Atrazine remediation in wetland microcosms

Laboratory wetland microcosms were used to study treatment of atrazine, in irrigation runoff by a field-scale-constructed wetland under controlled con ditions. Three experiments, in which 1 ppm atrazine was added to the water column of three wetland, one soil control, and one water control microcosm, were conducted. Atrazine dissipation from the water column and degradate f ormation (deethylatrazine [DEA]; deisopropylatrazine [DIA]; and hydroxyatra zine [HA]) were monitored. Atrazine dissipation from the water column of we tland microcosms was biphasic. Less than 12% of the atrazine applied to wet land microcosms remained in the water column on day 56. Atrazine degradates were observed in water and sediment, with HA the predominant degradate. An alysis of day 56 sediment samples indicated that a significant portion of t he initial application was detected as the parent compound and HA. Most pro bable number (MPN) assays demonstrated that atrazine degrader populations w ere small in wetland sediment. Wetland microcosms were able to reduce atraz ine concentration in the water column via sorption and degradation. Based o n results from this study, it is hypothesized that plant uptake contributed to atrazine dissipation from the water column.