Gaur Bharti, Mittal Jyoti, Hassan Hadi, Mittal Alok, Baker Richard T
Department of Chemistry, Maulana Azad National Institute of Technology, Bhopal 462 003, India.
School of Chemistry, University of St. Andrews, St. Andrews, Fife KY16 9ST, UK.
Molecules. 2024 Aug 29;29(17):4100. doi: 10.3390/molecules29174100.
A nanostructured material, ordered mesoporous carbon (OMC), was synthesised in metal- and halide-free form and its use for the sequestration of crystal violet, a hazardous triphenylmethane dye, is reported for the first time. The OMC material is characterised using scanning transmission electron microscopy with energy-dispersive spectroscopy for chemical analysis, by Fourier-transform infrared spectroscopy, and by nitrogen gas physisorption. The ideal conditions for the uptake of crystal violet dye were determined in batch experiments covering the standard parameters: pH, concentration, contact time, and adsorbent dosage. Experimental data are validated by applying Langmuir, Freundlich, Dubinin-Radushkevich, and Temkin isotherms. The thermodynamic parameters, ΔH°, ΔG°, and ΔS°, are calculated and it has been found that the adsorption process is spontaneous and endothermic with increasing disorder. An in-depth analysis of the kinetics of the adsorption process, order of the reaction and corresponding values of the rate constants was performed. The adsorption of crystal violet over OMC has been found to follow pseudo-second-order kinetics through a film diffusion process at all temperatures studied. Continuous flow column operations were performed using fixed bed adsorption. Parameters including percentage saturation of the OMC bed are evaluated. The exhausted column was regenerated through a desorption process and column efficiency was determined.
合成了一种无金属和无卤化物形式的纳米结构材料——有序介孔碳（OMC），并首次报道了其用于螯合有害三苯甲烷染料结晶紫的应用。使用配备能谱进行化学分析的扫描透射电子显微镜、傅里叶变换红外光谱和氮气物理吸附对OMC材料进行了表征。在涵盖标准参数（pH、浓度、接触时间和吸附剂用量）的批量实验中确定了摄取结晶紫染料的理想条件。通过应用朗缪尔等温线、弗伦德里希等温线、杜比宁-拉杜什凯维奇等温线和坦金等温线对实验数据进行了验证。计算了热力学参数ΔH°、ΔG°和ΔS°，发现吸附过程是自发的且随着无序度增加是吸热的。对吸附过程的动力学、反应级数和速率常数的相应值进行了深入分析。发现在所有研究温度下，结晶紫在OMC上的吸附通过膜扩散过程遵循准二级动力学。使用固定床吸附进行连续流柱操作。评估了包括OMC床饱和百分比在内的参数。通过解吸过程对耗尽的柱进行再生，并确定柱效率。
