Magnetic nanosorbents of γ-polyglutamic acid for removing a β-blocker from water

abstract

Metoprolol is known as one of the most frequently used beta-blockers to treat hypertension, however due to its widespread use and resistance to hydrolysis, concerning amounts of this medicine are found in surface waters, causing negative impacts on the environment and human health. To date, very few water treatment plants remove metoprolol due to the ineffectiveness of conventional procedures, thus indicating the need for more efficient water treatments for eliminating traces of this drug from aqueous wastes. A promising strategy is the development of magnetic assisted sorbents with a high surface area and adequate chemical modification aimed at the target pollutant, offering the possibility of total removal from water supplies and thus limiting potential environmental impacts. In this context, the purpose of this work was to investigate the application of magnetic Fe3O4 nanoparticles coated with silica and.-polyglutamic acid to capture metoprolol dissolved in water. The synthesized sorbents consisted of magnetite nanoparticles with an average size of 55.8 nm, coated with a layer of amorphous silica covalently bound to.-polyglutamic acid, thus exposing carboxylate surface active sites, which favor electrostatic interactions with metoprolol. As the.-polyglutamic acid sources, two types of materials with distinct amounts in the biopolymer (30% and 92%) have been investigated. The adsorption of metoprolol by the nanosorbents gamma-PGA/Fe3O4 was evaluated by means of adsorption isotherms and theoretical adsorption models. Freundlich and Langmuir models provide an accurate description of the isotherm, and the compound's maximum adsorption capacity was 571.6 mg g(-1). Noteworthy, the magnetic nanosorbents prepared using.-polyglutamic acid 30% and 92% have shown comparable performances, which makes this process also economically attractive considering that a low-cost raw material can be used.

keywords

EMERGING POLLUTANTS; WASTE-WATER; SOLID-STATE; IRON-OXIDES; METOPROLOL; NANOPARTICLES; PHOTODEGRADATION; ADSORPTION; PARTICLES; TOXICITY

subject category

Engineering

authors

Campos, V; Marques, DG; Nogueira, J; Amorim, CO; Daniel-da-Silva, AL; Trindade, T

Groups

G1 - Porous Materials and Nanosystems
G6 - Virtual Materials and Artificial Intelligence

Projects

Collaboratory for Emerging Technologies, CoLab (EMERGING TECHNOLOGIES)

Bionanocompósitos magnéticos para a remoção de micropoluentes e reutilização da água (BIOMAG)

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

Rede Nacional de Ressonância Magnética Nuclear (PTNMR)

acknowledgements

This research was financed by the Sao Paulo Research Foundation, FAPESP (Fellowship Grant no 2021/08619-6), and IGTPAN - Granado Polyacrylonitrile Technology Institute. We also wish to thank the botanical illustrator, Klei Sousa, for his contribution to this work. We thank funding of Portugal 2020 through European Regional Development Fund (ERDF) in the frame of CENTRO2020 in the scope of the project BIOMAG, CENTRO-01-0247-FEDER-181268 and in the scope of the project CICECO-Aveiro Institute of Materials UIDB/50011/2020 & UIDP/50011/2020 & LA/P/0006/2020. J. Nogueira thanks the Fundacao para a Ciencia e Tecnologia (FCT) for the PhD Grant SFRH/BD/146249/2019. The NMR spectrometers are part of the National NMR Network (PTNMR) and are partially supported by Infrastructure Project no & nbsp;022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL and FCT through PIDDAC).