Investigation of the adsorptive capacity of a poly(vinyl alcohol)-based film for sodium diclofenac in aqueous media

Authors

  • Juliana Zanol Merck Universidade de Caxias do Sul, Área do Conhecimento de Ciências Exatas e Engenharias, Rua Francisco Getúlio Vargas, 1130, Caxias do Sul 95070-560, Brazil.
  • Camila Suliani Rota Universidade de Caxias do Sul, Área do Conhecimento de Ciências Exatas e Engenharias, Rua Francisco Getúlio Vargas, 1130, Caxias do Sul 95070-560, Brazil. https://orcid.org/0000-0002-1613-8675
  • Jocelei Duarte Universidade de Caxias do Sul, Área do Conhecimento de Ciências Exatas e Engenharias, Rua Francisco Getúlio Vargas, 1130, Caxias do Sul 95070-560, Brazil. https://orcid.org/0000-0003-2418-8397
  • Camila Baldasso Universidade de Caxias do Sul, Área do Conhecimento de Ciências Exatas e Engenharias, Rua Francisco Getúlio Vargas, 1130, Caxias do Sul 95070-560, Brazil. https://orcid.org/0000-0001-5763-8724
  • Marcelo Giovanela Universidade de Caxias do Sul, Área do Conhecimento de Ciências Exatas e Engenharias, Rua Francisco Getúlio Vargas, 1130, Caxias do Sul 95070-560, Brazil. https://orcid.org/0000-0003-0874-383X
  • Janaina da Silva Crespo Universidade de Caxias do Sul, Área do Conhecimento de Ciências Exatas e Engenharias, Rua Francisco Getúlio Vargas, 1130, Caxias do Sul 95070-560, Brazil. https://orcid.org/0000-0002-0935-242X

DOI:

https://doi.org/10.18226/23185279.e241305

Keywords:

Poly(vinyl alcohol), citric acid, crosslinked film, sodium diclofenac, adsorption, isotherms, kinetics

Abstract

Sodium diclofenac (DCF) has been detected in waters worldwide and is considered a micropollutant of emerging concern due to its potential toxicity in aquatic and terrestrial ecosystems. Traditional water treatment methods are unable to remove DCF completely from water, which makes adsorptive films a suitable alternative to address this challenge. In this context, the present study investigated the adsorptive capacities of a poly(vinyl alcohol)-based film for removing DCF from aqueous solutions. The effects of the initial DCF concentration and solution pH on the adsorption performance were evaluated, as well as kinetics and equilibrium isotherms. Regarding the results, DCF precipitation was observed within a pH range of 4.0-7.0, probably due to its limited solubility in acidic media. The optimal DCF concentration was found to be the lowest tested (2.5 mg L-1), yielding an equilibrium adsorption capacity (qe) of 0.511 mg g-1 and a DCF removal percentage (%R) of 23.4% within 90 min. Although the adsorption equilibrium was well described by the Redlich-Peterson isotherm despite the unusual behavior observed, pseudo-first and pseudo-second order kinetic models were satisfactory only at the initial concentration of 2.5 mg L⁻¹. Overall, the data set indicate that the film has a limited adsorption capacity, reaching saturation at low adsorbate concentrations. Nonetheless, these findings support further investigations at lower DCF concentrations to better understand the film’s adsorptive behavior under environmentally relevant conditions.

Additional Files

Published

11/21/2024

How to Cite

Zanol Merck, J., Suliani Rota, C., Duarte, J., Baldasso, C., Giovanela, M., & da Silva Crespo, J. (2024). Investigation of the adsorptive capacity of a poly(vinyl alcohol)-based film for sodium diclofenac in aqueous media. Scientia Cum Industria, 13(1), e241305. https://doi.org/10.18226/23185279.e241305

Issue

Section

Original Research