Adsorption-Desorption Mechanism of Synthesized Benzimidazole Based Fungicide 2-(3’-Pyridyl) on Selected Soil Minerals

Abstract

The adsorption and desorption phenomenon of synthesized Benzimidazole based fungicide, 2-(3’-pyridyl)benzimidazole (PyBlm), was investigated by batch equilibrium method. Four soil minerals were utilized for thesorption studies including; alumina, silica, muscovite and montmorillonite. Highest value of adsorption coefficient(Kd(ads)), obtained for montmorillonite mineral (Mx (Al, Fe, Mg4) Si8O20 (OH4)) was 2779 µg ml-1. Highest rate ofadsorption is attributable to its considerably large surface area of 628 m2g-1 and highest inter-lattice d-spacing, 10 Å.Highest desorption (Kd(des)) was also observed in montmorillonite mineral (21.45 µg ml-1). Montmorillonite thusdisplayed increased sorption capacity for PyBlm among all tested minerals. Hysteresis coefficient ranged from 0.58 to3. The results were statistically evaluated by using one-way analysis of variance (ANOVA). Furthermore, statisticalevaluation done with the help of Minitab 17 expressed the good fitting of the obtained results, which was shown bymeans of residual plots. Current research which suggests the variable adsorption and desorption of PyBlm expresses theprofound dependence of PyBlm interaction on the physicochemical characteristics of the selected minerals. Allminerals except montmorillonite expressing poor adsorption signifying the percolation of PyBlm through them towardsthe lower soil profiles. Results obtained in the present research show of that montmorillonite in firmly interacting withthe PyBlm molecules and thus alleviating the possibility of PyBlm percolation to lower soil profiles.