Chitosan is a versatile polymer with a cationic charge, which is used as a sorbent in wastewater treatment. It has a high reactivity and is able to adsorb pollutants from aqueous solutions. It is an effective sorbent and coagulant for a variety of industrial wastewaters and can be chemically modified to increase its adsorption capacity. Chitosan is a unique alternative adsorbent for toxic metals. It can be used to remove a wide range of heavy metals from aqueous solutions.