Original paper

Bioremoval of cadmium, cobalt and copper from laboratory cultures by cyanobacteria and green microalgae

Azab, Yehia; Kenawy, Ibraham; Mohamedin, Ateila; Ibrahim, Wael

Abstract

Survival of six algal strains, two blue greens (Anabaena oryzae and Nostoc ellipsosporum) and four greens (Chlamydomonas globasa, Chlorella ellipsoidea, Scenedesmus quadricauda var. longispina and Zygnema sp.) with different concentrations of Cd, Co and Cu has been examined together with the efficiency of each strain in bioremoval of each heavy metal from laboratory cultures. The toxicity of each heavy metal to every algal strain was compared with that of the standard test alga Selenastrum capricornutum* (=Raphidocelis subcapitata). The most tolerant and the best in bioremoval, in general, were found to be Chlorella ellipsoidea and Chlamydomonas globosa. The least strain in bioremoval was Zygnema sp. Moreover, all the strains used in this study had much higher tolerance to different concentrations of the above mentioned heavy metals compared with that of Selenastrum capricornutum. This work shows that the studied algal strains can be used for the bioremoval of Cd, Co and Cu from industrial effluents and other wastewaters.

Keywords

freshwater algaeheavy metalsbioremovaltoxicity assessment