Cyclodextrin-silica hybrid materials: synthesis, characterization, and application in pesticide aqueous removal

Author(s)

Baigorria, Estefania ; Carvalho, Lucas Braganca ; Pinto, Luciana Matos Alves ; Fraceto, Leonardo Fernandes

• Document type: Journal article
• Source: RONTIERS IN CHEMISTR; v. 12, p. 14-pg., 2024-08-29.

Abstract

Introduction Overusing and misusing pesticides, including paraquat (PQ), have led to numerous environmental contamination complications. PQ is an emerging bio-accumulative contaminant that is present in environmental aqueous matrices. Adsorption techniques are part of a set of technologies applied in ecological remediation, known for their high effectiveness in removing aqueous PQ. A study of the PQ adsorption capacity of three cyclodextrin-silica nanocomposites (alpha-CDSi, beta-CDSi, and gamma-CDSi) from contaminated waters is presented in this paper.Methods The cyclodextrin-silica nanocomposites were synthesized via an esterification reaction between the inorganic matrix and cyclodextrins (CDs) (alpha, beta, and gamma) and were characterized physicochemically by spectroscopic, thermal, and surface methods. Their PQ removal performance from contaminated aqueous media was studied under different experimental conditions.Results and Discussion The results showed a fast adsorptive response in removal treatment studies over time. Adsorption capacities of 87.22, 57.17, and 77.27 mg.g-1 were found for alpha-CDSi, beta-CDSi, and gamma-CDSi, respectively, at only 30 min of treatment. Thermodynamic studies indicated spontaneous and exothermic adsorption processes. The removal assays responded mainly to physisorption mechanisms with contributions from chemisorption mechanisms. Spectroscopic assays showed a strong interaction of PQ with the adsorbents used. Innovative CDSi nanocomposites have proven to be highly efficient in applying aqueous PQ remediation, thus proving to be sustainable adsorbents of contaminants of emerging importance worldwide. (AU)

• FAPESP's process: 17/21004-5 - Agriculture, micro/nanotechnology and environment: from evaluation of the mechanisms of action to studies of transport and toxicity
• Grantee: Leonardo Fernandes Fraceto
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/23608-8 - Development of labelled nanopesticides aiming studies of mechanism of action and toxicity
• Grantee: Lucas Bragança de Carvalho
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 21/10639-5 - Center for Research on Biodiversity Dynamics and Climate Change
• Grantee: Leonor Patricia Cerdeira Morellato
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC