Insights into sorption and molecular transport of atrazine, testosterone, and progesterone onto polyamide microplastics in different aquatic matrices

Author(s)

Dias, Mariana A. ; Batista, Patrick R. ; Ducati, Lucas C. ; Montagner, Cassiana C.

• Document type: Journal article
• Source: Chemosphere; v. 318, p. 10-pg., 2023-02-01.

Abstract

Microplastics can act as vectors of a wide class of contaminants in aquatic environments. The sorption behavior of two hormones known to cause adverse effects in biota even in low concentrations (testosterone-TTR and progesterone-PGT), and a pesticide with a high environmental persistence known as endocrine disruptor chemical (atrazine-ATZ) onto polyamide (PA) microplastics is investigated under different aquatic matrices using kinetic and isotherm experiments. The sorption equilibrium is achieved in 48 h, and the experimental results are better fitted by pseudo-2nd-order model. Langmuir isotherm better describes the sorption of the contaminants onto PA microplastics. PGT presents the highest sorption efficiency at around 90%, followed by TTR at 70% and ATZ at approximately 20%. Moreover, ATZ is the contaminant with the highest desorption efficiency (similar to 65%), indicating its preference for staying solubilized in water. Combining classical molecular dynamics and density functional theory calculations, the sorption energies were calculated as 12-15 kcal mol(-1), 13-16 kcal mol(-1), and 19-22 kcal mol(-1) for PGT, TTR, and ATZ, respectively, showing that PGT needs less energy to be transferred from the solvent network to the PA surface, in agreement with experimental results. The sorption mechanism is driven by hydrogen bonds onto PA outer surface, while the electrostatic interactions dominate the PA inner surface sorption. Moreover, the sorption efficiency is statistically different between the investigated matrices, indicating that physicochemical characteristics of water systems could influence the interactions between PA-contaminant. In seawater, the phenomena of salting-out/in and competitive sorption with saline ions are observed for three contaminants. The PA-contaminant complexes are more polar and soluble than the dissociated ones, which increases the contaminant's co-transport by PA in water. (AU)

• FAPESP's process: 18/21733-0 - Microplastics as transport vectors of organic emerging contaminants in Brazilian aquatic matrices
• Grantee: Cassiana Carolina Montagner
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/50951-4 - INCT 2014: Advanced Analytical Technologies
• Grantee: Celio Pasquini
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/17750-3 - Solvent Effect in NMR Parameters by ab initio Molecular Dynamics
• Grantee: Lucas Colucci Ducati
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/10246-0 - Nuclear magnetic resonance spectroscopy: from pulse sequences to structural assignments
• Grantee: Claudio Francisco Tormena
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/18790-3 - Environmental effects of the pasture-sugarcane conversion and pasture intensification
• Grantee: Luiz Antonio Martinelli
• Support Opportunities: Research Program on Global Climate Change - Thematic Grants
• FAPESP's process: 08/57808-1 - National Institute of Advanced Analytical Science and Technology
• Grantee: Celio Pasquini
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/07308-4 - Effect of solvent on shielding tensor and coupling constant calculations of platinum (iii) dinuclear complexes via ab initio molecular dynamics
• Grantee: Patrick Rodrigues Batista
• Support Opportunities: Scholarships in Brazil - Doctorate