Sorption of Hydrophobic Organic Compounds to Plastics in the Marine Environment: Sorption and Desorption Kinetics

Abstract

The interaction of plastics with hydrophobic organic compounds (HOCs) is well established. Several HOCs are known carcinogens and/or endocrine disruptors. To determine how chemicals in plastic affect the marine environment, it is necessary to understand the kinetics of HOC sorption/desorption. This includes the understanding of sorption kinetics and mechanisms along with simple modeling concepts such as the first order rate kinetic model that can often adequately describe the overall phenomenon. However, to more mechanistically understand the chemical uptake and desorption process, the diffusion of chemicals in plastic is also discussed as well as the direct observation of this process in sectioned plastic particles. Moreover, modeling is required to understand the diffusion of chemicals in microplastic particles. In addition, case studies from the literature are presented which seek to understand how compounds move in and out of the plastics found in the marine environment or when in contact with other fluids besides seawater such as stomach fluids or fish oil.