Adsorption of bisphenol A by activated carbon developed from PET waste by KOH activation

• Published in: Environmental science and pollution research international 2021-05, Vol.28 (19), p.24342-24354
• Main Authors: Gómez-Serrano, Vicente, Adame-Pereira, Marta, Alexandre-Franco, María, Fernández-González, Carmen
• Format: Article
• Language: English
• Subjects: Activated carbon; Adsorption; Aquatic Pollution; Aqueous solutions; Atmospheric Protection/Air Quality Control/Air Pollution; Bisphenol A; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Impregnation; Infrared spectroscopy; Mercury; Polyethylene terephthalate; Porosity; Waste and Biomass Management & Valorization; Waste Water Technology; Water Management; Water Pollution Control
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-020-08428-6

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 2 atmosphere. The activation in steam was performed by heating at 900 °C for 1 h. The ACs were characterized by N 2 adsorption at − 196 °C, mercury porosity, mercury density measurements, FT-IR spectroscopy, and measurement of pH of the point of zero charge (pH pzc ). 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 BET is 1990 m 2  g −1 and the pore volumes are 0.71 cm 3  g −1 , micropores; 0.81 cm 3  g −1 , mesopores; and 1.77 cm 3  g −1 , 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.