Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4389356 | Ecological Engineering | 2014 | 5 Pages |
•Atrazine biodegradation in the Olentangy wetland was investigated with biometers.•Suspended solids in river water were concentrated in order to detect atrazine mineralization.•Atrazine mineralization was demonstrated in wetland sediment samples.•Mineralization was also tested with anaerobic electron acceptors NO3−, Fe(III) and SO42−.•Mineralization of atrazine was slower under anaerobic vs. aerobic conditions.
The purpose of this study was to assess the role of anaerobic electron acceptors in the biomineralization of atrazine in an established constructed wetland receiving seasonal fluxes of atrazine runoff from an agricultural watershed. The Olentangy River wetland receives river water with a hydraulic residence of about 36 h depending on hydrological conditions. Both sediment samples and suspended solids in the water were of interest in this study. Surface water was collected from the Olentangy River by grab sampling. Samples of sediment top sections were taken from the inlet, middle section, and outlet and combined to a composite for laboratory experiments. Atrazine mineralization in water and sediment samples was based on 14CO2 release from [U-ring-14C]-atrazine in biometer enclosures. The half-lives of atrazine mineralization by suspended solids in water ranged from 10 months to 5 years depending on incubation conditions. Sediment samples from the wetland showed considerable variation in the extent of mineralization, shortest half-life of about 7 days and the longest of about 6–7 weeks with or without an anaerobic electron acceptor. The results indicate that trace levels of atrazine entering wetland will likely persist for extended periods, often exceeding the hydrologic residence time of the wetland.