Norflurazon and simazine removal from surface water using a constructed wetland

Area of Science:

• Environmental Science
• Agricultural Chemistry
• Water Treatment

Background:

• Norflurazon and simazine are common pre-emergent herbicides found in South Florida's agricultural water systems.
• These herbicides pose a risk to surface water quality and aquatic ecosystems.

Purpose of the Study:

• To evaluate the effectiveness of a constructed wetland in removing norflurazon and simazine from agricultural surface water.
• To understand the discharge patterns and removal efficiencies of these two herbicides in a wetland system.

Main Methods:

• A 1.34 ha constructed wetland with a flow rate of 740 L/min was used.
• Norflurazon and simazine were introduced into the wetland, and water samples were collected over 360 hours.
• Herbicides were extracted using C-18 cartridges and analyzed by GC-TSD.

Main Results:

• Norflurazon removal was 0%, with no distinct peak concentration observed during discharge.
• Simazine removal was 47.4%, with a discharge period of 58 hours.
• Detectable concentrations ranged from 3.9 μg L(-1) for norflurazon and 11.9 μg L(-1) for simazine.

Conclusions:

• The constructed wetland demonstrated negligible removal of norflurazon.
• The wetland showed moderate removal of simazine, but discharge patterns varied significantly.
• Further research is needed to optimize wetland design for effective removal of specific agricultural herbicides.