Mitigation of two pyrethroid insecticides in a Mississippi Delta constructed wetland.
Constructed wetlands are a suggested best management practice to help mitigate agricultural runoff before entering receiving aquatic ecosystems. A constructed wetland system (180 m x 30 m), comprising a sediment retention basin and two treatment cells, was used to determine the fate and transport of simulated runoff containing the pyrethroid insecticides lambda-cyhalothrin and cyfluthrin, as well as suspended sediment. Wetland water, sediment, and plant samples were collected spatially and temporally over 55 d. Results showed 49 and 76% of the study's measured lambda-cyhalothrin and cyfluthrin masses were associated with vegetation, respectively. Based on conservative effects concentrations for invertebrates and regression analyses of maximum observed wetland aqueous concentrations, a wetland length of 215 m x 30 m width would be required to adequately mitigate 1% pesticide runoff from a 14 ha contributing area. Results of this experiment can be used to model future design specifications for constructed wetland mitigation of pyrethroid insecticides.
Moore
M T
MT
USDA Agricultural Research Service National Sedimentation Laboratory, Water Quality and Ecology Research Unit, PO Box 1157, 598 McElroy Drive, Oxford, MS 38655, USA. matt.moore@ars.usda.gov
Cooper
C M
CM
Smith
S
S
Cullum
R F
RF
Knight
S S
SS
Locke
M A
MA
Bennett
E R
ER
D000383:Agriculture; D007306:Insecticides / Q000032:analysis; D008922:Mississippi; D009570:Nitriles / Q000032:analysis; D011722:Pyrethrins / Q000032:analysis; D011891:Rain; D014872:Water Movements; D014874:Water Pollutants, Chemical / Q000032:analysis; D018508:Water Purification / Q000379:methods*; D053833:Wetlands
D007306:Insecticides; D009570:Nitriles; D011722:Pyrethrins; D014874:Water Pollutants, Chemical; C052570:cyfluthrin; C037304:cyhalothrin