Department of Hydrotechnics, Faculty Civil Engineering, University of Prishtina, 10000 Prishtina, Kosovo.
Department of Chemistry, Faculty of Natural and Mathematics Science, University of Prishtina, 10000 Prishtina, Kosovo.
Molecules. 2022 Mar 12;27(6):1856. doi: 10.3390/molecules27061856.
The interaction of methylene blue (MB) dye with natural coal (collected from coal landfills of the Kosovo Energy Corporation) in aqueous solutions was studied using adsorption, kinetics, and thermodynamic data, and Monte Carlo (MC) calculations. In a batch procedure, the effects of contact duration, initial MB concentration, pH, and solution temperature on the adsorption process were examined. The Langmuir, Freundlich, Temkin, and Dubinin-Radushkevich (D-R) isotherms were used to examine the equilibrium adsorption data. The equilibrium data fit well to the Freundlich and Langmuir adsorption isotherm models; however, the Freundlich model suited the adsorption data to a slightly better extent than the Langmuir model. The kinetics experimental data was fitted using pseudo-first-order, first-order, pseudo-second-order, second-order, Elvoich equation, and diffusion models. The pseudo-second-order rate model manifested a superlative fit to the experimental data, while the adsorption of MB onto coal is regulated by both liquid film and intraparticle diffusions at the same time. Thermodynamic parameters, such as Gibbs free energy (Δ), enthalpy (Δ), and entropy (Δ) were calculated. The adsorption of MB was confirmed to be spontaneous and endothermic. The theoretical results were in agreement with the experimental ones.
采用吸附、动力学和热力学数据以及蒙特卡罗（MC）计算研究了亚甲蓝（MB）染料与天然煤（取自科索沃能源公司的煤填埋场）在水溶液中的相互作用。在分批程序中，考察了接触时间、初始 MB 浓度、pH 和溶液温度对吸附过程的影响。采用 Langmuir、Freundlich、Temkin 和 Dubinin-Radushkevich（D-R）等温线来研究平衡吸附数据。平衡吸附数据很好地符合 Freundlich 和 Langmuir 吸附等温线模型；然而，Freundlich 模型比 Langmuir 模型更适合吸附数据。通过拟一级、一级、拟二级、二级、Elvoich 方程和扩散模型拟合动力学实验数据。拟二级速率模型与实验数据拟合得非常好，而 MB 对煤的吸附同时受液膜和颗粒内扩散的控制。计算了热力学参数，如吉布斯自由能（Δ）、焓（Δ）和熵（Δ）。MB 的吸附被证实是自发的和吸热的。理论结果与实验结果一致。
