Removal of Cadmium Using Chitosan

Cadmium removal efficiency of chitosan is studied using batch experiments. Studies indicate that sorption kinetics as well as capacity are highly favorable for using chitosan as an adsorbent. There is a significant increase in sorption capacity with a decrease in particle size of chitosan. Cadmium removal is pH dependent and increased up to pH 8.3. The presence of chloride ion and ionic strength has no significant effect. Heavy metal ions such as zinc and soluble complexing agents such as ethylenediamine tetracetate (EDTA) decrease the sorption of cadmium. Used chitosan can be regenerated with acid and reused. Column studies using cadmium spiked tap water show that the presence of calcium, magnesium, bicarbonate, and chloride ions in tap water do not affect the cadmium removal capacity of chitosan.