KINETICS AND ADSORPTION ISOTHERM MODELLING OF MERCURY ION USING ACTIVATED CARBON FROM PALM EMPTY FRUIT BUNCHES

Abstract

Research on kinetics and adsorption isotherm modelling of mercury with activated carbon from palm empty fruit bunches (EFB) has been performed. EFB carbon that has the best characteristics was that has prepared thermally at a temperature of 550^oC for 3 hours and activated by using 4 M NaOH as activator for 10 hours. The resulting activated carbon has ash content of 1.51%, water content of 1.74%, iodin number content 990.57 mg/g and a surface area of 792.43 m²/g. The studies show that adsorption capacity of optimum condition for Hg²⁺ adsorption were as the following: water pH = 6, with a mixing speed of 80 rpm for 120 minutes and the amount of adsorbent used was 0.5 g. The condition led to an adsorption effectivenees for about 94.66 %. Which has lowered the Hg²⁺ concentration from 1.31 x 10^-2 ppm to 7 x 10^-4 ppm. The model of adsorption kinetics followed a pseudo first order kinetics model with equations: log (qe "“ qt) = - 0.008t + 1.056. The value of adsorption rate constant (k₁) is 0.0184 min^-1. The model of adsorption isotherm followed a Freundlich isotherm model with equations:   ln (x/m) = 0.404 ln Ce "“ 1.208. The value of the adsorption capacity (K), equilibrium constant (n) and energy of adsorption (E) produced was 3.3469 mg/g; 2.4752 L/mg and 3.0432 kJ/mol..