四川广元植烟土壤微塑料分布状况分析

【目的】为明确植烟土壤微塑料分布特征，解决微塑料污染的环境问题。【方法】以四川省广元市剑阁县汉阳镇植烟土壤为研究对象，采集25个调查点的土壤样品，采用密度浮选法提取土壤微塑料，通过体式显微镜观察土壤样品中微塑料丰度、面积、颜色、类型和粒径。【结果】广元烟田土壤微塑料丰度范围在1.20×10²～8.9×10² pieces·kg^-1，平均丰度为(4.81±3.53)×10² pieces·kg^-1，平均面积为(4.45±4.98)×10² mm²·kg^-1；土壤中主要存在4种类型的微塑料，分别是薄膜、碎片、泡沫、纤维，占比最多的为薄膜类；颜色存在黑色和透明，绝大部分以透明状态存在。薄膜、碎片、泡沫、纤维类微塑料的粒径平均值分别为1.18、1.12、1.69和2.14 mm。土壤微塑料粒径为0-0.5)、0.5-1)、1-2)和2-5) mm的分别占微塑料总数的5.59%、28.28%、48.41%和17.7...

Distribution of micro plastics in tobacco planting soil in Guangyuan,Sichuan Province

  Objective  This study aims to clarify the distribution of microplastics in tobacco-growing soils and solve the environmental problem of microplastics pollution.  Methods  The tobacco planting soil in Jiange Hanyang Town, Guangyuan City, Sichuan Province were taken as the research object, the soil samples were collected from 25 survey sites. The microplastics were extracted from soil using density flotation method, and the abundance, area, color, type and particle size of soil microplastics were observed with stereomicroscope.  Results  The research results showed that the abundance of soil microplastics in Guangyuan tobacco field ranged from 1.20×102~8.9×102 pieces·kg-1, the average abundance was (4.81±3.53)×102 pieces·kg-1, and the average area was (4.45±4.98)×102 mm2·kg-1. There were four types of microplastics in those soil samples including film, debris, foam and fiber, and film accounts for the most. Colors exist in black and transparent, and most of them exist in a transparent state. The average particle size of film, debris, foam and fiber was 1.18, 1.12, 1.69 and 2.14 mm, respectively. The soil microplastics with particle sizes of 0-0.5), 0.5-1), 1-2) and 2-5) mm accounted for 5.59%, 28.28%, 48.41% and 17.72% of the total microplastics, respectively. The area of microplastics in 0-1) mm2·piece-1 accounted for 19.05% of the total area of microplastics.The proportion of microplastic area to total area in this group was significantly lower than the proportion of microplastic quantity to total number (70.32%), and microplastics with small area in the soil sample accounted for a large proportion. The microplastic area ranging from0-1) mm2·piece-1accounted for 19.05%, which was significantly lower than the abundance of microplastics in the corresponding range (70.32%). The amount of microplastics in the sample soil increased with the decrease of area.  Conclusion  The partical size of soil microplastics in tobacco-planting fields in Guangyuan is mostly in the range of 0.5-2) mm, and most of them exist in the state of transparent film. The amount of microplastics increases with the decrease of its area. The use of plastic film during previous crop planting will increase the abundance of soil microplastics. This study reveals the occurrence characteristics of soil microplastics in tobacco-planting fields of Guangyuan, and provides basic data support for the prevention and control of soil micro plastics pollution in tobacco field.