Abstract (EN):
Biosorption of Pb(II), Cd(II) and Zn(II) from binary metal solutions onto algalderived biomass, was investigated in a batch system at pH 5.3 and 20°C. Discrete andcontinuous equilibrium models were able to predict equilibrium results at differentequilibrium concentrations and pH values. The following sequence was obtained for themaximum uptake capacity and equilibrium affinity constants of metal ions to the activesites: Pb(II) > Cd(II) > Zn(II). The "iso-concentrations" cuts from the three dimensionalsorption isotherms, show that the uptake capacity of Cd(II) and Zn(II) decreaseddrastically in the presence of Pb(II). On the other hand, for the Cd(II)/Zn(II) system itwas concluded that Zn(II) uptake capacity is more sensitive to the presence of Cd(II) thanthe opposite. From discrete model the Langmuir affinity parameter, KL, can bedetermined as a function of pH and co-cation concentration. The KL values for Cd(II) andZn(II) decreased drastically in the presence of Pb(II), showing a higher affinity of thebinding sites to Pb(II).
Language:
English
Type (Professor's evaluation):
Scientific
No. of pages:
13