Unité de Recherche de Chimie Appliquée et Environnement, Faculté des Sciences de Monastir, Tunisia.
J Hazard Mater. 2009 Dec 30;172(2-3):1579-90. doi: 10.1016/j.jhazmat.2009.08.030. Epub 2009 Aug 15.
The present work describes the preparation of new chelating materials derived from Posidonia for adsorption of heavy metal ions and dye in aqueous solution. The first part of this report deals with the chemical modification of Posidonia with succinic anhydride. Thus, we have obtained materials with various succinyl groups contents (from 29.8 to 39.2%). The obtained materials were characterized by infrared and CP/MAS (13)C-RMN spectroscopy. The rate of succinyl content of the modified Posidonia was determined by saponification. The second part is devoted to the evaluation of the adsorption capacity of metal ions such as Pb(2+) and dye such as direct red 75 (DR75) for raw and modified Posidonia materials. Two possible ways for the adsorption of these pollutants are studied: adsorption of each pollutant alone onto these supports, and cumulative adsorption of both metal ions and dye on the same supports. In the last case, the pollutant is adsorbed successively from two different solutions. The effects of pollutants concentration, support dose, pH, contact time and temperature on adsorption of each pollutant were evaluated. The results showed that the raw and modified Posidonia show a high capacity for Pb(2+) adsorption. The capacity of modified Posidonia saturated with Pb(2+) to adsorb DR75 was found 147.12 mg g(-1). While the adsorption capacity of the nonsaturated modified Posidonia was equal to 81.63 mg g(-1). The pseudo-second-order model was the best to represent adsorption kinetics of DR75. The pseudo-first-order model would be better for fitting the adsorption kinetic process of Pb(2+) onto raw and modified Posidonia. The adsorption isotherms of Pb(2+) could be described by the Jossens equation model. Any of the tested models can describe the adsorption of DR75 onto the studied materials. These results confirm that the adsorption of DR75 from aqueous solution was multilayer.
本工作描述了从波西多尼亚中制备新螯合材料，以用于吸附水溶液中的重金属离子和染料。本报告的第一部分涉及用琥珀酸酐对波西多尼亚进行化学修饰。因此，我们获得了具有不同琥珀酰基含量（29.8%至 39.2%）的材料。通过红外光谱和 CP/MAS（13）C-RMN 光谱对所得材料进行了表征。通过皂化法确定了改性波西多尼亚的琥珀酰基含量。第二部分致力于评估原始和改性波西多尼亚材料对金属离子（如 Pb(2+)）和染料（如直接红 75（DR75））的吸附能力。研究了两种吸附这些污染物的可能途径：单独将每种污染物吸附到这些载体上，以及在相同的载体上同时吸附两种金属离子和染料。在后一种情况下，污染物是从两种不同的溶液中连续吸附的。评估了污染物浓度、载体剂量、pH 值、接触时间和温度对每种污染物吸附的影响。结果表明，原始和改性波西多尼亚对 Pb(2+)吸附具有很高的容量。用 Pb(2+)饱和的改性波西多尼亚吸附 DR75 的容量为 147.12mg/g。而未饱和的改性波西多尼亚的吸附容量为 81.63mg/g。拟二级动力学模型最适合表示 DR75 的吸附动力学。拟一级动力学模型更适合拟合 Pb(2+)在原始和改性波西多尼亚上的吸附动力学过程。Pb(2+)的吸附等温线可以用 Jossens 方程模型来描述。测试的任何模型都可以描述 DR75 在研究材料上的吸附。这些结果证实，DR75 从水溶液中的吸附是多层的。
