Phycoremediation of heavy metals by the three-color forms of Kappaphycus alvarezii

In the present investigation, three living color forms (brown, green and pale yellow) of Kappaphycus alvarezii were examined for their biosorption ability in the laboratory. The brown color form proved to be an excellent metal biosorbent, i.e. it could adsorb good amount of cadmium 3.064 mg/100 gf.wt. and cobalt 3.365 mg/100 gf.wt. It also removed 2.799 mg/100 gf.wt. of chromium. The green color form absorbed 2.684, 3.43 and 2.692 mg/100 gf.wt. of cadmium, cobalt and chromium, respectively. In contrast, the pale yellow form removed almost equal proportion of cadmium 0.961 mg/100 gf.wt. and chromium 0.942 mg/100 gf.wt. It also removed 1.403 mg/100 gf.wt. cobalt. Thus, the living color forms of this seaweed could form an effective biosorbent material for removal of heavy metals.