Effectiveness of emergent and submergent aquatic plants in mitigating a nitrogen–permethrin mixture

Abstract

ABSTRACTHydraulically connected wetland microcosms (∼50 L) in series were used to test the effectiveness of varying combinations of two common aquatic vascular plants, parrot feather (Myriophyllum aquaticum) and cattail (Typha latifolia), for mitigating contamination from a mixture of nitrogen (ammonium nitrate) and permethrin. The upstream series included Myriophyllum only (M) and Typha only (T) while the combination upstream effluent into downstream series included Myriophyllum into Myriophyllum (M + M) and Typha into Myriophyllum (T + M). During flow, M into M + M more efficiently mitigated nitrogen than T into T + M. Post-flow, nitrogen removal efficiency was greater for T versus M and M + M versus T + M. Mean aqueous dissipation half-lives (t1/2) of NH4-N and NO3-N were more rapid in T than M treatments. Ammonium and nitrate t1/2 was highly correlated with aquatic plant above-ground shoot biomass. Permethrin mitigation efficiencies and t1/2 were not significantly affected by plant species either singly or in combination. Trans-permethrin t1/2 was moderately correlated with plant biomass, but not cis-permethrin t1/2. Results of this study indicate differences in aquatic plant species and flow path influence nitrogen removal but not permethrin. However, plant species appears less important than overall plant biomass in ascertaining aquatic plant effectiveness in mitigating a nitrogen–permethrin mixture.