Atrazine biotransformation in wetland sediment under different nutrient conditions‐i: Anaerobic

Abstract

Anaerobic biotransformation of atrazine under three different nutrient conditions, i.e., D.I water, wetland water, and basal salt media (BSM), was investigated with the sediment from a wetland receiving sugar mill wastewa‐ter in Louisiana. None of the well‐known metabolites and their hydroxy analogs, except hydroxyatrazine were detected in all sample reactors. About 50% of 10 mg/L of atrazine disappeared after 38 weeks of incubation from liquid and sediment phases of the sample reactors with D.I. water and wetland water. However, more than 25% of the disappeared atrazine still existed as hydroxyatrazine in those sample reactors. BSM substantially increased the removal rate of atrazine. Atrazine concentrations dropped to less than detectable level after 38 weeks of incubation in the sample reactors with BSM. However, the hydroxyatrazine level in liquid and sediment phases of the BSM reactors was still about 2.5 mg/L. BSM without (NH₄)₂SO₄ decreased the atrazine transformation rate.

Key words:

• Atrazine
• Anaerobic Biotransformation
• Wetland Sediment
• Nutrients