Chapter 7: Mass Transfer of Organic Compounds at Plastic Interfaces – Why Chemical Complexity and Environmental Factors Matter

Plastics contain complex mixtures of organic compounds including functional additives admixed during the manufacturing process. Non-intentionally added substances (NIAS) can enter plastics during their life cycle. The leaching of plastic-associated contaminants into the environment is concerning because of their possible adverse health effects for ecosystems and humans. To assess the fate and impact of plastic-associated organic compounds, mass transfer processes from/to plastics must be better understood. These processes have been investigated in recent experimental studies individually but a comprehensive assessment considering the chemical complexity of both plastics and organic compounds, and the impact of environmental factors is lacking. This chapter analyzes molecular interactions of organic compounds at plastic interfaces. It explores the fundamentals of mass transfer mechanisms, that is, adsorption and absorption, and sorption kinetics. We discuss the impact of abiotic and biotic factors – flow conditions, temperature, salinity, UV irradiation, biofilm formation, and the presence of dissolved organic matter – on the mass transfer process and kinetics of plastic-associated compounds with a focus on aquatic environments.