Mobarak Mohamed, Ali Rabea A M, Seliem Moaaz K
Physics Department, Faculty of Science, Beni-Suef University, Egypt.
Geology Department, Faculty of Science, Beni-Suef University, 62511, Egypt.
Int J Biol Macromol. 2021 Sep 1;186:750-758. doi: 10.1016/j.ijbiomac.2021.07.089. Epub 2021 Jul 16.
Chitosan was impregnated into porous activated coal to produce a multifunctional chitosan/activated coal (Cs/Ac) composite. The resulted Cs/Ac was characterized and utilized as a cost-effective adsorbent for Mn(VII) at altered temperatures (i.e., 25, 35, and 45 °C). The adsorption results were fitted to classical as well as advanced statistical physics models. The Freundlich equation described well the achieved experimental data at all temperatures. Enhancing the Langmuir adsorption capacity from 203.26 to 224.03 mg/g with temperature indicated that Mn(VII) adsorption was an endothermic process. Steric, energetic and thermodynamics data of the double layer model with two energy sites (i.e., the best fit statistical model) were completely interpreted. The number of Mn(VII) per adsorption site (n) was between 0.76 and 0.92 suggested the presence of multi-docking and multi-interactions mechanisms. The active sites density (N) of the Cs/Ac decreased with improving temperature. Energetically, Mn(VII) uptake by Cs/Ac was governed by physical interactions (i.e., adsorption energy <40 kJ/mol). Macroscopically, the interaction between Mn(VII) and Cs/Ac was spontaneous. Overall, modification of the Ac by the used marine biomass (Cs) produced a promising Mn(VII) adsorbent and also, the application of physical analysis offered a deep interpretation for the adsorption mechanism.
将壳聚糖浸渍到多孔活性炭中，制备出多功能壳聚糖/活性炭（Cs/Ac）复合材料。对所得的Cs/Ac进行了表征，并将其用作在不同温度（即25、35和45℃）下吸附Mn(VII)的经济高效吸附剂。吸附结果与经典以及先进的统计物理模型进行了拟合。Freundlich方程很好地描述了所有温度下获得的实验数据。随着温度升高，Langmuir吸附容量从203.26 mg/g提高到224.03 mg/g，这表明Mn(VII)吸附是一个吸热过程。对具有两个能量位点的双层模型（即最佳拟合统计模型）的空间、能量和热力学数据进行了全面解读。每个吸附位点的Mn(VII)数量（n）在0.76至0.92之间，表明存在多对接和多相互作用机制。Cs/Ac的活性位点密度（N）随着温度升高而降低。从能量角度来看，Cs/Ac对Mn(VII)的吸收受物理相互作用控制（即吸附能<40 kJ/mol）。从宏观角度来看，Mn(VII)与Cs/Ac之间的相互作用是自发的。总体而言，用所用海洋生物质（Cs）对Ac进行改性制备出了一种有前景的Mn(VII)吸附剂，而且，物理分析的应用为吸附机制提供了深入解读。
