Adsorption of copper and zinc by oil shale

Oil shale is able to remove appreciable amounts of copper and zinc ions fro m aqueous solutions. It was noted that an increase in the adsorbent concent ration with constant copper or zinc concentration resulted in greater metal removal from solution. An increase in the copper or zinc concentration wit h a constant sorbent concentration resulted in higher metal loading per uni t weight of sorbent. For both metals, copper and zinc, equilibrium was atta ined after 24-h contact time. Increase in the initial pH or temperature of the metal solution resulted in an increase in the metal uptake per unit wei ght of the sorbent. Freundlich isotherm model was found to be applicable fo r the experimental data of Cu2+ and Zn2+ The results showed that oil shale could be used for the adsorption of the Cu2+ and Zn2+ with higher affinity toward Zn2+ ions. Addition of sodium salt to the metal solution influenced copper removal positively, but inhibited zinc removal.