Table 2 Adsorption kinetic and diffusion model constants for MB removal using pure diatomaceous mesoporous biosilica.
Kinetic model | Pseudo-first order | Pseudo-second order | Elovich | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
q1, mg g−1 | k1, min−1 | R2 | Δq, % | q2, mg g−1 | k2, g (mg min)−1 | R2 | Δq, % | α, g (mg min)−1 | β, mg g−1 | R2 | Δq, % | ||
SZCZCH193 | 19.902 | 0.002 | 0.887 | 52.2 | 39.671 | 2.71e−5 | 0.894 | 65.4 | 0.042 | 0.051 | 0.893 | 64.7 | |
SZCZM1342 | 9.445 | 0.991 | 0.979 | 26.9 | 14.787 | 4.09e−4 | 0.964 | 28.2 | 0.094 | 0.178 | 0.969 | 29.6 | |
SZCZP1809 | 8.458 | 0.987 | 0.989 | 24.1 | 12.283 | 7.74e−4 | 0.973 | 28.9 | 0.130 | 0.237 | 0.976 | 32.3 | |
Diffusion model | Intra-particle (Weber-Morris) | Bangham’s pore diffusion | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Kwm, mg (g min 0.5)−1 | B, mg g−1 | R2 | Δq, % | Δβ | Kβ | R2 | Δq, % | ||||||
SZCZCH193 | 0.377 | 1e−16 | 0.730 | 52.2 | 1.374 | 0.004 | 0.972 | 18.2 | |||||
SZCZM1342 | 0.535 | 1e−14 | 0.901 | 26.9 | 1.025 | 0.037 | 0.964 | 13.9 | |||||
SZCZP1809 | 0.575 | 1e−14 | 0.930 | 24.1 | 1.073 | 0.035 | 0.985 | 19.2 | |||||
Isotherm | Langmuir | Freundlich | Sips | ||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
Q0max, mg g−1 | KL, L mg−1 | R2 | Δq, % | KF, (mg g−1) (mg L−1)−n | n | R2 | Δq, % | qm, mg g−1 | KS, [(mg L−1)−1/n] | n | R2 | Δq, % | |
SZCZCH193 | 6.85 | 0.31 | 0.965 | 11.9 | 2.37 | 0.27 | 0.953 | 19.6 | 8.39 | 0.16 | 0.65 | 0.992 | 7.2 |
SZCZM1342 | 16.18 | 1.35 | 0.959 | 48.9 | 1.88 | 1.10 | 0.965 | 36.3 | 19.02 | 0.26 | 2.26 | 0.998 | 6.5 |
SZCZP1809 | 27.09 | 0.24 | 0.879 | > 100 | 4.94 | 0.67 | 0.820 | > 100 | 15.17 | 0.75 | 2.87 | 0.999 | 20.9 |