correlation was developed that predicts the constants of the Freundlich equation from the selected parameters of the metal ions, and thus can predict the adsorption isotherms at constant pH. The developed correlation gives results with acceptable deviations from experimental data. A procedure is proposed for obtaining similar correlations for different conditions (temperature, pH, carbon type and dosage). The ratio of equivalent metal ions adsorbed to protons released is calculated for the studied metal ions over a range of concentrations. In most cases, particularly at low concentrations, this ratio is close to one, confirming that ion exchange of one proton with one equivalent metal ion is the dominant reaction mechanism. (C) 2002 Elsevier Science Ltd. All rights reserved.