湖泊悬沙对塑料老化裂解及其浸出液的影响OA

Microplastics are a relatively new pollutant,and their environmental behavior in the aquatic environment has become a research hotspot in recent years.After biodegradation,weathering processes(such as photooxidation and mechanical wear),will alter the surface morphology and physiochemical properties of microplastics discharged into water,accompanied by the release of substances leached from the plastic.Mechanical degradation is important to the aging and deterioration of plastics and plays a cru-cial role in the migration and transformation of plastics.In this study,we explored the effects of different concentrations of suspended particulate matter on the aging and leaching of plastics,aiming to provide a scientific basis for assessing the ecological risk and regulating plastic pollution.Cellophane(CP),the most abundant type of plastic in the water of Taihu Lake,was selected for research,and a 28-day aging experiment of CP was conducted with five suspended particulate matter treatments(0,50,100,250,500 mg/L).The conclusions are as follows:(1)CP was mechanically degraded layer by layer,with surface roughening,peeling and hole formation during the aging process.The high concentration of suspended particles(500 mg/L)significantly inhibited the photooxidative degradation of CP,resulting in obviously weaker aging characteristics compared with the low concentration groups.(2)The aging process altered the molecular structure of CP,decreasing the oxygen to carbon ratio.(3)The variation trends of DOC con-centration in the CP leachate differed under the influence of varying concentrations of suspended particu-late matter.(4)Tryptophan and tyrosine were released from CP during aging,and the CP fluorescence in-dex decreased with time when exposed to sunlight.