Uptake of C¹⁴-atrazine by prairie grasses in a phytoremediation setting

ABSTRACT

Agrochemicals significantly contribute to environmental pollution. In the USA, atrazine is a widely used pesticide and commonly found in rivers, water systems, and rural wells. Phytoremediation can be a cost-effective means of removing pesticides from soil. The objective of this project was to investigate the ability of prairie grasses to remove atrazine. ¹⁴C-labeled atrazine was added to sterilized sand and water/nutrient cultures, and the analysis was performed after 21 days. Switchgrass and big bluestem were promising species for phytoremediation, taking up about 40% of the applied [¹⁴C] in liquid hydroponic cultures, and between 20% and 33% in sand cultures. Yellow Indiangrass showed low resistance to atrazine toxicity and low uptake of [¹⁴C] atrazine in liquid hydroponic cultures. Atrazine degradation increased progressively from sand to roots and leaves. Most atrazine taken up by prairie grasses from sand culture was degraded to metabolites, which accounted for 60–80% of [¹⁴C] detected in leaves. Deisopropylatrazine (DIA) was the main metabolite detected in sand and roots, whereas in leaves further metabolism took place, forming increased amounts of didealkylatrazine (DDA) and an unidentified metabolite. In conclusion, prairie grasses achieved high atrazine removal and degradation, showing a high potential for phytoremediation.

KEYWORDS:

• Atrazine
• degradation
• pesticide
• metabolites
• remediation

Funding

Partial funding of the project was provided by the Center for Health Effects of Environmental Contamination at the University of Iowa, (Iowa City, Iowa). Radiolabeled atrazine and analytical standards of atrazine metabolites were provided in kind by Syngenta (Greensboro, NC, USA). This article is a publication of the Iowa Agriculture and Home Economics Experiment Station, Project 5075.