**4. The potential of macro algae in absorbing heavy metals**

Macromolecular seaweeds are among the living and renewable resources of the seas and oceans, which are classified into three groups: brown, red, and green algae. Green and brown algae and their derivatives have a high absorption capacity for most metals. The adsorption capacity of brown algae is directly related to the algae content, its availability, and its specific macromolecular structure. It has been determined in the studies that the absorption power of *Sargassum* algae biomass for Cd+2, Pb2+, Zn2+, and Cu2+ ions is 79, 78, 227, and 51 mg/g, respectively. Two filamentous algae, Spirogyra and Cladophora, were also investigated for lead and copper absorption, and the results showed that Spirogyra's absorption power was higher. Also, the capacity of some species of macroalgae to absorb copper has been reported according to the following order [8, 16].

*Biological Treatment of Heavy Metals with Algae DOI: http://dx.doi.org/10.5772/intechopen.110301*

*Fucus spiralis* > *Ascophyllum nodosum* > *Chondrus crispus* > *Asparagopsis armata* > *Spirogyra insignis* > *Codium vermilara.*
