K. Kumari

Influence of different factors on the adsorption of carbofuran (2,3-dihydro-2,2-dimethyl-7-benzofuranyl-N-methyl carbamate) on soils

The effects of exchangeable cations (H+ and Na+), autoclaving, organic matter, cationic and anionic surfactants, and temperature on the adsorption of carbofuran on two different types of soils were studied. The adsorption isotherms for all effects/treatments were in close agreement with the Freundlich equation and yielded S-shaped isotherms. The amount of carbofuran adsorbed in all cases was higher in Jhansi red loam soil than in Pilibhit sandy loam soil and was related to organic matter content, clay content, CaCO3 content, surface area, and cation-exchange capacity of the soils. The adsorption on soils from both sites follows the order H soil-->Na soil-->natural soil at 25 degrees C-->autoclaved soil-->soil from which organic matter had been removed-->cationic surfactant-->anionic surfactant-->natural soil at 50 degrees C and was in accordance with Freundlich constant K values and distribution coefficient Kd values. The adsorptive capacity of carbofuran for organic matter and clay content for both the Jhansi and the Pilibhit soils was also evaluated by calculating Kom and Kc values, and it was found that the carbofuran adsorption was better correlated with clay content than with organic matter content of soils. On the basis of adsorption isotherms, various thermodynamic parameters such as the thermodynamic equilibrium constant Ko, standard free energy (delta G zero) changes standard ethalpy (delta H zero) changes, and standard entropy (delta S zero) changes have been calculated in order to predict the nature of isotherms.

Sorption Thermodynamics of Cypermethrin at High Concentrations on Some Indian Soils

Abstract Sorption thermodynamics of cypermethrin on four different type of Indian soils (alluvial, forest, hill and humid) from water/acetone mixtures (fs = 0.666) at 30°C and 50°C has been investigated through sorption isotherms, Freundlich equation, distribution coefficient and thermodynamic parameters. The measured equilibrium sorption isotherm for all soil-cypermethrin combinations were of non-linear Freundlich type and yielded ‘S’ shaped curves for soils at both temperatures. The sorption of cypermethrin was higher on hill silt loam soil followed by forest loam, alluvial sandy loam and humid loam soils and lower at higher temperature. The order of sorption was anticipated with K and Kd values. Comparison of the Freundlich coefficient K-values in relation to soil properties suggests that organic carbon, CaCO3, clay content and surface area are the most important factors affecting cypermethrin sorption. From Freundlich sorption constant K values, the organic carbon partition coefficient Koc and clay co...

Effect of Different Factors on the Movement of Some Amino Acids in Soils Using Thin-Layer Chromatography

Abstract The influence of organic matter, CaCo3, saline and alkaline salts, flyash, exchangeable cations and pH on the mobility of monocarboxylic, dicarboxylic, basic and aromatic amino acids has been studied using soil thin-layer chromatographic technique in two different type of soils. The mobility was expressed in terms of Rf, RB, and RM values. The variation in Rf, RB and RM values of anino acids under different treatments have been reported and discussed on the basis of adsorption and leachability.

Adsorption thermodynamics of carbofuran on acid and base saturated soils

The adsorption of carbofuran on hydrogen, sodium, and calcium saturated soils has been studied at 25 and 50 degrees C. The adsorption data for all types of soils is in close agreement with Freundlich isotherms and yielded S-class isotherms. The maximum adsorption was observed in acid saturated soil. Therefore, it has been in accordance with the partial molal free energy changes (F) and Kd values. The adsorption has been lower at higher temperatures. The thermodynamic constant (KO), standard free energies (delta G degree), enthalpies (delta H degree), and entropy changes (delta S degree) have been calculated for predicting the nature of adsorption.

Movement of carbofuran (nematicide) in soil columns.

Adsorption and movement of carbofuran (a systemic nematicide) were studied using two Indian soils (clay loam and silt loam) of alluvial origin. Equilibrium adsorption coefficient (K) values measured using a batch-slurry technique follows the order clay loam greater than silt loam soil. The distribution coefficients (Kd) for both the soils in batch adsorption as well as in columns were also calculated. Carbofuran movement in soil columns during water infiltration in both air-dried and water-saturated columns was estimated. The order was as anticipated from K and Kd values. A larger amount of water was needed for leaching the carbofuran to 152 cm in clay loam soil than in silt loam soil. Carbofuran appears to increase in drier soils and in finer textured soils.

Paper Chromatography of 34 Organic Acids on Calcium Carbonate and Calcium Sulphate Impregnated Papers

Abstract Paper chromatographic separations of 34 organic acids on calcium carbonate and calcium sulphate impregnated paper has been developed. Tricarboxylic acids, dicarboxylic acids, amino acids, and keto acids and their derivatives can be separated in simple solvents such as acetone, ethanol, water, aqueous sodium chloride, ammonium chloride and calcium nitrate. Important separations achieved are: Adipic from maleic and malonic, cis-aconitic from I-cystine and nicotinic, citric or tartaric from ascorbic, gallic, malic and salicylic, I-aspartic from arginine-HCl, fumaric and glutamic, barbituric from hippuric and α-ketoglutaric, benzoic from ρ- & m-nitrobenzoic and cis-aconitic from trans-aconitic.

Electrophoretic Behaviour of 34 Organic Acids on Impregnated Strips

Abstract Electrophoretic behaviour of 34 organic acids on calcium sulphate impregnated papers has been studied. The 19 binary separations in aqueous sodium chloride and sodium sulphate solutions and distilled water have been achieved.

Influence of different factors on the adsorption of phosphamidon on soils

The effect of exchangeable cations (H+ and Na+), organic matter and temperature on the adsorption of phosphamidon on two different types of Indian soils was studied. The adsorption isotherms for all the effects/treatments were in close agreement with the Freundlich equation and yielded (S) shaped isotherms. The amount adsorbed in all the cases was lower in tarai loam soil than black silt clay loam soil and was related to organic matter content, clay content, CaCO3 content, surface area and CEC of the soils. The adsorption on both the soils follows the order as H‐soil > Na‐soil > natural soil at 25°C > natural soil at 50°C > organic matter removed soil. This order of adsorption was in accordance with Freundlich constant K values and distribution coefficient K d‐values. The adsorptive capacity of phosphamidon for organic matter and clay content for both the soils was. also evaluated by calculating Kom and Kc values and found that phosphamidon adsorption was slightly better correlated with clay content than ...

Movement of Phosphamidon in Soil Columns

Abstract Adsorption and movement of phosphamidon, a systemic non-ionic insecticide, was studied using two different types of Indian soil, clay loam and silt loam, of alluvial origin. Equilibrium adsorption coefficient, K, values determined by batch slurry technique were in the order: clay loam>silt loam. The distribution coefficient, Kd , for both soils in batch adsorption as well as in columns was also calculated. The phosphamidon movement measured in soil columns during water infiltration was in the order: silt loam > clay loam. This order was anticipated from the K and Kd values. A larger amount of water was needed for leaching the phosphamidon to 60 inches in clay loam than in silt loam soil.

Studies of thermodynamics of phosphomidon on fly ash

Adsorption thermodynamic studies of phosphomidon on fly ash at 25° and 50°C have been analysed as adsorption isotherms, Freundlich equations, Kd values and various other thermodynamic parameters. These data were in close agreement with Freundlich isotherms and yield ‘S’ type isotherms at both the temperatures. Thermodynamic constants (Ko) and standard free energy (ΔG°), enthalpy (ΔH°) and entropy changes (ΔS°) have been calculated for predicting the nature of adsorption.