Tataru-Farmus Ramona-Elena, Cimpoesu Ramona, Nica Iulia, Suteu Daniela
Department of Chemical Engineering, "Cristofor Simionescu" Faculty of Chemical Engineering and Environmental Protection, "Gheorghe Asachi" Technical University of Iasi, Prof. Dr. docent D. Mangeron Blvd., No. 73A, 700050 Iasi, Romania.
Department of Materials Science, Faculty of Materials Science and Engineering, "Gheorghe Asachi" Technical University of Iasi, Prof. Dr. docent D. Mangeron Blvd., No. 41, 700259 Iasi, Romania.
Polymers (Basel). 2023 Jan 31;15(3):715. doi: 10.3390/polym15030715.
Methylene Blue, a cationic dye, was retained from aqueous solutions using a novel biosorbent made of poly(vinyl alcohol) reticulated with tricarboxi-cellulose produced via TEMPO oxidation (OxC25). The study of the Methylene Blue biosorption process was performed with an emphasis on operational parameters that may have an impact on it (such as biosorbent concentration, pH of the aqueous media, and temperature). The current study focused on three areas: (i) the physic-chemical characterization of the biosorbent (scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX)); (ii) biosorption data modeling to determine the quantitative characteristic parameters employing three equilibrium isotherms (Langmuir, Freundlich, and Dubinin-Radushkevich-DR); and (iii) the study of temperature influence. The results of the study showed that the Langmuir model provided a good fit for the experimental data of biosorption, realizing a maximum capacity of 806.45 mg/g at 20 °C. The free energy of biosorption (E) evaluated by the DR equation was in the range of 6.48-10.86 KJ/mol. The values of the thermodynamic parameters indicated an endothermic process because the free Gibbs energy ranged from -9.286 KJ/mol to -2.208 KJ/mol and the enthalpy was approximately -71.686 KJ/mol. The results obtained encourage and motivate the further study of this biosorption process by focusing on its kinetic aspects, establishing the biosorption's controlled steps, identifying the mechanism responsible for the retention of textile dyes presented in moderate concentration in aqueous media, and studying the biosorption process in a dynamic regime with a view to applying it to real systems.
亚甲基蓝是一种阳离子染料，使用由经TEMPO氧化（OxC25）制备的三羧基纤维素网状化的聚乙烯醇制成的新型生物吸附剂，从水溶液中保留该染料。进行了亚甲基蓝生物吸附过程的研究，重点关注可能对其产生影响的操作参数（如生物吸附剂浓度、水介质的pH值和温度）。当前研究集中在三个方面：（i）生物吸附剂的物理化学表征（扫描电子显微镜（SEM）和能量色散X射线光谱（EDX））；（ii）生物吸附数据建模，以使用三种平衡等温线（朗缪尔等温线、弗伦德利希等温线和杜比宁-拉杜舍维奇等温线-DR等温线）确定定量特征参数；（iii）温度影响研究。研究结果表明，朗缪尔模型很好地拟合了生物吸附的实验数据，在20°C时实现了806.45mg/g的最大吸附量。通过DR方程评估的生物吸附自由能（E）在6.48-10.86kJ/mol范围内。热力学参数值表明该过程是吸热的，因为自由吉布斯能范围为-9.286kJ/mol至-2.208kJ/mol，焓约为-71.686kJ/mol。所得结果鼓励并推动通过关注其动力学方面、确定生物吸附的控制步骤、确定负责保留水介质中中等浓度纺织染料的机制以及研究动态条件下的生物吸附过程，以便将其应用于实际系统，来进一步研究这种生物吸附过程。
