Aging microplastics and coupling of "microplastic-electric fields" can affect soil water-stable aggregates' stability

Area of Science:

• Environmental Science
• Soil Science
• Ecotoxicology

Background:

• Microplastic (MP) pollution is a growing global concern, with aged MPs accumulating in soil ecosystems.
• The impact of aged MPs on the stability of water-stable soil aggregates remains poorly understood.

Purpose of the Study:

• To investigate the influence of aged polystyrene and polypropylene microplastics on soil aggregate stability.
• To elucidate the mechanisms by which MPs affect soil structural units and bonding.

Main Methods:

• Analysis of aged polystyrene and polypropylene microplastics' effects on soil aggregate stability.
• Investigation of coupled effects of soil electric fields and MPs on aggregate stability.

Main Results:

• Aged MPs significantly affect soil organic matter and microorganisms, key components of soil aggregates.
• MPs reduce the structural stability of soil aggregates by disrupting particle bonding, impacting erosion resistance.
• The study identified a critical electric field intensity for aggregate explosive fragmentation under specific electrolyte concentrations.

Conclusions:

• Microplastics alter soil aggregate stability by affecting fundamental soil structural components.
• Understanding MP-soil interactions is crucial for assessing soil erosion and environmental risks.
• This research provides new insights into the mechanisms of MP impact on soil aggregate stability.