Study On Microplastic Pollution Characteristics And Ecological Risk Assessment In Tacheng And Surrounding Areas

Microplastics,which are widely present in various environmental media,are an emerging environmental pollutant.There are many sources of microplastics,small size,light weight,easy to be swallowed by organisms,difficult to degrade in the natural environment,easy to move under the action of various external forces,and co-existing with other pollutants in the environment,which will have an immeasurable impact on the ecological environment,so it has attracted the exploration and research of many researchers.In recent years,the exploration of microplastic pollution in the water environment at home and abroad has focused on the marine environment,and the characteristics of microplastic pollution in the freshwater environment have been studied very little.The number one plastic producing country is China,but there is very little research data on the pollution of microplastics in the freshwater environment.In addition to this situation,because the specific surface area of microplastics is very large,they can become a medium in the environment to adsorb other types of pollutants,so they will affect the water environment and produce comprehensive pollution,thereby causing harm to the health and safety of the ecological environment.By exploring the composite pollution characteristics of microplastics and antibiotics in the environment,it has a very important reference value for in-depth understanding of the ecological and environmental risks of microplastics.For the current situation,the spatiotemporal distribution characteristics of microplastic pollution and the degree of ecological risk have not been further explored in China’s freshwater system,and the ecological risk caused by microplastics to the environment has not been accurately measured by the concentration of microplastics.Therefore,the thesis selected the freshwater system of Tacheng and its surrounding areas in Northwest China as the object for exploration,and preliminarily explored the temporal and spatial distribution characteristics of microplastic pollution in Tacheng and its surrounding areas in different seasons from qualitative and quantitative perspectives,and simulated in the laboratory to study the characteristics and potential impact mechanism of composite pollution of antibiotics and microplastics in the natural environment.At the same time,taking the freshwater system in and around Tacheng as an example,the potential ecological risks of microplastics were analyzed and estimated by using different assessment methods.The results of the exploration are as follows:(1)The abundance of microplastics in the freshwater system of Tacheng City ranged from 49±2-365±6 per L.The abundance of microplastics in freshwater systems around Tacheng ranged from 69±3-332±21 per L.The shape of microplastics is dominated by fibrous microplastics(86.2%).The size distribution of microplastics is between 0.1-1.0 mm(87.55%),and the colors are mainly black and white.Fourier infrared spectroscopy analysis showed that most of the particles we selected were microplastic particles,which are mainly composed of polyethylene(PE)and polyester(PET).The characteristics of microplastic pollution change with the seasons.This experiment provides a reference for understanding the exact pollution characteristics of microplastics in freshwater systems.(2)The concentration of PP on the surface of florfenicol when it reaches the equilibrium state is 1.36mg/g,and the concentration of PS when the adsorption on the surface of florfenicol reaches the equilibrium state is 0.54 mg/g,and the adsorption performance of florfenicol is much larger than that of PP.The absorption kinetic characteristics of florfenicol on polystyrene particles conform to the quasi-secondary kinetic mode(R2> 0.981),so the adsorbent particles are controlled by internal diffusion.Isothermal adsorption experiments show that compared with Freundlich model and Langmuir model,the Linear model can more accurately depict the isothermal adsorption of microplastics to florfenicol.(R2> 0.970).Compared with polystyrene,polypropylene has greater adsorption properties.(3)The size of the polymer toxicity fraction will affect the assessment results of the potential ecological risk method and the microplastic polymer composition index method,almost all sampling points are serious pollution,the degree of polymer pollution and the assessment index will change with seasonal changes,among which the largest degree of pollution is PVC and PAN.The results of the pollutant load index method show that the level of microplastic pollution in this region is low.The study uses the current research method of micro-plastic pollution at home and abroad to explore the pollution characteristics and distribution range of micro-plastic in the freshwater system in the Tacheng area.At the same time,the source of pollution of microplastics was analyzed based on its physical and chemical characteristics.The potential ecological risks of micro-plastic are evaluated based on different methods,and provided suggestions and data references for relevant decision makers.This study selected fluoropizko as a representative of antibiotics,and PP and PS,as the representative of typical micro-plastic,explore the characteristics and mechanisms of the adsorption behavior of micro-plastic on fluoropypinko and data reference.