Investigation of the Distribution and Transformation of Persistent Organic Compounds in Plastic Waste Recycling Processes

The recycling of plastic waste has emerged as a critical challenge due to the presence and transformation of persistent organic compounds (POCs), which pose environmental and health risks. This review investigates the distribution, concentration, and chemical transformation of six representative POCs in plastic waste: bisphenol A (BPA), phthalates (e.g., DEHP), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), perand polyfluoroalkyl substances (PFASs), and dioxins/furans. Concentrations of DEHP in PVC, for instance, reach up to 130 µg/g, while BPA levels in ABS can exceed 15 µg/g. Using data compiled from recent literature, we analyze how mechanical and thermal recycling processes influence the release or degradation of these compounds. Thermal treatments at 400–500 °C have been shown to generate up to 1.2 ng/g of dioxins. Furthermore, we examine mitigation strategies, such as solvent extraction and chemical recycling, which achieve POC removal efficiencies of 85–95%. This review highlights the trade-off between process efficiency and pollutant generation and underscores the importance of integrating removal technologies into recycling systems. Our analysis provides a scientific basis for optimizing plastic waste management while minimizing chemical risks.