使用负载La(III)的羧化壳聚糖珠增强氟吸附
Enhanced fluoride sorption using La(III) incorporated carboxylated chitosan beads.
作者信息
Viswanathan Natrayasamy, Meenakshi S
机构信息
Department of Chemistry, Gandhigram Rural University, Gandhigram 624 302, Tamilnadu, India.
出版信息
J Colloid Interface Sci. 2008 Jun 15;322(2):375-83. doi: 10.1016/j.jcis.2008.03.007. Epub 2008 Mar 15.
The carboxylated chitosan beads (CCB), which have a defluoridation capacity (DC) of 1385 mg F(-)/kg, have been further chemically modified by incorporating La(3+) ion (La-CCB) and its DC was found to be 4711 mg F(-)/kg whereas the raw chitosan beads (CB) possess only 52 mg F(-)/kg. The fluoride removal by La-CCB is governed by both adsorption and complexation mechanism. The functional groups present in beads were identified by FTIR analysis. The surface condition and existence of fluoride on the beads was confirmed by SEM with EDAX analysis. The experimental data have been analyzed using Freundlich and Langmuir isotherm models. Thermodynamic parameters such as DeltaG(o), DeltaH(o) and DeltaS(o) were calculated to predict the nature of sorption. The kinetic studies were investigated with reaction-based and diffusion-based models. A field trial was carried out with fluoride water collected from a nearby fluoride-endemic village.
羧化壳聚糖珠（CCB）的除氟能力（DC）为1385 mg F(-)/kg，通过掺入La(3+)离子进一步进行化学改性得到La-CCB，其除氟能力为4711 mg F(-)/kg，而未改性的壳聚糖珠（CB）的除氟能力仅为52 mg F(-)/kg。La-CCB除氟受吸附和络合两种机制控制。通过傅里叶变换红外光谱（FTIR）分析确定了珠子中存在的官能团。通过扫描电子显微镜（SEM）和能谱分析（EDAX）确认了珠子的表面状况和氟的存在。使用弗伦德利希（Freundlich）和朗缪尔（Langmuir）等温线模型对实验数据进行了分析。计算了诸如标准吉布斯自由能变化（ΔG(o)）、标准焓变（ΔH(o)）和标准熵变（ΔS(o)）等热力学参数，以预测吸附的性质。采用基于反应和基于扩散的模型进行了动力学研究。对从附近氟中毒流行村庄采集的含氟水进行了现场试验。
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