Sorption Behavior and Mechanisms of Organic Contaminants to Nano and Microplastics

Abstract

Nano and microplastics (NPs/MPs) have received widespread attention in recent years. Because of their large specific surface area and hydrophobicity, NPs/MPs can adsorb various organic contaminants. This article gives a brief review of the sorption behavior of organic contaminants to NPs/MPs, summarizes the possible sorption mechanisms, and analyzes the influencing factors in the environment on the sorption behavior and mechanisms of NPs/MPs. The main mechanisms of sorption of organic contaminants to NPs/MPs are partitioning, surface sorption (hydrogen bonding, π–π interaction, electrostatic interaction, and van der Waals force), and pore filling. The sorption behavior of organic contaminants to NPs/MPs is not only affected by the properties of the NPs/MPs and the organic contaminants, but also by the solution chemistry, such as the pH, ionic strength, and dissolved organic matter.

Organic Contaminants and Interactions with Micro- and Nano-Plastics in the Aqueous Environment: Review of Analytical Methods

“…Recently, many reviews have been published dealing with interactions between plastic particles (micro and nano) and TOrCs [ 8 , 9 , 11 , 92 , 93 , 94 , 95 ]. Firstly, the plastic itself is examined more closely, including polymer type, the specific surface of the particles with their functional groups and physicochemical properties, crystallinity, polarity, and additives [ 8 , 16 , 55 , 92 , 96 ].…”

“…Firstly, the plastic itself is examined more closely, including polymer type, the specific surface of the particles with their functional groups and physicochemical properties, crystallinity, polarity, and additives [ 8 , 16 , 55 , 92 , 96 ]. The factors of the surrounding matrix, such as salinity, pH, dissolved organic matter (DOM), coexisting organic contaminants, and ionic strength [ 9 , 93 ] are also considered. The main retention mechanisms from TOrCs to micro- and nanoplastics are pore filling, hydrophobic hydrogen bonding, π-π-, electrostatic interactions, and van der Waals forces [ 9 ].…”

“…The factors of the surrounding matrix, such as salinity, pH, dissolved organic matter (DOM), coexisting organic contaminants, and ionic strength [ 9 , 93 ] are also considered. The main retention mechanisms from TOrCs to micro- and nanoplastics are pore filling, hydrophobic hydrogen bonding, π-π-, electrostatic interactions, and van der Waals forces [ 9 ]. A further important issue is the ageing of polymers and the resulting influence on the sorption of TOrCs [ 97 ].…”

“…A FTIR analysis is possible up to 10 µm, a Raman analysis is limited to 100 nm [ 108 , 109 ]. The relationship between particle, surface size, and sorption capacity is considered in more detail in the recently published review by Wang et al, 2020 [ 9 ].…”

“…In recently published reviews, sorption of trace organic chemicals (TOrCs) on micro- and nanoplastics has already been examined in detail [ 8 , 9 , 10 , 11 ]. In these studies, the focus is on the influence of the physical properties of particles (such as size, surface, crystallinity) and the resulting interaction properties of TOrCs and polymers.…”