Microplastic retention within infiltration basins used for managed aquifer recharge: Effectiveness and key controlling factors.

Infiltration media in aquifer recharge basins reduce microplastic concentrations by 70% from surface to deep sediments, demonstrating significant retention effectiveness.

• Why it matters: Protecting groundwater from emerging pollutants like microplastics is crucial amid increasing water demands and climate change, yet their retention in recharge systems remains underexplored.
• What they did: Researchers analyzed sediments from 11 infiltration basins, measuring microplastic abundance, size, polymer type, and sediment characteristics across different depths, alongside basin management data.
• The result: Microplastic concentration mainly depends on sediment depth and hydrological factors, with local sources influencing polymer types at the surface, emphasizing the water-sediment interface's role in safeguarding groundwater.