Effects of SOM, surfactant and pH on the sorption-desorption and mobility of prometryne in soils.
Sorption and desorption of the herbicide prometryne in two types of soil subjected to the changes of pH and soil organic matter and surfactant were investigated. The sorption and desorption isotherms were expressed by the Freundlich equation. Freundlich K(f) and n values indicate that soil organic matter was the major factor affecting prometryne behavior in the test soils. We also quantified the prometryne sorption and desorption behavior in soils, which arose from the application of Triton X-100 (TX100), a nonionic surfactant and change in pH. Application of TX100 led to a general decrease in prometryne sorption to the soils and an increase in desorption from the soils when applied in dosages of the critical micella concentration (CMC) 0.5, 1 and 2. At the concentration below the CMC, the non-ionic surfactant showed a tendency to decrease prometryne sorption and desorption. It appeared that TX100 dosages above CMC were required to effectively mobilize prometryne. Results indicate that the maximum prometryne sorption and minimum prometryne desorption in soils were achieved when the solution pH was near its pK(a). Finally, the influence of TX100 on the mobility of prometryne in soils using soil thin-layer chromatography was examined.
Cao
Jun
J
Department of Applied Chemistry, College of Science, Nanjing Agricultural University, Nanjing 210095, China.
Guo
Hua
H
Zhu
Hong Mei
HM
Jiang
Lei
L
Yang
Hong
H
D000327:Adsorption; D002855:Chromatography, Thin Layer; D006540:Herbicides / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D017830:Octoxynol / Q000737:chemistry*; D011400:Prometryne / Q000737:chemistry*; D012989:Soil Pollutants / Q000737:chemistry*; D013501:Surface-Active Agents / Q000737:chemistry*
D006540:Herbicides; D012989:Soil Pollutants; D013501:Surface-Active Agents; D011400:Prometryne; D017830:Octoxynol; D006861:Hydrogen Peroxide