This aging experiment, with a period of 3 months (one month was 30 days, which was defined as a cycle), were conducted with continuous UV irradiation.15 of the plastic pellets in each solution environment were randomly removed in each cycle, and then the surface solutions of the removed samples were dried with absorbent papers.After that, these samples were dried at 60 °C and stored in glass containers in the dark Meanwhile, 15 of the plastic pellets in the air environment were also randomly selected out of each cycle for analysis.