Journal
WETLANDS
Volume 29, Issue 3, Pages 837-844Publisher
SPRINGER
DOI: 10.1672/08-42.1
Keywords
herbicide; bottom sediments; organic carbon content; prairie; sediment pH; temperature
Categories
Funding
- National Science & Engineering Research Council
Ask authors/readers for more resources
The herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) is among the most frequently detected pesticides in the water-column of surface waters in Canada. Bottom sediments (0 to 15 cm) were collected in 41 wetlands across the prairie region of Canada and analyzed for organic carbon content (OC), pH, and texture. Using batch equilibrium experiments at 5 and 25 degrees C, the herbicide sorption coefficient, Kd, was determined for 41 sediments, along with more comprehensive herbicide sorption and desorption isotherms for 7 of these 41 sediments. The 2,4-D Kd was positively correlated with OC and negatively correlated with sediment pH. A small (3%) significant increase in the 2,4-D Kd occurred when the temperature was at 25 degrees C rather than 5 degrees C. Desorption rates were faster for sediments with <= 2.4% OC and exhibited little or no hysteresis, compared to sediments with >= 5.9% OC that consistently exhibited hysteresis. We conclude that bottom sediments could serve as a source of 2,4-D to the water-column regardless of water temperature (5 to 25 degrees C). However, the potential for accumulation of 2,4-D in wetland sediments would be small because between 62 and 100% of the 2,4-D sorbed by sediments was released after 8 hours.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available