Modelling of the adsorption of chlorinated phenols on polyethylene and polyethylene terephthalate microplastic

Abstract

The role of microplastics (MPs) on the fate and transport of various pollutants in water matrices is of major concern, but it is still relatively under investigated. In order to consider the conditions in real aquatic environments, the changes to polyethylene (PE) structure during the fabrication of microplastic particles for specific uses should not be neglected. Thus, this work considers isolated PE from two types of personal care products, which are possible sources of microplastic contamination in aquatic environments. The adsorption affinity of these PE microplastics towards ionisable compounds was compared with those of standards of PE and polyethylene terephthalate (PET), using chlorinated phenols (4-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol and pentachlorophenol) as adsorbates. The pseudo-second order kinetic model described well the sorption process for all chlorinated phenols on all four types of MPs (R 2 range: 0.900-0.998). The kinetic study showed that sorption rates are mainly controlled by hydrophobic interactions and molecule size. Adsorption isotherms were best described by the Freundlich model for all MPs. The obtained results indicate that MPs could serve for the transport of chlorinated phenols through ambient waters.

Adsorption of PAHs and PCDD/Fs in Microplastics: A Review

“…Lončarsk et al [57] used the second-order model to estimate the kinetics of the adsorption process of PAHs on poly lactic acid (PLA), which implies that chemisorption is the adsorption mechanism involved.…”

“…Černá et al [29] studied the differences in the adsorption of PAHs in biodegradable and conventional polyurethane, observing a much faster adsorption in the biodegradable. In contrast, Lončarsk et al [57] studied the adsorption of PAHs in PLA (biodegradable), this being very slow and of little relevance. The adsorption of dioxin-like compounds has not been studied in such depth, perhaps due to the difficulty of analyzing these compounds.…”

Interactions Between Microplastics and Heavy Metals in Aquatic Environments: A Review

“…As simple non-polar crystalline polymers, PE and PP have no functional groups and can only adsorb contaminants in a single layer with van der Waals forces, so the adsorption capacity is relatively small (Chen et al, 2019). For PS and PET, the polarity is increased due to the presence of phenyl and ester groups, and the adsorption capacity can be increased through the interaction of π-π bonds with pollutants (Llorca et al, 2020;Loncarski et al, 2020). PVC, because it contains polar atomic chlorine, is a strong polar polymer, so it has very large adsorption capacity (Brennecke et al, 2016).…”

Sorption Behavior of Organic Pollutants on Biodegradable and Nondegradable Microplastics: pH Effects

“…In this regard, previous research results have implied that the surfaces of polyethylene and polystyrene particles change and protonate with decreases in pH, consequently increasing the sorption of organic pollutants, such as perfluorooctane sulfonate, chlorinated phenols and others [3,[21][22][23]. Moreover, variable pHs in the surrounding water may change the ionization states of pollutants and influence their sorption processes on MPs [3,[21][22][23]. Among the various studies investigating the adsorption of various organic pollutants (such as pesticides or pharmaceuticals) on a number of MPs [23][24][25][26][27][28][29][30][31][32][33][34][35], pH was not always considered.…”

“…Several studies have emphasized the impact of pH as an environmental factor in increasing or inhibiting the adsorption capacity depending on the polymer type as well as the type of pollution [19,20]. In this regard, previous research results have implied that the surfaces of polyethylene and polystyrene particles change and protonate with decreases in pH, consequently increasing the sorption of organic pollutants, such as perfluorooctane sulfonate, chlorinated phenols and others [3,[21][22][23]. Moreover, variable pHs in the surrounding water may change the ionization states of pollutants and influence their sorption processes on MPs [3,[21][22][23].…”