Influence of surfactants on the leaching of bentazone in a sandy loam soil.
BACKGROUND
Surfactants are very often used for more efficient pesticide spraying, but knowledge about their influence on the leaching potential for pesticides is very limited. In the present study, the leaching of the herbicide bentazone [3-isopropyl-1H-2, 1,3-benzothiadiazin-4(3H)-one 2,2-dioxide] was measured in columns with sandy loam soil with or without the addition of a non-ionic surfactant, octylphenol ethylene oxide condensate (Triton X-100, Triton), and an anionic surfactant, sodium dodecylbenzenesulfonate (SDBS), and in the presence of both surfactants (SDBS + Triton).


RESULTS
The mobility of bentazone (B) increased in the following order: B + Triton (slowest) < B + SDBS + Triton < B < B + SDBS (fastest). When Triton X-100 was applied to the soil together with bentazone, the leaching of bentazone in the soil decreased significantly compared with leaching of bentazone without the addition of surfactant. SDBS and Triton X-100 neutralised their influence on the leaching speed of bentazone in the soil columns when both surfactants were applied with bentazone.


CONCLUSIONS
From the study it can be concluded that, depending on their properties, surfactants can enhance or reduce the mobility of bentazone. By choosing a non-ionic surfactant, bentazone mobility can be reduced, giving time for degradation and thereby reducing the risk of groundwater pollution.
Hua
Rimao
R
Key Lab of Agri-Food Safety of Anhui Province, College of Resource and Environmental Science, Anhui Agricultural University, 230036 Hefei, China.
Spliid
Niels H
NH
Heinrichson
Kirsten
K
Laursen
Bente
B
D000327:Adsorption / Q000187:drug effects; D001557:Benzenesulfonates / Q000494:pharmacology; D001581:Benzothiadiazines / Q000032:analysis* / Q000737:chemistry*; D006540:Herbicides / Q000737:chemistry; D009038:Motion; D017830:Octoxynol / Q000494:pharmacology; D012822:Silicon Dioxide / Q000737:chemistry*; D012987:Soil / Q000032:analysis*; D012995:Solubility; D013501:Surface-Active Agents / Q000494:pharmacology*
D001557:Benzenesulfonates; D001581:Benzothiadiazines; D006540:Herbicides; D012987:Soil; D013501:Surface-Active Agents; C001114:dodecylbenzenesulfonic acid; D012822:Silicon Dioxide; D017830:Octoxynol; C002003:bentazone