Comparative evaluation of sorption kinetics and isotherms of pyrene onto microplastics

• Published in: Chemosphere (Oxford) Vol. 193; pp. 567 - 573
• Main Authors: Wang, Wenfeng, Wang, Jun
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-02-2018
• Subjects: Adsorption; Diffusion; Isotherms; Kinetics; Microplastics; Models, Chemical; Organic Chemicals; Plastics - analysis; Plastics - chemistry; Polycyclic Aromatic Hydrocarbons - analysis; Polyethylene; Pyrene; Pyrenes - analysis; Pyrenes - chemistry; Sorption; Water Pollutants, Chemical - analysis; Sorption; Pyrene; Microplastics; Kinetics; Isotherms
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2017.11.078

Concerns regarding microplastics pollution and their potential to concentrate and transport organic contaminants in aquatic environments are growing in recent years. Sorption of organic chemicals by microplastics may affect the distribution and bioavailability of the chemicals. Here sorption process of pyrene (Pyr), a frequently encountered polycyclic aromatic hydrocarbon in aquatic environments, on three types of mass-produced plastic particles (high-density polyethylene (PE), polystyrene (PS) and polyvinylchloride (PVC)), was investigated by comparative analysis of different sorption kinetic and isotherm models. Optimum kinetic and isotherm models were predicted by the linear least-squares regression method. The pseudo-second-order kinetic model was more appropriate in describing the entire sorption process (R2 > 0.99). Sorption rates of Pyr onto microplastics were mainly controlled by intraparticle diffusion. PE exhibited the highest affinity for Pyr, followed by PS and PVC. The sorption equilibrium data were best fitted to the Langmuir isotherm (R2 > 0.99), indicating monolayer coverage of Pyr onto the microplastics.
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•Sorption kinetics and isotherms of pyrene onto microplastics were studied.•Sorption of pyrene followed the order of PE > PS > PVC.•Pseudo-second-order model was appropriate to describe the sorption kinetics.•Sorption equilibrium data were best fitted to the Langmuir model.