Innovative processes and technologies for plastic waste valorization and implications for the green economy

Abstract

Plastic waste accumulation poses a growing environmental challenge, with macroplastics contributing to resource inefficiency and micro- and nanoplastics emerging as persistent hazardous pollutants in aquatic, terrestrial, and atmospheric environments. This review critically examines contemporary plastic waste management and valorization technologies within a circular economy framework, with a clear distinction between macroplastic resource recovery and micro- and nanoplastic risk mitigation. While macroplastics can be sustainably valorized through mechanical recycling, chemical depolymerization, and thermochemical conversion, micro- and nanoplastics are internationally recognized as contaminants requiring prevention, capture, containment, and irreversible destruction or immobilization rather than reuse. Accordingly, the review evaluates capture technologies, terminal thermal and catalytic destruction, advanced oxidation and mineralization processes pathways for mitigating micro- and nanoplastic hazards. Emerging tools such as artificial intelligence and smart monitoring systems are also discussed in the context of improving plastic waste management efficiency and preventing secondary microplastic contamination. By clarifying the distinct treatment strategies required for different plastic size classes, this work provides a balanced and precautionary perspective to inform sustainable plastic management policies and future research directions.