Agar/graphene oxide hydrogels as nano-bioadsorbents: a comparative analysis for dye removal

• Type: Article in International Scientific Journal
• Date: 2023

Authors

de Araujo, CMB (Author) Other; Rios, AG (Author) Other; Alexandre Ferreira (Author) FEUP; Sobrinho, MAD (Author) Other; Rodrigues, AE (Author) Other; Ghislandi, MG (Author) Other

Journal

Title: Environmental Science and Pollution Research

ISSN: 0944-1344

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 0 Citations

Other information

Authenticus ID: P-00Z-JWJ

DOI: 10.1007/s11356-023-31158-4

Abstract (EN): Nano-biocomposite hydrogel samples were produced using graphene oxide (GO) and agar and applied as adsorbents of organic components in water. The hydrogels were prepared by varying the wt% of Agar and GO. The samples were characterized, and batch adsorption experiments evaluated the effect of initial pH, equilibrium isotherms, and kinetics for the adsorption of the anionic dye Acid Orange 7 (AO) and the cationic dyes Nile Blue A (NB) and methylene blue (MB) in an aqueous medium. Overall, both hydrogel samples exhibited satisfactory results for removing NB and MB; however, there was no effective removal for the anionic dye AO. Adsorption equilibrium isotherms were obtained, and Freundlich, Langmuir, and Sips models were fitted to the experimental equilibrium data; moreover, kinetic data were adjusted to driving force models and particle mass balance. The maximum experimental adsorption capacities, 141.48 mg center dot g-1 (MB) and 284.69 mg center dot g-1 (NB), were obtained, on a dry basis, for the sample produced with 70 wt% of agar and 30 wt% of GO. Both hydrogels exhibited remarkable regenerative potential for NB and MB, with the adsorption capacity remaining constant, even after five adsorption/desorption cycles.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 13