Ayach Jana, Duma Luminita, Badran Adnan, Hijazi Akram, Martinez Agathe, Bechelany Mikhael, Baydoun Elias, Hamad Hussein
Research Platform for Environmental Science (PRASE), Doctoral School of Science and Technology, Lebanese University, Beirut P.O. Box 657314, Lebanon.
CNRS, ICMR UMR 7312, University of Reims Champagne-Ardenne, 51687 Reims, France.
Materials (Basel). 2024 Jun 3;17(11):2724. doi: 10.3390/ma17112724.
Driven by concerns over polluted industrial wastewater, particularly heavy metals and dyes, this study explores biosorption using chemically cross-link chitosan derivatives as a sustainable and cost-effective depollution method. Chitosan cross-linking employs either water-soluble polymers and agents like glutaraldehyde or copolymerization of hydrophilic monomers with a cross-linker. Chemical cross-linking of polymers has emerged as a promising approach to enhance the wet-strength properties of materials. The chitosan thus extracted, as powder or gel, was used to adsorb heavy metals (lead (Pb) and copper (Cu)) and dyes (methylene blue (MB) and crystal violet (CV)). Extensive analysis of the physicochemical properties of both the powder and hydrogel adsorbents was conducted using a range of analytical techniques, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET), and scanning electron microscopy (SEM), as well as H and C nuclear magnetic resonance (NMR). To gain a comprehensive understanding of the sorption process, the effect of contact time, pH, concentration, and temperature was investigated. The adsorption capacity of chitosan powder for Cu(II), Pb(II), methylene blue (MB), and crystal violet (CV) was subsequently determined as follows: 99, 75, 98, and 80%, respectively. In addition, the adsorption capacity of chitosan hydrogel for Cu(II), Pb(II), MB, and CV was as follows: 85, 95, 85, and 98%, respectively. The experimental data obtained were analyzed using the Langmuir, Freundlich, and Dubinin-Radushkevich isotherm models. The isotherm study revealed that the adsorption equilibrium is well fitted to the Freundlich isotherm (R = 0.998), and the sorption capacity of both chitosan powder and hydrogel was found to be exceptionally high (approximately 98%) with the adsorbent favoring multilayer adsorption. Besides, Dubinin has given an indication that the sorption process was dominated by Van der Waals physical forces at all studied temperatures.
受对污染工业废水（尤其是重金属和染料）的担忧驱动，本研究探索了使用化学交联壳聚糖衍生物作为一种可持续且经济高效的去污染方法的生物吸附作用。壳聚糖交联采用水溶性聚合物和诸如戊二醛之类的试剂，或者亲水性单体与交联剂的共聚反应。聚合物的化学交联已成为增强材料湿强度性能的一种有前景的方法。如此提取的壳聚糖，以粉末或凝胶形式，被用于吸附重金属（铅（Pb）和铜（Cu））以及染料（亚甲基蓝（MB）和结晶紫（CV））。使用一系列分析技术，包括傅里叶变换红外光谱（FTIR）、X射线衍射（XRD）、布鲁诺尔-埃米特-泰勒（BET）和扫描电子显微镜（SEM）以及氢和碳核磁共振（NMR），对粉末和水凝胶吸附剂的物理化学性质进行了广泛分析。为全面了解吸附过程，研究了接触时间、pH值、浓度和温度的影响。随后确定壳聚糖粉末对铜（II）、铅（II）、亚甲基蓝（MB）和结晶紫（CV）的吸附容量分别如下：99%、75%、98%和80%。此外，壳聚糖水凝胶对铜（II）、铅（II）、MB和CV的吸附容量分别如下：85%、95%、85%和98%。使用朗缪尔、弗伦德利希和杜比宁-拉杜舍维奇等温线模型对获得的实验数据进行了分析。等温线研究表明吸附平衡很好地符合弗伦德利希等温线（R = 0.998），并且发现壳聚糖粉末和水凝胶的吸附容量都非常高（约98%），吸附剂有利于多层吸附。此外，杜比宁表明在所有研究温度下吸附过程均由范德华物理力主导。
