Effect of Initial Metal Concentration on Biosorption Kinetics

The kinetic parameters involved in equation (11.9) were determined for the biosorption of cadmium, copper, and zinc by aerobic granules (Xu, 2006). This section discussed the effect of initial metal concentration on the biosorption kinetics of metal ions by aerobic granules.

Effect of Initial Metal Concentration on Specific Biosorption Capacity

The relationship between the metal ions uptake capacity and the initial concentration of Cd2+, Cu2+, and Zn2+ at the fixed initial granules concentration are illustrated in Figs 11.7-11.9, respectively. It can be seen that the metal biosorption capacity was positively related to the initial metal concentration. These results provide the evidence that the biosorption capacity at equilibrium is highly dependent upon the available

Initial Cd2+ concentration (mg/l)

Fig. 11.7. Effect of initial Cd2+ concentration on Qe (Liu et al., 2003a).

Fig. 11.7. Effect of initial Cd2+ concentration on Qe (Liu et al., 2003a).

Initial Cu2+ concentration (mg/l)

Fig. 11.8. Effect of initial Cu2+ concentration on Qe (Xu, 2006).

Initial Cu2+ concentration (mg/l)

Fig. 11.8. Effect of initial Cu2+ concentration on Qe (Xu, 2006).

binding sites on the aerobic granules surface, which are proportional to the quantity of aerobic granules. Puranik et al. (1999) also reported that the amounts of zinc and lead adsorbed onto S. cinnamoneum, P. chrysogeum, and Citrobacter sp. were increased with the increase of the initial metal concentration.

Fig. 11.9. Effect of initial Zn2+ concentration on Qe (Liu et al., 2002).

Initial Zn2+ concentration (mg/l)

Fig. 11.9. Effect of initial Zn2+ concentration on Qe (Liu et al., 2002).

Effect of Initial Metal Concentration on Overall Biosorption Rate Constant

The relationships between the overall biosorption rate constant (k) and initial metal concentration were shown in Figs 11.10-11.12 for various metal ions (Liu et al., 2003a; Xu, 2006). These results suggest that the increased initial metal concentration favors the biosorption of metal ions, i.e. a faster metal biosorption would occur at higher initial metal concentration.

Was this article helpful?

0 0

Post a comment