Keywords: 
• WAO /
• TNT redwater /
• BOD5 /
• COD /

Abstract: This paper compared the sorption performance of heavy metal by different sorbents. It also investigated the immobilization of Saccharomyces cerevisiae，effect of biomass on biosortion，and isotherm adsorption of Cd2+ and Cu2+ by free and immobilized Saccharomyces cerevisiae. The results indicated that the sorption capacity of free dead Saccharomyces cerevisiae for Cd2+ was three times of common activated carbon. The immobilization beads prepared by the ratio of 1∶3 (w/w) of alginate to dead yeast treated by 0.5M NaOH got best biosorption performance. The increase of biomass could reduce the unit biosorption capacity of Saccharomyces cerevisiae for heavy metals. The adsorption sites on surface of Saccharomyces cerevisiae for heavy metals were limited and the maximum biosorption capacities were 13.95 mg/g for Cd2+ and 7.67 mg/g for Cu2+ ，respectively. The isotherm adsorption process of Cd2+ and Cu2+ biosorption by free and immobilized Saccharomyces cerevisiae could be simulated by Linear equation，Langmuir equation and Freundlich equation. The Langmuir equation was best for the isotherm adsorption process of free Saccharomyces cerevisiae. Contrast to the maximum biosorption capacity of Cd2+ and Cu2+，the maximum biosorption capacity were respectively 13.96 mg/g and 8.01 mg/g for Cd2+ and Cu2+，according to Langmuir equation. The Freundlich equation simulating the isotherm adsorption process of immobilized Saccharomyces cerevisiae was better than other equations，and correspondingly the maximum biomass capacity was 75.41 mg/g and 66.58 mg/g for Cd2+ and Cu2+，respectively.