| Popis: |
The prevalence of microplastic (MP), typically characterised as polymeric materials of particle (1 µm - 5 mm) are an increasing concern in our marine and freshwater systems. International research efforts have mainly focused on the abundance, characteristics and implications of plastic pollution in marine settings, with the transport and fate of plastics in terrestrial and freshwater systems being less well understood. The pathway from land to sea is significant in the Irish context given the widespread use of MP rich biosolids for soil conditioning in agricultural lands. Biosolids represent the treated sewage sludge produced in the wastewater treatment process, ~80% of which nationally is used in land treatment. Given the combined nature (storm and foul water conveyed and treated together) of the drainage network in many parts of Ireland, coupled with evidence that 90% of MPs in influent waters are retained in these sewage sludges, the application of sludges to agricultural lands represents a considerable MP input on these land systems. MPs can potentially be moved or transported from these terrestrial systems through atmospheric escape, and in hydrological pathways through the soil matrix and/ or in direct overland runoff.Here we report on an experimental investigation exploring the transport potential of biosolid MPs through infiltration and percolation processes in agricultural fields. A drainage experiment was initially undertaken in loosely packed vertical sand columns. Polymers of different type (PVC, PET and LDPE), size ( |
