The interaction of some pesticides and herbicides with humic substances

Excess of Solubilization and Curvature in Nonionic Microemulsions

“…This relationship obtained only from the packing of the solute molecule as a wedge in the film is similar to that obtained experimentally [7]. This suggests that lindane acts like a wedge penetrating the hydrophobic chains.…”

“…This suggests that lindane acts like a wedge penetrating the hydrophobic chains. We do not consider the adsorption/desorption of the oil at the interface; this probably explains the difference between relationship [12] and the relationship [7] obtained experimentally.…”

“…This comparison illustrates the generality of the curvature variation induced by a hydrophobic solute: We see that the experimental value obtained in the Winsor I sample is close to the experimental points obtained in bicontinuous microemulsions, following Eq. [7].…”

Interactions Between Ionic Pesticides and Model Systems for Soil Fractions

“…Humic substances constitute the largest fraction of natural organic matter, and therefore may be used as reference materials to elucidate the mechanism of interaction between ionic herbicides and SOM (Hesketh et al, 1996). The classical view (Stevenson, 1994) states that humic substances are polydisperse mixtures, and that their chemical behaviour is generally determined by two types of functional groups: carboxylic and phenolic groups.…”

Prometrine–Humic Acids Interactions Studied at a Water/1,2‐Dichloroethane Interface

“…Organic pollutants, such as pesticides, can exist in dissolved state or in association with the colloidal phase, or adsorbed by the soil. The driving forces of this adsorption involve electrostatic interactions, hydrogen bond, charge transfer, acceptor -donor mechanisms, van der Waals forces and hydrophobic interactions [8]. These mechanisms operate simultaneously and their competition determines the retention of pesticides in soil and aquatic systems.…”