title: Adsorption and desorption characteristics of lindane, carbofuran and methyl parathion on various Indian soils.
abstract: Adsorption and desorption characteristics of three insecticides on four Indian soils were studied. Insecticides used were representative of organochlorine, organophosphate, and carbomate groups. The order of adsorption of pesticides on soils was: lindane>methyl parathion>carbofuran. Compost soil had shown the maximum adsorption capacity. The order of adsorption capacity of various soils were: compost soil>clayey soil>red soil>sandy soil. Adsorption isotherms were better fitted to Freundlich model and Kf values increased with increase in organic matter content of the soils. Thermodynamic parameters indicated favorable adsorption of all the three pesticides in four different soils. Adsorption was exothermic in nature. Distilled water desorbed 30-60% of adsorbed pesticides whereas; organic solvents were able to affect 50-80% of sorbed pesticides. Clay content and organic matter played a significant role in pesticide adsorption and desorption processes. Hysteresis effect was observed in red, clayey and compost soils. Hysteresis effect increased with increase in organic matter and clay content of the soils.
authors.affiliation: Department of Civil Engineering, Indian Institute of Technology Madras, Chennai 600036, India. ramakrishnaiitm@gmail.com
authors.forename: K
authors.initials: K
authors.lastname: Rama Krishna
authors.forename: Ligy
authors.initials: L
authors.lastname: Philip
mesh_terms: D000327:Adsorption; D000538:Aluminum Silicates / Q000032:analysis; D002235:Carbofuran / Q000032:analysis*; D000077215:Clay; D052918:Environmental Restoration and Remediation; D001556:Hexachlorocyclohexane / Q000032:analysis*; D006812:Humic Substances / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007194:India; D007306:Insecticides / Q000032:analysis*; D007700:Kinetics; D008743:Methyl Parathion / Q000032:analysis*; D012822:Silicon Dioxide / Q000032:analysis; D012987:Soil / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D000538:Aluminum Silicates; D006812:Humic Substances; D007306:Insecticides; D012987:Soil; D012989:Soil Pollutants; D008743:Methyl Parathion; D001556:Hexachlorocyclohexane; D012822:Silicon Dioxide; D002235:Carbofuran; D000077215:Clay