Viswanathan Natrayasamy, Sundaram C Sairam, Meenakshi S
Department of Chemistry, Gandhigram Rural University, Gandhigram 624302, Tamilnadu, India.
Colloids Surf B Biointerfaces. 2009 Jan 1;68(1):48-54. doi: 10.1016/j.colsurfb.2008.09.009. Epub 2008 Sep 19.
Carboxylated cross-linked chitosan beads (CCB) showed a significant defluoridation capacity (DC) of 1385 mgF(-)/kg than the raw chitosan beads (CB) which displayed only 52 mgF(-)/kg. Sorption experiments were performed by varying contact time, pH, presence of co-anions and temperature. The nature and morphology of the sorbent were discussed using FTIR and SEM with EDAX analysis. The stability of the beads in solution was explained in terms of swelling ratio of the beads. The fluoride uptake onto CCB obeys both Freundlich and Langmuir isotherms. Thermodynamic studies revealed that the nature of fluoride sorption is spontaneous and endothermic. Sorption kinetics is mainly controlled by pseudo-second-order and intraparticle diffusion models. 0.1M HCl was identified as the best eluent. The suitability of CCB at field conditions has been tested with field sample collected from a nearby fluoride-endemic area.
羧化交联壳聚糖珠（CCB）显示出显著的除氟能力（DC），为1385 mgF(-)/kg，而未处理的壳聚糖珠（CB）仅为52 mgF(-)/kg。通过改变接触时间、pH值、共存阴离子的存在和温度进行吸附实验。使用傅里叶变换红外光谱（FTIR）和扫描电子显微镜（SEM）以及能谱分析（EDAX）讨论了吸附剂的性质和形态。根据珠子的溶胀率解释了珠子在溶液中的稳定性。CCB对氟化物的吸附符合Freundlich和Langmuir等温线。热力学研究表明，氟化物吸附的性质是自发的且吸热的。吸附动力学主要由伪二级和颗粒内扩散模型控制。0.1M盐酸被确定为最佳洗脱剂。已使用从附近氟病区采集的现场样品测试了CCB在现场条件下的适用性。
