Biosorption of Cadmium by Fungal Strains Isolated from Wastewater of Zanjan Leads and Zinc Plants

In this study the biosorption of cadmium from industrial wastewater was studied by isolated fungal strains. For this purpose, the effluent samples were collected from leads and zinc plant of Zanjan. Then, cadmium resistant strains (yeast and a mold) were isolated by cultivation on BHI agar containing cadmium sulfate. After preparing the living and dead biomass, the effect of pH, initial metal concentration and contact time in removal of cadmium was investigated. In this study it was found that the dead biomass of yeast and mold were able to remove86.95% and 58.65% of cadmium from the samples respectively. The results also showed that the living biomass of yeast and mold removed cadmium 29.84% and 31.94% reapectively. Most removal occurred after 60 minutes of contact time.. These strains were identified by 18SrRNA PCR sequencing method. Yeast strain had 99% homology with Rhodosporidium toruloides SM30and mold strain had 100% homology with Aspergillus melleus. Thus, these strains could be used for bioremediation studies in semi-industrial scale.