Effects of coexisting ions on biosorption kinetics and equilibrium of Pb2+ by discarded brewers yeast in waste water

Effects of Cu2 +and Ni2 +on biosorption kinetics and equilibrium of Pb2 +by discarded brewers yeast were studied using static adsorption experiment.The experimental results indicated that the existence of Ni2 +extended the Pb2 +adsorption equilibrium time from 5min to 10 min, slowed the rate of Pb2 +adsorption, but it had almost no effect on Pb2 +adsorption capacity.The existence of Cu2 +reduced Pb2 +adsorption capacity markedly by 35.45%as the existence of Cu2 +and Ni2 +did ( 32.51%) .Competitive adsorption processes were fitted with pseudo-second order kinetics and Langmuir adsorption equation. Pseudo- second order kinetics ( R2 was 0.9953 ~ 0.9999) and Langmuir adsorption equation ( R2 was 0.9687~0.9824) can be used to describe competitive adsorption processes of Pb2 +by discarded brewers yeast under the experimental conditions.