Wasilewska Małgorzata, Derylo-Marczewska Anna, Marczewski Adam W
Department of Physical Chemistry, Institute of Chemical Sciences, Maria Curie-Sklodowska University, Maria Curie-Sklodowska Sq. 3, 20-031 Lublin, Poland.
Molecules. 2024 Apr 28;29(9):2038. doi: 10.3390/molecules29092038.
This work presents a comprehensive analysis of the adsorption of selected aromatic organic compounds on activated carbons. Both the equilibrium and kinetics of adsorption were studied using UV-Vis spectrophotometry. The influence of a number of factors: pH, contact time, presence of an accompanying substance, adsorbate concentration, as well as the mass and size of adsorbent grains, on the adsorption process from aqueous solutions was investigated. Phenol, 2-nitrophenol, 3-nitrophenol, 4-nitrophenol and methylene blue (as an accompanying substance) were selected as adsorbates. GAC 1240W and RIAA activated carbons were used as adsorbents. The equilibrium data were analyzed using the generalized Langmuir isotherm equation (R = 0.912-0.996). Adsorption rate data were fitted using a multi-exponential kinetic equation (1 - R = (1.0 × 10)-(8.2 × 10)). As an additional parameter, the half-time was also used to present the influence of selected factors on the adsorption kinetics. An increase in the amount of adsorption was demonstrated with increasing contact time as well as with decreasing solution pH and adsorbent grain size. For selected systems, an increase in the adsorption rate was observed with increasing adsorbate concentration, adsorbent mass and at lower pH values. In some cases, the presence of an accompanying substance also resulted in an increase in adsorption kinetics. In the tested experimental systems, optimal conditions for adsorption were established (T = 298 K, pH = 2, contact time: 7 days, grain diameter: >0.5 mm and the ratio of the mass of the adsorbent to the volume of the adsorbate solution: 1 g/L). Additionally, the acid-base properties (potentiometric titration), morphology (SEM) and structure (TEM) of the used adsorbents were also examined.
这项工作对选定的芳香族有机化合物在活性炭上的吸附进行了全面分析。使用紫外可见分光光度法研究了吸附的平衡和动力学。研究了许多因素对水溶液吸附过程的影响，这些因素包括pH值、接触时间、伴随物质的存在、吸附质浓度以及吸附剂颗粒的质量和尺寸。选择苯酚、2-硝基苯酚、3-硝基苯酚、4-硝基苯酚和亚甲基蓝（作为伴随物质）作为吸附质。使用GAC 1240W和RIAA活性炭作为吸附剂。使用广义朗缪尔等温线方程（R = 0.912 - 0.996）分析平衡数据。使用多指数动力学方程（1 - R = (1.0 × 10)-(8.2 × 10)）拟合吸附速率数据。作为一个附加参数，半衰期也被用来表示选定因素对吸附动力学的影响。随着接触时间的增加以及溶液pH值和吸附剂颗粒尺寸的减小，吸附量增加。对于选定的体系，随着吸附质浓度、吸附剂质量的增加以及在较低pH值下，观察到吸附速率增加。在某些情况下，伴随物质的存在也导致吸附动力学增加。在测试的实验体系中，确定了吸附的最佳条件（T = 298 K，pH = 2，接触时间：7天，粒径：>0.5 mm，吸附剂质量与吸附质溶液体积之比：1 g/L）。此外，还研究了所用吸附剂的酸碱性质（电位滴定）、形态（扫描电子显微镜）和结构（透射电子显微镜）。
