SUMMARY
In the present studies the adsorption efficiency of peach nut shells for the removal of endosulfan from aqueous solutions has been investigated. The adsorption of endosulfan has been studied as a function of contact time, concentration and temperature. Maximum adsorption (95 – 1%) was achieved for 0.24 10-4 mol dm-3 of endosulfan solution, using 0.1 g of adsorbent in 20 ml of solution for 30 min agitation time at pH 6. The Freundlich and Langmuir isotherms fit the equilibrium data satisfactory and their constants, sorption intensity 1/n (0.36), multilayer sorption capacity Cm 6.5 – 0.26 mmol g-1, and monolayer sorption capacity Q 0.27 – 0.03 mmol g-1, have been evaluated.Thermodynamics parameters namely change in enthalpy ?H, Gibbs free energy ?G and entropy ?S, were calculated. The negative values of ?G and positive value of ?H indicate that the adsorption process is spontaneous and endothermic in nature and positive value of entropy ?S confirms the possibility of favorable adsorption. The developed adsorption method has been employed to surface water samples.