Research Article
Evaluation of Activated Carbons Prepared from Bioprecursors for the Removal of Cadmium and Chromium (VI)
Table 2
Adsorption kinetics parameters of Cd and Cr(VI) on CA1 and CA2.
| Adsorbent | Element | CC (mg/l) | qe, exp(mg/g) | Pseudofirst order | Pseudosecond order | qe, cal(mg/g) | k1 (min−1) | | qe, cal(mg/g) | K2 (g·mg−1·min−1) | |
| CA1 | Cd | 25 | 4.178 | 4.550 | 0.041 | 0.949 | 4.244 | 2.945 | 0.995 | 40 | 6.597 | 5.781 | 0.023 | 0.912 | 7.043 | 2.353 | 0.994 | 50 | 7.966 | 7.430 | 0.032 | 0.902 | 8.072 | 2.392 | 0.991 | 70 | 11.070 | 11.041 | 0.030 | 0.922 | 11.448 | 1.489 | 0.994 | Cr(VI) | 25 | 3.687 | 2.438 | 0.039 | 0.921 | 3.817 | 1.799 | 0.999 | 40 | 5.644 | 2.710 | 0.041 | 0.828 | 5.780 | 0.669 | 0.999 | 50 | 6.750 | 2.523 | 0.032 | 0.634 | 6.897 | 0.591 | 0.999 | 70 | 8.938 | 6.607 | 0.046 | 0.968 | 9.259 | 0.716 | 0.999 |
| CA2 | Cd | 25 | 2.971 | 2.661 | 0.023 | 0.913 | 3.165 | 0.014 | 0.993 | 40 | 4.214 | 4.130 | 0.044 | 0.983 | 4.464 | 0.012 | 0.997 | 50 | 4.695 | 4.864 | 0.058 | 0.961 | 4.778 | 0.009 | 0.997 | 70 | 5.920 | 6.580 | 0.035 | 0.946 | 6.179 | 0.007 | 0.999 | Cr(VI) | 25 | 2.618 | 3.819 | 0.060 | 0.954 | 2.959 | 0.015 | 0.975 | 40 | 4.144 | 5.188 | 0.044 | 0.959 | 4.464 | 0.014 | 0.997 | 50 | 4.529 | 11.858 | 0.145 | 0.623 | 4.950 | 0.013 | 0.996 | 70 | 5.767 | 5.188 | 0.044 | 0.959 | 6.098 | 0.010 | 0.997 |
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CC: concentration of element; qe, exp: equilibrium adsorbed capacity; k1: pseudo-first-order constant; K2: pseudo-second-order constant; : correlation coefficient. |