Table 2.
Fitting parameters of adsorption kinetic models for the adsorption of Pb2+ and Cd2+ onto BSL-BC.
| Kinetic model | Fitting parameter | Pb2+ | Cd2+ |
|---|---|---|---|
| Pseudo-first-order | Qe (mg g−1) | 239.8 | 45.01 |
| K1 | 0.034 | 0.219 | |
| R2 | 0.656 | 0.635 | |
| Pseudo-second-order | Qe (mg g−1) | 242.1 | 47.51 |
| K2 | 0 | 0.006 | |
| Intra-particle diffusion | R2 | 0.999 | 0.999 |
| Kd (mg g−1 h−1/2) | 2.192 | 0.064 | |
| I (mg g−1) | 164.3 | 45.28 | |
| R2 | 0.934 | 0.738 |
The values of Kd and I were obtained from the slope and intercept of the second linear regime of the intra-particle diffusion model, respectively. The solutions containing 0.8 g/L BSL-BC and initial concentrations of 200 mg/L Pb2+ (pH 5.0) or 50 mg/L Cd2+ (pH 5.5) were mixed at 180 rpm and 25 °C.