Adsorption and Desorption Behavior of Chlorotriazine Herbicides in the Agricultural Soils

Abstract

The chlorotriazine herbicides have been applied worldwide for controlling of broadleaf weeds. These herbicides are known carcinogen and thus, their occurrence in surface and ground water is a cause of concern. In the present study, adsorption-desorption behavior of chlorotriazine herbicides namely simazine and atrazine was investigated. For the study, two different types of agricultural soil A (loam, 13.7% organic matter content) and soil B (clay-loam, 4.8% organic matter content) was collected from Punjab, India. The adsorption-desorption study was carried out by batch equilibration procedure. The data fitted well into the Freundlich equation. The adsorption K f values indicated that the simazine has more soil adsorption ability than atrazine. The extent of herbicides adsorbed to the soil was more under low pH conditions and decreased with the increase in pH value. Increase in temperature decreased herbicides adsorption ability for both the soil types. The Gibb's free energy (∆G) values were found less negative with the increase in temperature. Atrazine exhibited better desorption behavior than simazine. Soil A with high organic matter content exhibited sorption-desorption hysteresis. The results indicate that the soil organic matter content and aqueous solubility play an important role in the adsorption-desorption behavior of chlorotriazine herbicides. The present understanding of chlorotriazine herbicides sorption-desorption process will help to determine the herbicides fate and availability in soil, biodegradation, runoff and leaching.

Organophosphate Residue in Different Land Use in Mojogedang Karanganyar Central Java Indonesia

“…6; temperature (Tabassum et al, 2012). Singh and Cameotra (2013) adds, high soil temperatures increase evaporation due to increased solubility of pesticide residues in soil (Aktar et al, 2009). …”

Spinosad Adsorption on Humic and Clay Constituents of Lacustrine Egyptian Soils and Its Leaching Potential

“…The calculated Values of 1/n des ( The hysteresis coefficient (H) compares the strength of desorption and adsorption processes (Kumar and Singh, 2013). Calculated H values were 0.68, 0.90, and 0.85 for Abis soil, HA and clay fractions, respectively.…”

“…The equilibrium time was determined according to the adsorption kinetics study and previous studies of the spinosad adsorption (Thompson et al, 2002;Hui-jun et al, 2013;Singh and Cameotra, 2013). Batch adsorption kinetics experiment was carried out in 25-mL polypropylene centrifuge tubes at an initial spinosad concentration of 10 mg l -1 prepared in a background of 0.01M CaCl 2 .…”

“…The hysteresis coefficient, H, was calculated as H= (1/n des )/( 1/n ads ) according to Kumar and Singh (2013).…”

“…Previous studies suggested that adsorption of herbicide to the soil is the key process that affects their ecotoxicological impact, environmental mobility and the rate of degradation (Singh et al, 2004;Liu et al, 2010;Singh and Cameotra, 2013;). The desorption process of herbicides is also important since it determines the release rate and the potential mobility of herbicides in the soil (Liu et al, 2010).…”