Characterization and ecological risk assessment of microplastics in sediments of the upper Han River
As an important sink for microplastics,sediments are potential receptors and major storage sites for them.In order to understand the pollution status of microplastics in the water body sediments of the upper reaches of the Han River,methods such as density flotation-oxidation digestion separation and extraction,observation with an optical microscope and a scanning electron microscope,identification with a microscopic infrared spectrometer,and evaluation of the risk characterization ratio were used to reveal the occurrence characteristics of microplastics,and conduct ecological risk assessment.The results showed that the microplastics abundance in the sediments ranged from 56.67 to 2240 n·kg-1(based on the dry weight),with an average abundance of 941.21 n·kg-1.There was a significant difference in the microplastics abundance among the sampling sites(p<0.05).Fibers were the predominant shapes of microplastics,showing various appearances with friction and damages on the surface.Microplastics with a particle size of 0.1～0.5 mm accounted for more than 50%,mainly transparent in color.The main polymers components were polypropylene(PP),polyethylene(PE)and polyamide(PA).The pollution load index(PLI)and risk characterization ratio(RCR)of microplastics in the study area were 1.19 and 79.69,respectively,indicating a moderate level of microplastics contamination with a medium ecological risk.This study could provide valuable insights for the pollution status and risk assessment of microplastics in the sediment of the upper reaches of the Han River.
upper Han Rivermicroplastics(MPs)sedimentscharacterizationrisk assessment
NETL
NSTL
万方数据
