Detection of microplastics in soil by non-invasive imaging - Analyzing microplastic effects on soil properties and root-soil interaction

通过非侵入性成像检测土壤中的微塑料 - 分析微塑料对土壤性质和根系-土壤相互作用的影响

• 批准号: 516672636
• 负责人: Professor Dr. Sascha E. Oswald
• 金额: --
• 依托单位: Arbeitsgruppe Ökologie der Pflanzen
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/516672636?language=en
• 关键词: Detection; microplastics; soil; non; invasive

Soils around the world are increasingly polluted with anthropogenic contaminants such as microplastics. The continuous input of microplastics changes the conditions in the soil habitat and affects soil biota. However, our understanding of how microplastics alters the structure and functioning of soil is still very limited. It is unclear how microplastics affect processes in the rhizosphere and what risks this poses for plants. Various analytic methods have become available to study different aspects of microplastics in soil. However, all of these methods involve sampling or processing steps that destroy the integrity of the sample. Thus, essential information about the relationship of the distribution of microplastics in the sample and soil microstructure and hydraulics is inevitably lost. Recently, however, we have developed a non-invasive approach that can detect microplastics in sandy soil. Complementary neutron and X-ray tomography allows for detection of microplastic particles in the dry soil and simultaneous mapping of the 3D structure of soil matrix and pore space. In this project, the method will be tested, optimized, and then applied to develop a better mechanistic understanding of how microplastics of different sizes and shapes affect soil microstructure and properties. We will investigate the incorporation of microplastic fibers in soil aggregates and explore their possible effects. We will also study whether the presence of microplastics modify the conditions in the rhizosphere relevant for root growth and water uptake and track water movements in soil in the presence of different sizes, shapes of microplastics. To begin with, the resolution of the combined tomography will be optimized for detection of fine structures such as microplastic fibers and film fragments. The consideration of shape descriptors and the integration of machine learning will support the segmentation of microplastic particles by distinguishing them from soil organic matter. For a natural sandy soil, the influence of microplastic fibers on the formation and stability of soil aggregates is analyzed in an aggregation experiment using high-resolution dual-mode tomography. The next step is to study the rhizosphere of young maize and lupine plants growing in sandy soil containing microplastics of various shapes to determine local changes in root structure, soil matrix structure and water movement. Finally, we will use high-speed neutron tomography to capture the dynamic water infiltration patterns in soil columns in 3D, with and without root systems. Evaluation of the shape and propagation speed of infiltration fronts will provide new insights into whether and how soil wettability is affected by embedded microplastic particles. Implementation of the non-invasive analytical approach will provide unique insights into soil microstructure and hydraulics modified by microplastics and provide a better mechanistic understanding of their shape-mediated effects on sandy soil.

世界各地的土壤正日益受到微塑料等人为污染物的污染。微塑料的持续输入改变了土壤生境条件，影响了土壤生物群。然而，我们对微塑料如何改变土壤结构和功能的理解仍然非常有限。目前尚不清楚微塑料是如何影响根际过程的，也不清楚这给植物带来了什么风险。各种分析方法可以用于研究土壤中微塑料的不同方面。然而，所有这些方法都涉及到破坏样品完整性的采样或处理步骤。因此，关于微塑料在样品中的分布与土壤微观结构和水力学关系的重要信息不可避免地丢失。然而，最近，我们开发了一种非侵入性的方法，可以检测沙质土壤中的微塑料。互补中子和x射线断层扫描允许在干燥土壤中检测微塑性颗粒，并同时绘制土壤基质和孔隙空间的3D结构。在这个项目中，该方法将被测试、优化，然后应用于更好地理解不同尺寸和形状的微塑料如何影响土壤的微观结构和性质。我们将研究微塑料纤维在土壤团聚体中的掺入，并探讨其可能的影响。我们还将研究微塑料的存在是否会改变与根生长和水分吸收相关的根际条件，并在不同大小、形状的微塑料存在下跟踪土壤中的水分运动。首先，组合层析成像的分辨率将优化，以检测微塑料纤维和薄膜碎片等精细结构。形状描述符的考虑和机器学习的集成将通过将微塑料颗粒与土壤有机质区分开来来支持微塑料颗粒的分割。采用高分辨率双模层析成像技术，研究了微塑性纤维对天然砂土团聚体形成和稳定性的影响。下一步将研究生长在含有不同形状微塑料的沙质土壤中的玉米和羽扇豆幼苗的根际，以确定根系结构、土壤基质结构和水分运动的局部变化。最后，我们将使用高速中子层析成像技术，在有和没有根系的情况下，以3D方式捕捉土壤柱中的动态水渗透模式。对渗透锋的形状和传播速度的评估将为土壤润湿性是否以及如何受到嵌入的微塑料颗粒的影响提供新的见解。非侵入性分析方法的实施将为微塑料修饰的土壤微观结构和水力学提供独特的见解，并为其对沙土的形状介导效应提供更好的机制理解。