RECOVERY OF ZINC FROM ACIDIC WASTE-WATER USING CHARCOAL

Adsorption studies of Zn2+ form air acidic solution was carried out using charcoal. The effect of various parameters like contact time, pH of the solution, temperature, initial Zn2+ ion concentration, pulp density and particle size of charcoal were carried out. The adsorption of Zn2+ on charcoal showe two different kinetics with time, i.e., faster followed by a slower rate. The percentage of adsorption increased with pH upto 450 and thereafter the pH effect was marginal. With temperature also the adsorption rate is increased upto 52 degrees C and thereafter increase was marginal. The energy of activation was calculated to be 4.4 kcal.mol(-1) which suggested a diffusion controlled mechanism. The adsorption rate increased with decrease of particle size of charcoal and increase of S/L ratio. The Zn loaded charcoal was desorbed using an acid solution containing 5 kg.d(-3) of H2SO4.