Resilience of Floating Treatment Wetlands to Repeated Freeze-Thaw Cycles
Abstract
Floating treatment wetlands (FTWs), made of a matrix of recycled polyethylene terephthalate (PET) fibers, are currently being used as a method to reduce nutrient loading in lakes. The matrix encourages growth of biofilms, which uptake nutrients from the water. However, the usefulness of FTWs has only been assessed in areas where the lakes do not freeze over in the winter. Repeated freeze-thaw cycles were run on sections of the FTWs in a laboratory setting in order to test the resilience of the PET fibers over the FTWs' advertised fifteen-year lifespan. Preliminary findings suggest that the stresses caused by freezing and thawing of the surrounding water contribute to deterioration of the PET fibers, leading to production of microplastics. Estimations indicate that approximately 0.063% of a FTW's mass could be lost as microplastics over the course of its lifespan. Production of microplastics contributes to plastic pollution in the treatment water, possibly offsetting any nutrient remediation the FTWs perform.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2017
- Bibcode:
- 2017AGUFM.H41E1486O
- Keywords:
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- 1803 Anthropogenic effects;
- HYDROLOGY;
- 1834 Human impacts;
- HYDROLOGY;
- 1836 Hydrological cycles and budgets;
- HYDROLOGY;
- 1880 Water management;
- HYDROLOGY