Biosorption Behavior of Strontium Ions and Mechanism Analysis on Baker's Yeast

The baker's yeast was utilized as biosorption material to remove Sr2+ from simulant aquous solution.The effect factors on biosorption were analyzed,which included pH values,initial concentration(c0),adsorbent concentration(ρm),and temperature(t).Meanwhile,the correlation biosorption thermodynamics was analyzed and the mechanism of biosorption was researched.The results show that the optimum condition for biosorption is as follows: pH=4.5,t=30 ℃,c0=1.0 mmol/L,ρm=4.0 g/L.The isotherm adsorption curve of Sr2+ under different temperatures accords well with the Langmuir and Freunlich absorption models,and both R2 are above 0.988.The biosorption of Sr2+ by yeast can proceed spontaneously under different temperatures.And the higher temperature is in favour of the spontaneous process of Sr2+ biosorption at the range of 10-30 ℃.The analysis indicates that there is chemisorption in the course of Sr2+ biosorption by yeast.The components of yeast cell,including polysaccharide and amide protein,are involved in the Sr2+ biosorption.And the principal absorption sites are the active sites on the cell wall surface.