Department of Organic and Inorganic Chemistry, Faculty of Science, University of Extremadura, 06006, Badajoz, Spain.
Environ Sci Pollut Res Int. 2021 May;28(19):24342-24354. doi: 10.1007/s11356-020-08428-6. Epub 2020 Mar 24.
This study deals with the preparation of activated carbon (AC) from poly(ethylene terephthalate) (PET) waste and with the physicochemical characterization of AC and its use as adsorbent of bisphenol A (BPA) in aqueous solution. AC was prepared by chemical activation with KOH and by physical activation in steam. The activation with KOH was carried out by impregnation first of PET by wet and dry routes at the PET/KOH weight ratios of 1:1, 1:3, and 1:5 and by carbonization then of the resulting products at 850 °C for 2 h in N atmosphere. The activation in steam was performed by heating at 900 °C for 1 h. The ACs were characterized by N adsorption at - 196 °C, mercury porosity, mercury density measurements, FT-IR spectroscopy, and measurement of pH of the point of zero charge (pH). The activation yield is 58.4-49.4% with KOH in aqueous solution, 75.8-23.9% with solid KOH, and 5.9% with steam. Using solid KOH, greater developments of a more heterogeneous porosity with increasing impregnation PET/KOH ratio are achieved. For SK1:5, S is 1990 m g and the pore volumes are 0.71 cm g, micropores; 0.81 cm g, mesopores; and 1.77 cm g, macropores. The data of BPA adsorption fit better to the Ho and Mckay second order kinetic model than to the Lagergren first-order kinetic model and to the Langmuir equation than to the Freundlich equation. From the kinetic and thermodynamic standpoints, the adsorption process of BPA is more favorable for SK1:5.
本研究涉及从聚对苯二甲酸乙二醇酯（PET）废物中制备活性炭（AC），以及 AC 的物理化学特性及其在水溶液中作为双酚 A（BPA）吸附剂的用途。AC 通过 KOH 的化学活化和蒸汽的物理活化来制备。通过湿浸渍和干浸渍首先用 KOH 浸渍 PET，PET/KOH 重量比为 1:1、1:3 和 1:5，然后在 N 气氛中于 850°C 下碳化所得产物 2 小时，进行 KOH 活化。蒸汽活化通过在 900°C 下加热 1 小时进行。AC 通过在-196°C 下进行氮气吸附、压汞孔隙率、压汞密度测量、FT-IR 光谱和零电荷点（pH）的 pH 值测量进行表征。在水溶液中用 KOH 进行活化时，产率为 58.4-49.4%，用固体 KOH 进行活化时，产率为 75.8-23.9%，用蒸汽进行活化时，产率为 5.9%。使用固体 KOH，可以实现随着浸渍 PET/KOH 比的增加而更均匀的更具异质性的孔隙度的更大发展。对于 SK1:5，S 为 1990 m²/g，孔体积分别为 0.71 cm³/g，微孔；0.81 cm³/g，中孔；和 1.77 cm³/g，大孔。BPA 吸附的数据更符合 Ho 和 McKay 二级动力学模型，而不是 Lagergren 一级动力学模型，更符合 Langmuir 方程，而不是 Freundlich 方程。从动力学和热力学的角度来看，BPA 的吸附过程对于 SK1:5 更为有利。
