EVALUATION OF PACKED ADSORPTION COLUMN FOR LEAD, CADMIUM AND ZINC REMOVAL USING DIFFERENT BIOSORBENTS

摘要

The present article describes the adsorption of cadmium, lead and zinc ions using waste products and natural low-cost products (olive waste, maize cobs, bentonitic clay, wheat bran, coal ash and coffee waste) in a packed adsorption column. A solution of known concentration of cadmium, lead and zinc were allowed to pass through an adsorption column that contained different biosorbents. The amounts of cadmium, lead and zinc ions were measured using Flame Atomic Absorption Spectroscopy in terms of their residual concentration in three fractions (FI, FII, FIII), at the outlet stream. The result showed that the increase of the adsorbents amount increases the percentage of metal ions removal; also increasing of contact time (third fraction FIII, which is longer in column) increases the percentage of metal ions removal. Also analysis of the mixture of all three metal solutions passing through column was carried out. Gained results showed that percentage of removal of cadmium, lead and zinc ions in mixture was almost the same as it was when each metal alone was allowed to pass through column.