Table 1 (a) Parameters of the linear and nonlinear pseudo-first model for Cr(VI) adsorption on PSD at different initial concentrations; (b) Parameters of the linear and nonlinear pseudo-second order model for Cr(VI) adsorption at different initial concentrations
(a) | |||||||
|---|---|---|---|---|---|---|---|
C0/mg L−1 | qe,exp/mg g−1 | Pseudo first order | |||||
Linear form | Nonlinear form | ||||||
qe,cal/mg g−1 | k1/min−1 | R2 | qe,cal/mg g−1 | k1/min−1 | R2 | ||
5 | 1.06 | 0.56 | 1.68 × 10–2 | 0.9686 | 0.99 | 4.95 × 10–2 | 0.8232 |
7.5 | 1.54 | 0.95 | 1.68 × 10–2 | 0.9977 | 1.41 | 4.47 × 10–2 | 0.7521 |
10 | 2.1 | 1.37 | 1.11 × 10–2 | 0.9842 | 1.91 | 2.92 × 10–2 | 0.853 |
25 | 4.1 | 2.99 | 7.08 × 10–3 | 0.9917 | 3.43 | 2.08 × 10–2 | 0.8879 |
50 | 5.2 | 4.03 | 1.01 × 10–2 | 0.9948 | 4.69 | 1.96 × 10–2 | 0.8996 |
(b) | |||||||
|---|---|---|---|---|---|---|---|
C0/mg L−1 | qe,exp/mg g−1 | Pseudo second order | |||||
Linear form | Nonlinear form | ||||||
qe,cal/mg g−1 | k2/g−1 mg−1 min−1 | R2 | qe,cal/mg g−1 | k2/g−1 mg−1 min−1 | R2 | ||
5 | 1.06 | 1.1 | 6.38 × 10–2 | 0.9995 | 1.09 | 6.92 × 10–2 | 0.9336 |
7.5 | 1.54 | 1.62 | 3.40 × 10–2 | 0.9992 | 1.56 | 4.26 × 10–2 | 0.8979 |
10 | 2.1 | 2.22 | 1.39 × 10–2 | 0.9951 | 2.16 | 1.81 × 10–2 | 0.9362 |
25 | 4.1 | 4.16 | 5.66 × 10–3 | 0.9941 | 3.98 | 6.39 × 10–3 | 0.9525 |
50 | 5.2 | 5.58 | 4.24 × 10–3 | 0.9954 | 5.45 | 4.39 × 10–3 | 0.9541 |