Studies of the adsorption thermodynamics of oxamyl on fly ash

Abstract

The adsorption thermodynamics of oxamyl on fly ash at 10°C, 25°C and 50°C have been studied via the relevant adsorption isotherms, Freundlich constants (KF and 1/n), distribution coefficient (Kc) and other thermodynamic parameters. The data were well fitted by the Freundlich equation (r2 > 0.98) and yielded S-shaped isotherms at all the temperatures studied. Thermodynamic parameters such as the thermodynamic equilibrium constant (Ko), the standard free energy change (ΔGo), the standard enthalpy change (ΔHo) and the standard entropy change (ΔSo) have been calculated as a means of predicting the nature of the adsorption process.