Safety assessment of polypropylene recovery from waste lunchboxes through photoelectric-identification-coupled...

The recycling of waste polypropylene (PP) lunchboxes is an important component of achieving low-carbon and sustainable development. This study conducts a systematic analysis of the recycling process for waste PP lunchboxes. By clarifying the performance differences, volatile organic compounds component characteristics, and safety compliance of recycled PP particles of different colors, it provides key data support for targeted optimization of recycling PP lunchboxes. Combined with material flow analysis, this study quantifies resource consumption (e.g., 5462.4 kWh of electricity consumed daily) and output efficiency (61.19 % total recovery rate) in the recycling process, offering a promotable technical strategy for building a high environmental benefit recycling system. Safety assessments confirm that recycled transparent PP was not detected to contain the organic substances of high concern listed in the REACH SVHCs, with concentrations below 0.05 mg/kg. The safety verification breaks the perception that recycled materials cannot be used in high-safety-demand scenarios, providing a scientific basis for promoting closed-loop recycling of waste PP. The analysis and optimization suggestions for technical bottlenecks in photoelectric color sorting (such as difficulty in identifying light-colored flakes and high equipment iteration costs) point out the direction for industrial technological upgrading, contributing to enhancing the large-scale and intelligent level of China's waste plastic recycling industry.