TR(BR)-7/99-2000 : Transportation behaviour of lindane in different types of soils

Abstract

The contamination of groundwater by pesticides is a worldwide problem because of their tissue degradation and carcinogenic in nature. The pesticides are bio-accumulative and stable and, therefore, require close monitoring. The pesticides used for agricultural, forestry and domestic activities are leaching into the groundwater. It is, therefore, very important to study the transportation behaviour of pesticides in different types of soil media. The lindane is used widely in India for a variety of purposes. Therefore, an attempt has been made to study the transportation behaviour of lindane in sandy and loamy soils.

The effect of various operating variables, viz., concentration of lindane, pH of the mobile phase, soil column length and flow rate have been studied. It has been observed that the concentration ranging from 5 to 25 and 5 to 35µg were retarded by the sandy and loamy soils respectively. Therefore, 40 µg was selected as the optimum concentration for the study. The pH was varied from 2 to 7 and it was found that the minimum transportation of lindane occurred at pH 7.0 in both sandy and loamy soils. The effect of column length on the transportation of lindane indicates that the amount of lindane transported decreases with increasing column length. The effect of flow rate did not show any significant effect on the transportation of lindane. The distribution of lindane was also studied under the saturated conditions. The uniform distribution of lindane (25.0 mL of 5.0 mg/L) has been observed after 240 hrs. and 12 weeks in sandy and loamy soils respectively.