Table 1 Kinetics variables for the adsorption of lead ions by WBWA and VWBWA.
From: Utilization of valorised wood bark waste as an adsorbent for the uptake of Pb(II) ions
Co(mg/L) | WBWA | VWBWA | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
50.00 | 100.00 | 150.00 | 200.00 | 250.00 | 300.00 | 50.00 | 100.0 | 150.0 | 200.0 | 250.0 | 300.00 | ||
First order | Qe(exp) (mg/g) | 16.1 | 20.3 | 23.5 | 27.8 | 36.2 | 50.5 | 21.8 | 38.1 | 59.2 | 71.8 | 93.6 | 109.3 |
Qe(cal) (mg/g) | 17.408 | 19.703 | 24.792 | 28.24 | 35.132 | 51.183 | 22.44 | 36.27 | 60.57 | 72.03 | 90.04 | 107.03 | |
k1(mins− 1) | 0.013 | 0.038 | 0.015 | 0.017 | 0.021 | 0.031 | 0.153 | 0.178 | 0.208 | 0.235 | 0.482 | 0.853 | |
R2 | 0.997 | 0.996 | 0.993 | 0.997 | 0.970 | 0.991 | 0.988 | 0.993 | 0.979 | 0.968 | 0.996 | 0.998 | |
% SSE | 0.036 | 0.013 | 0.025 | 0.007 | 0.013 | 0.006 | 0.013 | 0.021 | 0.010 | 0.001 | 0.017 | 0.009 | |
Second order | Qe(cal) (mg/g) | 24.408 | 29.703 | 34.792 | 38.24 | 43.132 | 67.183 | 23.07 | 38.81 | 61.23 | 71.14 | 92.58 | 111.05 |
k2 (g/mg/min) | 0.018 | 0.024 | 0.055 | 0.078 | 0.142 | 0.676 | 0.173 | 0.261 | 0.352 | 0.393 | 0.619 | 0.344 | |
R2 | 0.798 | 0.896 | 0.684 | 0.798 | 0.896 | 0.786 | 0.996 | 0.998 | 0.988 | 0.997 | 0.994 | 0.996 | |
% SSE | 0.231 | 0.207 | 0.215 | 0.168 | 0.086 | 0.148 | 0.026 | 0.008 | 0.015 | 0.004 | 0.005 | 0.007 | |
Intra particle diffusion | Kp(mg/g/mins1/2) | 0.844 | 1.286 | 2.446 | 3.404 | 6.023 | 6.922 | 1.302 | 1.619 | 3.311 | 5.424 | 9.509 | 10.145 |
C (mg/g) | 0.172 | 0.227 | 0.671 | 1.059 | 1.122 | 1.341 | 0.658 | 0.955 | 1.156 | 1.569 | 2.439 | 2.726 | |
R2 | 0.987 | 0.996 | 0.979 | 0.992 | 0.988 | 0.992 | 0.992 | 0.986 | 0.988 | 0.993 | 0.997 | 0.989 | |
