| 引用本文: | 杨振浩,才 璐,李宗遥,等.微塑料种类和粒径对土壤水分入渗的影响[J].灌溉排水学报,2026,45(3):75-81. |
| YANG Zhenhao,CAI Lu,LI Zongyao,et al.微塑料种类和粒径对土壤水分入渗的影响[J].灌溉排水学报,2026,45(3):75-81. |
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| 摘要: |
| 【目的】探究微塑料种类和粒径对土壤水分入渗的影响。【方法】采用定水头土柱入渗试验，研究聚乙烯（PE）、聚丙烯（PP）、聚氯乙烯（PVC）的5种粒径（0.05、0.5、1、2、4 mm）微塑料污染对土壤水分入渗湿润锋、累积入渗量、累积入渗率和土壤含水率的影响。【结果】当湿润锋达到60 cm时，3种微塑料处理组所用时间均随着粒径的增大呈先增大后减小的变化特征。对于不同微塑料，粒径＜2 mm的PE处理组所用时间＜CK，粒径＞2 mm的处理组所用时间＞CK；PP处理组所用时间均＞CK；而PVC处理组所用时间均＜CK。3种微塑料均增大了累积入渗量，但增量较小，且各粒径间无显著差异。3种微塑料处理均增大了土壤含水率的垂直差异，浅层土壤含水率升高，深层降低。3种微塑料处理前期累积入渗率均高于CK，而后期接近CK。【结论】PVC、PE、PP的疏水性依次增大，疏水性越大，水分在土壤中的运移速率越慢。微塑料改变了孔隙结构与基质势，使入渗路径更为复杂，从而增大了累积入渗量与土壤含水率的垂直差异。 |
| 关键词: 聚乙烯；聚丙烯；湿润锋；土壤含水率 |
| DOI：10.13522/j.cnki.ggps.2024356 |
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| Effects of microplastic types and particle sizes on soil water infiltration |
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YANG Zhenhao, CAI Lu, LI Zongyao, LIU Zihan, HAN Jianqiao
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Northwest A&F University, Yangling 712100, China
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| Abstract: |
| 【Objective】Microplastic pollution has become a pervasive environmental concern. Increasing evidence has shown that microplastics can alter soil physical properties and hydrological processes. This study aims to elucidate the effects of different microplastic types and particle sizes on water infiltration in soil.【Method】Column experiments were conducted using soils amended with three common microplastic types: polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC). Microplastic particle sizes ranged from 0.05 to 4 mm; columns packed with unamended soil served as the control (CK). The effects of microplastics on the infiltration process were assessed by comparing wetting front migration, cumulative infiltration, infiltration rate and spatial variations in soil water content among different treatments.【Result】For all microplastic types, the time required for the wetting front to reach the depth of 60 cm initially increased and then decreased with increasing particle size. In PE-amended soils, infiltration was faster than that in CK when particle sizes were smaller than 2 mm, but became slower when particle sizes exceeded 2 mm. In contrast, water infiltration in PP-amended soils was consistently slower than that in CK, while infiltration in PVC-amended soils was generally faster than that in CK. Although microplastic addition slightly increased cumulative infiltration, differences among particle size treatments were not statistically significant. Microplastic amendments enhanced the heterogeneity of soil water distribution, increasing water content in the shallow layer while decreasing it in the deep layer relative to CK. During the early stage of infiltration, cumulative infiltration rates in microplastic-amended soils were higher than those in CK; however, these rates gradually converged toward the control values at the later stage.【Conclusion】Hydrophobicity of the microplastics followed the order PVC＜PE＜PP; water infiltration in soil decreased with increasing microplastic hydrophobicity. Microplastic incorporation alters soil pore structure and matrix potential, leading to more complex infiltration dynamics. |
| Key words: polyethylene; polypropylene; wetting front; soil moisture content |
