Karthik Rathinam, Meenakshi Sankaran
Department of Chemistry, Gandhigram Rural Institute-Deemed University, Gandhigram, Dindigul 624 302, Tamil Nadu, India.
Department of Chemistry, Gandhigram Rural Institute-Deemed University, Gandhigram, Dindigul 624 302, Tamil Nadu, India.
Int J Biol Macromol. 2014 Jun;67:210-9. doi: 10.1016/j.ijbiomac.2014.03.035. Epub 2014 Mar 27.
In the present investigation, the removal of Cr(VI) ions from aqueous solution using cross linked-chitosan-grafted-polyaniline composite (CCGP) was compared with that of chitosan-grafted-polyaniline (CGP) composite. The composites were characterized using FTIR, SEM-EDX, XRD, DSC, and TGA techniques. Batch equilibrium method was used for the optimization of various equilibrium parameters such as pH, contact time, dosage and initial Cr(VI) ion concentration. The removal efficiency by CCGP composite was found to be higher compared to CGP composite in all the studied conditions. The adsorption process was well described by Freundlich isotherm model for both the composites. The maximum adsorption capacity of CGP and CCGP composite for Cr(VI) ions was 165.6mg/g and 179.2mg/g at 303K. Thermodynamic parameters for the adsorption system were calculated and concluded that the nature of sorption was spontaneous and endothermic in nature. The Cr(VI) adsorption kinetic process was well described by pseudo-second-order kinetic model and the sorption process was being controlled by intraparticle diffusion pattern. Desorption and regeneration experiments of CGP and CCGP composites were performed and reused for more than two consecutive cycles.
在本研究中，将使用交联壳聚糖接枝聚苯胺复合材料（CCGP）从水溶液中去除六价铬离子的效果与壳聚糖接枝聚苯胺（CGP）复合材料进行了比较。采用傅里叶变换红外光谱（FTIR）、扫描电子显微镜-能谱仪（SEM-EDX）、X射线衍射（XRD）、差示扫描量热法（DSC）和热重分析法（TGA）对复合材料进行了表征。采用间歇平衡法对pH值、接触时间、用量和初始六价铬离子浓度等各种平衡参数进行了优化。发现在所有研究条件下，CCGP复合材料的去除效率均高于CGP复合材料。两种复合材料的吸附过程均能很好地用弗伦德利希等温线模型描述。在303K时，CGP和CCGP复合材料对六价铬离子的最大吸附容量分别为165.6mg/g和179.2mg/g。计算了吸附系统的热力学参数，得出吸附性质为自发且吸热的结论。六价铬的吸附动力学过程能用准二级动力学模型很好地描述，吸附过程受颗粒内扩散模式控制。对CGP和CCGP复合材料进行了解吸和再生实验，并连续重复使用了两个以上周期。
