Biosorption kinetics of Baker's yeast in lead and copper waste water

The kinetics biosorption behavior of Baker's yeast in the simulation heavy metal waste water of Pb2+-Cu2+ was investigated.The autoclaved Baker's yeast was chosen as a biosorbent,and then the kinetics biosorption process and second-kinetics model were analyzed,respectively.The results show that there is very good biosorption effect at first 60 min.At the same initial concentration for heavy metal ions,there are the relations:qt(Pb2+)qt(Pb2 +-Cu2+) qt(Cu2+).The second-kinetics biosorption model's analysis shows that the biosorption speed to Pb2+ becomes rapid with the initial concentration of Cu2+ increasing,proving that there is obvious advantage to Pb2+ in the biosorption sites competition process.And the analysis results of EDS approve it also.The analysis of SEM shows that the Baker's yeast cells are broken after the biosorption of Pb2+ and Cu2+ ions.The toxicity of heavy ions to yeast cells makes the cells distort and break.The cytoplasm leaks out from the yeast cells.The biosorption of baker's yeast to Pb2+ and Cu2+ is a rapid and preferable process,and there is a more obvious advantage for Baker's yeast to Pb2+ than Cu2+.