Zhou Yuze, Dou Ming, Zhang Yan, Ning Kaizi, Li Yuxuan
School of Water Conservancy Engineering, Zhengzhou University, Zhengzhou, China.
School of Ecology and Environment, Zhengzhou University, Zhengzhou, China.
Environ Sci Process Impacts. 2024 Sep 18;26(9):1556-1570. doi: 10.1039/d4em00242c.
Microplastic (MPs) pollution has become a global issue, with particular concern regarding MPs in soil. To determine the characteristics of MPs in agricultural production areas and their impact on soil physicochemical properties, soil samples were collected from different land use types in the North China Plain. Layered sampling was conducted and the soil physicochemical properties were determined. A novel image recognition method based on fluorescence staining was proposed for the batch analysis of MPs in the study area. Together with the results of the soil physicochemical properties, the impact of MPs on soil physicochemical properties was analyzed and evaluated. The results showed that the soil MPs abundance in this agricultural area was moderate to low compared to other agricultural areas, with a larger proportion of particle-type and fragment-type MPs smaller than 10 μm. The soil MPs were predominantly composed of polyvinyl chloride (PVC) and polypropylene (PP). MPs abundance was higher in farmland and forest land than in vegetable fields. The impact of MPs on soil physicochemical properties was mainly manifested in the changes in soil structure due to the different MPs characteristics. Apart from abundance, the type of MPs was found to be the main factor affecting soil bulk density, with particle size and shape influencing the soil aggregate structure. MPs may effect the pH values of sandy and loamy soils, primarily by altering the soil porosity and water holding capacity, but also by increasing the area and duration of contact between the soil medium and external water sources. This study revealed the MPs characteristics in agricultural areas as well as the pathways by which they can impact soil physicochemical properties.
微塑料（MPs）污染已成为一个全球性问题，土壤中的微塑料尤其令人担忧。为了确定农业生产区微塑料的特征及其对土壤理化性质的影响，在中国华北平原不同土地利用类型中采集了土壤样本。进行了分层采样并测定了土壤理化性质。本研究提出了一种基于荧光染色的新型图像识别方法，用于对研究区域内的微塑料进行批量分析。结合土壤理化性质的结果，分析和评估了微塑料对土壤理化性质的影响。结果表明，与其他农业区域相比，该农业区域土壤微塑料丰度为中低水平，粒径小于10μm的颗粒型和碎片型微塑料占比更大。土壤微塑料主要由聚氯乙烯（PVC）和聚丙烯（PP）组成。农田和林地的微塑料丰度高于菜地。微塑料对土壤理化性质的影响主要体现在因微塑料特性不同而导致的土壤结构变化上。除丰度外，微塑料类型是影响土壤容重的主要因素，粒径和形状则影响土壤团聚体结构。微塑料可能会影响砂土和壤土的pH值，主要是通过改变土壤孔隙度和持水能力，还通过增加土壤介质与外部水源的接触面积和时间。本研究揭示了农业区域微塑料的特征以及它们影响土壤理化性质的途径。
