Adsorption of 17 alpha-ethinylestradiol onto a novel nanocomposite based on graphene oxide, magnetic chitosan and organoclay (GO/mCS/OC): Kinetics, equilibrium, thermodynamics and selectivity studies

Author(s)

Almeida, Arthur da Silva Vasconcelos de ; Mastelaro, Valmor Roberto ; Silva, Meuris Gurgel Carlos da ; Prediger, Patricia ; Vieira, Melissa Gurgel Adeodato

• Document type: Journal article
• Source: JOURNAL OF WATER PROCESS ENGINEERING; v. 47, p. 18-pg., 2022-06-01.

Abstract

17 alpha-ethinylestradiol (EE2) is a synthetic estrogen present in contraceptive pills, being considered an emerging contaminant. In this work, EE2 adsorption process in a nanocomposite of graphene oxide, magnetic chitosan and organophilic clay (GO/mCS/OC) was evaluated. The nanocomposite was characterized by nitrogen phys-isorption, thermogravimetry, X-ray diffraction, X-ray photoelectric spectroscopy, Fourier transform infrared spectroscopy, Raman spectroscopy and scanning electron microscopy. The effects of dosage, sonication time and pH on the process were assessed. Kinetics, equilibrium, thermodynamics and reusability tests of EE2 adsorption onto GO/mCS/OC were investigated. The adsorptive kinetics of EE2 followed a pseudo-second order model, while the equilibrium was better represented by the BET model, with a characteristic profile of multilayer physisorption. Thermodynamics suggested that the process was spontaneous and endothermic. Adsorption mechanisms were assessed, indicating an important role of oxygenated and nitrogenated functional groups, as well as the aromatic structure of the GO/mCS/OC, promoting H-bonds and pi-pi interactions. The nanoadsorbent had a maximum experimental capacity of 50.5 mg g(-1) (30 degrees C). The selectivity of the nanocomposite in binary solutions with bisphenol A (BPA) revealed satisfactory removal efficiency, good selectivity and material stability. The GO/OC nanocomposite showed reuse potential for two consecutive cycles, decreasing its capacity until the fifth adsorptive cycle. Finally, the developed nanocomposite proved to be a promising alternative for removing emerging contaminants from aquatic matrices. (AU)

• FAPESP's process: 19/07822-2 - Synthesis of new nanoadsorbents, their characterizations and applications in pollutant adsorption in water
• Grantee: Patricia Prediger
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/16004-9 - Development of advanced materials and artificial intelligence-based models for application for the removal and monitoring of emerging pollutants in aqueous media
• Grantee: Meuris Gurgel Carlos da Silva
• Support Opportunities: Regular Research Grants