ACTIVATED CARBON SYNTHESISED FROM BOTTOM ASH FROM COAL FIRED BOILERS BY KOH ACTIVATION FOR LIQUID PHASE ADSORPTIONMUSONZA, L. MANDIPA, DUBE, DONATUS, SIBALI, L. LINDA, TUMISANG SEODIGENG AND CHIRIRIWA, HARRYAbstract The potential use of bottom ash activated with potassium hydroxide in liquid phase adsorption was studied. Proximity analysis, iodine value and batch experiments were used to characterize activated carbon. In order to perceive the mechanism of adsorption, experimental data was fitted to Freundlich, Langmuir, Temkin and Dubinin-Radushkevich adsorption isotherm models, and the coefficients of correlation were calculated to be 0.8092, 0.5936, 0.8865 and 0.5031. The kinetic data is fitted with pseudo first, second order together with models involving intraparticle diffusion. The pseudo second order rate constant was calculated to be 0.0547g/g.min with correlation coefficient of 0.984. Based on Temkin isotherm model, heat of sorption was found to be -2 704.77J mol-1 and the equilibrium binding constant comparable to the ultimate binding energy was 13.255Lg-1. The mechanism showed that the process was a chemisorption type of adsorption. Activated carbon was established to be very efficient in adsorption of industrial effluents with percentage removal reaching up to 100%. |