Masoumi Hadiseh, Ghaemi Ahad
School of Chemical, Petroleum and Gas Engineering, Iran University of Science and Technology, Tehran, Iran.
Sci Rep. 2024 Feb 27;14(1):4817. doi: 10.1038/s41598-024-54430-0.
In this research, the waste polycarbonate was hypercrosslinked during the Friedel-Crafts reaction to eliminate metallic ions from the wastewater solution. The experiments for inspecting the adsorption behavior of lead and cadmium ions were conducted at the initial concentration of 20-100 mg/L, contact time of 10-80 min, temperature of 20-80 °C, and pH of 6-11. The isotherm, kinetic, and thermodynamic models have been used to explain the behavior of the metal ions removal process. The correlation coefficient and adsorption capacity of the kinetic model for cadmium ion have obtained 0.995 and 160.183 mg/g, respectively, and the correlation coefficient and adsorption capacity of the kinetic model for lead ion has obtained 0.998 and 160.53 mg/g, respectively, which declared that the cascade was not monolayer. The correlation coefficient of the Freundlich is calculated at 0.995 and 0.998 for Cd and Pb, respectively, indicating the resin plane was not homogenized. The n constant for cadmium and lead ions has been calculated at 2.060 and 1.836, respectively, confirming that the resin is not homogenized, and the process has performed well. Afterward, the values of enthalpy and Gibbs free energy changes were obtained at - 7.68 kJ/mol and - 0.0231 kJ/mol.K for lead ions, respectively, which implies the exothermic and spontaneous state of the process. The values of enthalpy and Gibbs free energy changes have been obtained at - 6.62 kJ/mol and - 0.0204 kJ/mol.K for cadmium ions, respectively, which implies the exothermic and spontaneous nature of the adsorption. Also, the optimal empirical conditions for lead and cadmium ions have been found at a time of 60 min, temperature of 20 °C, initial concentration of 100 mg/L, and pH of 10. At a time of 45 min, the diffusion coefficient and mass transfer coefficient for lead ions have been calculated at 0.1269 × 10 m/s and 0.2028 × 10 m/s, respectively. In addition, at a time of 45 min, the diffusion coefficient and mass transfer coefficient for cadmium ions have been calculated at 0.1463 × 10 m/s and 0.1054 × 10 m/s, respectively. Moreover, the mechanism study explains that the C-O-C and C-H in the aromatic groups have a crucial aspect in the bond formation among metallic ions and resin.
在本研究中，废聚碳酸酯在傅克反应过程中进行了超交联，以去除废水溶液中的金属离子。在初始浓度为20 - 100 mg/L、接触时间为10 - 80分钟、温度为20 - 80°C以及pH值为6 - 11的条件下，进行了铅和镉离子吸附行为的实验。采用等温线、动力学和热力学模型来解释金属离子去除过程的行为。镉离子动力学模型的相关系数和吸附容量分别为0.995和160.183 mg/g，铅离子动力学模型的相关系数和吸附容量分别为0.998和160.53 mg/g，这表明该吸附过程不是单层吸附。Freundlich模型中镉和铅的相关系数分别计算为0.995和0.998，表明树脂表面不均匀。镉和铅离子的n常数分别计算为2.060和1.836，证实树脂不均匀，但该过程表现良好。之后，铅离子的焓变和吉布斯自由能变化值分别为−7.68 kJ/mol和−0.0231 kJ/mol·K，这意味着该过程是放热且自发的。镉离子的焓变和吉布斯自由能变化值分别为−6.62 kJ/mol和−0.0204 kJ/mol·K，这意味着吸附过程具有放热和自发的性质。此外，还发现铅和镉离子的最佳实验条件为时间60分钟、温度20°C、初始浓度100 mg/L以及pH值10。在45分钟时，铅离子的扩散系数和传质系数分别计算为0.1269×10⁻⁹ m²/s和0.2028×10⁻⁹ m²/s。此外，在45分钟时，镉离子的扩散系数和传质系数分别计算为0.1463×10⁻⁹ m²/s和0.1054×10⁻⁹ m²/s。此外，机理研究表明，芳香族基团中的C - O - C和C - H在金属离子与树脂之间的键形成中起着关键作用。
