| 引用本文: | 王志超,李嘉辰,张博文,等.基于CT扫描的微塑料对砂壤土孔隙结构的影响研究[J].灌溉排水学报,2023,42(9):79-86. |
| WANG Zhichao,LI Jiachen,ZHANG Bowen,et al.基于CT扫描的微塑料对砂壤土孔隙结构的影响研究[J].灌溉排水学报,2023,42(9):79-86. |
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| 摘要: |
| 【目的】探究微塑料对砂壤土孔隙结构的影响，为土壤新型污染物微塑料的防治提供科学依据，也对应用CT扫描进行土壤结构与土壤质量评估提供借鉴与指导。【方法】采用室内土柱模拟方法和计算机断层扫描技术，对CK（未赋存微塑料的空白组）和M（赋存2%浓度聚丙烯微塑料的试验组）处理进行了三维土壤孔隙结构的可视化分析和孔隙特征参数的测定。【结果】聚丙烯微塑料显著影响砂壤土孔隙结构。通过对三维孔隙结构可视化研究发现，CK中土壤孔隙分布较为均匀，出现明显下沉且纵向连续性强，而M处理中土壤孔隙破碎化程度高，连通性较差；且CK中土壤孔隙度为4.98%，M处理中土壤孔隙度只有3.79%。聚丙烯微塑料赋存条件下土壤孔隙数量与孔隙体积分布随土壤深度发生变化。在土柱0~4 cm深度范围内，土壤孔隙总数量表现为CK＞M处理，M处理中土壤孔隙总数较CK降低了73.02%，且二者的孔隙数量差异随土壤深度的增加而逐渐增大；土壤平均孔隙体积表现为CK（1 709 mm3）＞M处理（1 235 mm3），且相较于CK，M处理的大体积土壤孔隙数量占比有不同程度的降低。聚丙烯微塑料对砂壤土孔隙形态特征产生了影响。随着土层深度的增加，CK的孔隙成圆率趋于平稳，孔隙更接近圆形；但孔隙平均当量直径却表现为M处理＞CK，M处理的平均当量直径均随土壤深度的增加呈逐渐上升的趋势。【结论】聚丙烯微塑料的赋存影响了砂壤土孔隙结构并降低了土壤孔隙度，对土壤孔隙数量和形态特征也产生了一定的影响。 |
| 关键词: 计算机断层扫描技术；微塑料；土壤孔隙结构；三维可视化 |
| DOI：10.13522/j.cnki.ggps.2022541 |
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| Effect of Microplastics on Pore Structure of Sandy Loam Soil: Study Using X-ray Computed Tomography |
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WANG Zhichao, LI Jiachen, ZHANG Bowen, JING Shuangyi, LI Weiping
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College of Energy and Environment, Inner Mongolia University of Science and Technology/
Autonomous Region Collaborative Innovation Center for Ecological Protection and
Comprehensive Utilization of Inner Mongolia Section of the Yellow River Basin, Baotou 014010, China
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| Abstract: |
| 【Background】Microplastic particles are an emerging pollutant found in almost all ecosystems including soils. Its impact on soil function is multifactual, and this paper investigates the change in pore structure of soil contaminated by microplastic particles.【Method】Sandy loam soil samples with (treatment) and without (CK) contaminated by 2% of polypropylene microplastics were taken from different depths in soil columns. They were then scanned using x-ray Computed tomography. The pore structure in each sample was analyzed.【Result】The polypropylene microplastics significantly affected pore structure of the soil. 3D visualization revealed that the pores in the non-contaminated soil were more uniformly distributed and well connected compared to the contaminated soil. In contrast, pores in the contaminated soil were highly fragmented and less connected. The porosity of pores identified by the image was 4.98% and 3.79% for the CK and the treatment, respectively. The number of pores and distribution of pore volume varied with soil depths in soil column contaminated by microplastic particles. In the 0~4 cm soil layer, the total number of pores in the treatment was 73.02% lower than that in the CK. The difference in the number of pores between CK and the treatment increased gradually with the increase in soil depth. The average volume of pores in the CK and treatment was 1 709 mm3 and 1 235 mm3, respectively, with CK containing more large pores than the treatment. The microplastics also influenced the pore morphology in that with the increase in soil depth, the pore rounding rate in the CK tended to stabilize and the pores were close to round. The average equivalent diameter of the pores in the treatment was greater than that in the CK, and increased gradually with the increase in soil depth.【Conclusion】Polypropylene microplastics not only reduced the porosity of the sandy loam soil, it also affected the number and morphology of the pores at different soil depths. |
| Key words: computed tomography technique; microplastics; soil pore structure; three-dimensional visualization |
