Cadmium and cobalt removal from heavy metal solution using oyster shells adsorbent

This paper investigated the adsorption capacities of crushed oyster shells adsorbent for cadmium and cobalt removal from heavy metal aqueous solution using batch experiments and column experiments. The results showed that: A 24 hour 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 cadmium ion removal 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 nickel and cadmium binary aqueous solution at a rate of 1.5 mL/min, the best cadmium treatment efficiency observed was 49.2%.