Removal of Cadmium and Cobalt from Heavy Metal Solution Using Oyster Shells Adsorbent

Abstract

This paper investigated the adsorption capacities of crushed oyster shells adsorbent for removal of cadmium and cobalt from aqueous solution of heavy metal using batch experiments and column experiments. The results showed that: A 24 h period was considered to provide an adequate contact time between the single-constituent metal ion solutions and the adsorbent to reach equilibrium. The equilibrium adsorption capacities of the adsorbent for single-constituent metal ion solutions was noted to be Cd > Co.Considering solution pH changes, crushed oyster shells could be a better natural adsorbent in full-scale applications where final solution pH considerations are required. Crushed oyster shells were found to be a better adsorbent for removal of cadmium ion in column testing. When a 10 cm diameter fixed-bed column packed with a 15 cm depth of crushed mollusk shells was hydraulically loaded with a cobalt and cadmium binary aqueous solution at a rate of 1.5 mL/min, the best cadmium treatment efficiency observed was 49.2 %.