海南乐东农用地土壤微塑料分布状况调查

Investigation on Microplastics Distribution of Soil in Ledong Farmland,Hainan

为掌握海南农用地土壤微塑料赋存含量与分布特征,通过现场监测和实验室分析相结合的研究方法,经密度浮选法进行样品前处理,采用傅立叶变换显微红外光谱仪对土壤微塑料样品分析测定,探讨了农用地不同农业种植区土壤微塑料分布状况及存在的潜在生态影响。结果表明,表层土壤微塑料丰度为366.67~3366.67个/kg,平均丰度为(1147.29±639.95)个/kg。微塑料成分以聚乙烯-丙烯共聚物(PE-PP)、聚乙烯(PE)占主导。研究区域土壤整体以1.0~2.0 mm微塑料为主,粒径组成趋向于小型化。此外,覆膜地块以蓝色碎片、蓝色薄膜、黑色薄膜塑料居多,未覆膜地块则以半透明的纤维塑料占主导。总体而言,乐东农用地微塑料丰度存在明显空间分布差异,覆膜地块丰度值高于无覆膜地块,丰度水平与地块种植方式密切相关。与国内外农田区域相比,乐东农用地微塑料丰度整体处于偏高水平。

To master storage capacity and distribution characteristics of soil microplastics with Hainan farmland,a combination of on-site monitoring and laboratory analysis was used by density floatation method,analysis and determination of soil microplastic were followed by using Fourier Transform Infrared(FTIR)microscope.Distribution of soil microplastics and the potential ecological effect in different agricultural planting areas were also discussed.Results revealed that microplastics abundance of topsoil were ranged from^(3)66.67 to 3366.67 ind/kg,with the mean value was(1147.29±639.95)ind/kg.Components of microplastics were dominated by polyethylene-propylene copolymer(PE-PP)and polyethylene(PE).Sizes of microplastics in the whole farmland were predominantly within the range of 1.0 to 2.0 mm,with a tendency towards smaller sizes.In terms of colors and shapes,the film-covered land were mostly composed of blue fragments,blue films,and black films,while non-film covered land were predominantly made of translucent fiber plastics.In general,there were significant differences in spatial distribution of microplastic abundance in Ledong farmland,its abundance of film-covered land was significantly higher than that of non-film covered land,which was closely associated with crop planting methods.Compared with domestic and foreign areas,microplastics abundance of Ledong farmland was relatively higher.