Competitive Sorption of Pesticides onto Treated Wood Charcoal and the Effect of Organic and Inorganic Parameters on Adsorption Capacity

This paper presents competitive sorption of coexisting pesticides onto treated wood charcoal and describes the effect of various water quality parameters, viz., pH, ionic strength, chloride concentration, presence of calcium and magnesium, fertilizers, humic acid, polyacrylic acid, and also the effect of coexisting pesticides on the sorption of endosulfan onto treated wood charcoal. The coexisting pesticides were found to hinder the performance of wood charcoal in removing endosulfan. Competitive uptake study revealed that endosulfan occupies more sites followed by atrazine and monocrotophos. Solubility in water could be one of the major reasons for this preferential order. The presence of humic acid was found to show much more significant influence on the performance of wood charcoal than the presence of polyacrylic acid. Among fertilizers, single superphosphate was found more influential. Most of it, among the other reasons, could be due to the competition of the coexisting molecules for the available adsorption sites on wood charcoal. Other parameters have resulted in some fluctuations in performance, but the effects are not significant. Endosulfan removal efficiency faltered at higher pH values, and ionic species did not affect the sorption as endosulfan is nonionic under neutral conditions