Adsorption and thermodynamic parameters of chlorantraniliprole and dinotefuran on clay loam soil with difference in particle size and pH

Ahmed F. El-Aswad, Maher I. Aly, Mohamed R. Fouad, Mohamed E. I. Badawy
  • Journal of Environmental Science and Health Part B, April 2019, Taylor & Francis
  • DOI: 10.1080/03601234.2019.1595893

What is it about?

The behavior of chlorantraniliprole (CAP) and dinotefuran (DNF) insecticides was investigated in clay loam soil, a common type of the Egyptian soil. Effect of temperature, pH and particle size of the soil on the adsorption process was studied. Adsorption isotherm by bulk soil and its constituents; humic acid (HA), clay, silt and sand fractions was measured using batch equilibration technique. The results showed that the adsorption of the insecticides tested was significantly affected by the temperature and was a spontaneous interfacial process in the soil. Freundlich model accurately predicted the adsorption behavior of both insecticides. The interaction between soil and insecticides was endothermic and the highest adsorption for CAP and DNF was obtained at pH 9. However, the effect of pH on the adsorption of DNF was lower than that of CAP. Sorption of CAP and DNF on HA fraction was significantly greater than on clay fraction and bulk soil. In addition, the adsorption was significantly increased with particle size decrease. It could be inferred that the adsorption of CAP and DNF on clay loam soil was physical in nature and greatly influenced by the soil components, pH and temperature.

Why is it important?

Pesticide dynamics in soil, fate and behaviour of pesticides in environment, adsorption and desorption, leaching, degradation, dissipation, pesticide analysis by HPLC and the side effect.

Perspectives

Mohamed Riad Fouad
Alexandria University

Adsorption of a wide range of CAP and DNF concentrations on bulk soil and its constituents, HA, clay, silt and sand fraction was investigated in 24-h batch equilibrium experiments. Adsorption isotherms were well described by the Freundlich model. The isotherms of CAP and DNF on bulk soil were classified as L-type and S-type, respectively. The highest KF value of CAP was obtained from adsorption on HA fraction while that of DNF was obtained from its adsorption on clay fraction. Adsorption on the soil was significantly influenced by temperature. Adsorption capacity and affinity decreased with increasing temperature. The thermodynamic parameters indicated that the adsorption in clay loam soil was spontaneous, physical and endothermic process. The highest adsorption of CAP and DNF in soil was obtained at pH 9. A positive correlation between adsorption of CAP or DNF and adsorbent particle-size was recorded. The adsorption of CAP and DNF was higher on HA and clay fractions than that on bulk soil. The difference in adsorption capacity and adsorption characteristics was also obtained. In general, this manuscript studied many factors affecting on the adsorption of pesticides on soil individually. In future, it would be studied the interaction between the affecting factors on the adsorption. Also, the structure-adsorption characteristics relationship could be considered in further study.

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http://dx.doi.org/10.1080/03601234.2019.1595893

The following have contributed to this page: Professor Mohamed E. I. Badawy and Mohamed Riad Fouad