Behavior of two classes of organic contaminants in the presence of graphene oxide: Ecotoxicity, physicochemical characterization and theoretical calculations.

Autor: Magalhães de Paula TN; School of Technology, University of Campinas - Unicamp, CEP: 13484-332 Limeira, São Paulo, Brazil., Souza Vendemiatti JA; School of Technology, University of Campinas - Unicamp, CEP: 13484-332 Limeira, São Paulo, Brazil., Camparotto NG; School of Technology, University of Campinas - Unicamp, CEP: 13484-332 Limeira, São Paulo, Brazil., Toledo B; School of Technology, University of Campinas - Unicamp, CEP: 13484-332 Limeira, São Paulo, Brazil., Oliveira ÁC; School of Technology, University of Campinas - Unicamp, CEP: 13484-332 Limeira, São Paulo, Brazil., Neves TF; School of Technology, University of Campinas - Unicamp, CEP: 13484-332 Limeira, São Paulo, Brazil., Umbuzeiro GA; School of Technology, University of Campinas - Unicamp, CEP: 13484-332 Limeira, São Paulo, Brazil., Prediger P; School of Technology, University of Campinas - Unicamp, CEP: 13484-332 Limeira, São Paulo, Brazil. Electronic address: prediger@unicamp.br.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 May 20; Vol. 822, pp. 153515. Date of Electronic Publication: 2022 Jan 29.
DOI: 10.1016/j.scitotenv.2022.153515
Abstrakt: Graphene oxide (GO) production has increased considerably and therefore its presence in the environment is inevitable. When in aquatic environment GO can interact with co-existing compounds, modifying their toxicities for several organisms. However, the toxic effects of co-exposure of GO and organic compounds are rarely reported in the literature. Herein, we studied the behavior of four organic aquatic contaminants found in surface water such as 2-phenylbenzotriazoles (non-Cl PBTA-9 and PBTA-9) and phenoxyphenyl pesticides, pyriproxyfen (PYR) and lambdacyhalothrin (LCT), in the presence of GO. GO reduced 90% and 83% of the toxicity of non-Cl PBTA-9 and PBTA for Daphnia. When PBTAs were adsorbed onto GO surface their interactions caused GO agglomeration (up to 20 mm) and consequent precipitation, making PBTAs less bioavailable. PYR and LCT's toxicities increased up to 83% for PYR and 47% for LCT in the presence of GO, because their adsorption on GO lead to the stabilization of the suspensions (up to 0.5 μm). Those particles were then easily ingested and retained in the digestive tract of the daphnids, triggering the Trojan horse effect. Based on theoretical calculations we observed that PBTA compounds are planar, electron-poorer and more reactive than the studied pesticides, suggesting a better stability of the GO/PBTA complexes. PYR and LCT are nonplanar, electron-richer and less reactive towards GO than PBTAs, forming less stable GO complexes that could facilitate the desorption of pesticides, increasing toxic effects. Our results suggest that the properties of the organic toxicants can influence the stability of graphene oxide suspensions, playing a fundamental role in the modulation of their toxicity. Further research is needed for a deep understanding of the behavior of nanomaterials in the presence of contaminants and their effect in the toxicity of aquatic organisms.
Competing Interests: Declaration of competing interest There are no conflicts to declare.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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