Effects of microplastics on the porosity and connectivity with different soil textures: Based on CT scanning

Abstract

Abstract Microplastics-contaminated soils exhibit disordered pore architecture. However, research on soil pores' morphological features and connectivity under microplastics endowment needs to be more extensive. This research used computed tomography and three-dimensional visualization tools to quantitatively analyze the micropore structure of sandy soils, sandy loam, and loamy soils after microplastics endowment, and we also built a pore network model. The findings revealed that microplastics deposition considerably altered the spatial structure of the pores and reduced soil porosity. The effects of microplastics accumulation on soil pore morphology and connectivity varied greatly between soil textures, with connected pores in sandy soils and sandy loams partially or completely disappearing and connected pores in loamy soils changing from a complex spatial structure to a monolayer sheet. Furthermore, as the abundance of microplastics increases, the soil pore network model becomes more straightforward, and the Euler number and tortuosity increase, which leads to the hydraulic conductivity declines. Finally, the microplastics endowment caused significant damage to the soil's connectivity and reduced its infiltration ability.