REMOVAL OF METHYL VIOLET FROM WATER BY SUNFLOWER SEED PEEL WITH ADSORPTION METHOD AND DETERMINATION OF ELECTRICAL FIELD EFFECT ON ADSORPTION

摘要

The removal of methyl violets from water by using sunflower seed peel as adsorbing agent was determined. Effect of pH, adsorbent dose, initial concentration and electrical field application were investigated. The adsorption efficiency was found to be about 99%, in case of pH = 7, initial concentration = 50 mg/l and adsorbent dose = 0.5 g. Applied electrical field of 300 V/m had a considerable effect on adsorption at pH 2, but not a significant role above this value. Kinetic studies showed that the process of adsorption of methyl violet to sunflower seed peel followed the pseudo-second order kinetic model. The values of rate constants indicated that adsorption was controlled by both pseudo-second order kinetics and intra-particle diffusion mechanism, but mainly by pseudo-second order kinetics. The equilibrium nature of methyl violet adsorption to sunflower seed peel has been described by Freundlich isotherms, but also thermodynamic parameters like free energy, entropy and enthalpy changes for the adsorption of methyl violet have been found and discussed.