Table 5.
Batch and column adsorption models and its parameters.
Adsorption model | Linear equation | Plot | Parameters of model | Heavy metals | |||||
---|---|---|---|---|---|---|---|---|---|
Pb | Cu | Cd | Zn | Ni | Cr | ||||
Batch isotherm | |||||||||
Langmuir | KL (L/mg) | 0.0678 | 0.0604 | 0.0554 | 0.0454 | 0.0401 | 0.0381 | ||
qm (mg/g) | 174.7 | 154.5 | 144.2 | 133.4 | 122.5 | 111.5 | |||
R2 | 0.9984 | 0.9985 | 0.9963 | 0.9987 | 0.9948 | 0.9981 | |||
Freundlich | KF (L/mg) | 19.2514 | 17.4514 | 15.1424 | 10.1578 | 7.1212 | 6.0287 | ||
n (-) | 0.2451 | 0.3125 | 0.3525 | 0.3747 | 0.4001 | 0.4212 | |||
R2 | 0.9875 | 0.9884 | 0.9825 | 0.9810 | 0.9840 | 0.9864 | |||
Temkin isotherm | b (kJ/mol) | 750.25 | 725.12 | 645.45 | 640.12 | 632.2 | 603.1 | ||
KT (L/gm) | 45.45 | 56.45 | 75.45 | 80.12 | 85.12 | 89.23 | |||
R2 | 0.9758 | 0.9721 | 0.9756 | 0.9752 | 0.9745 | 0.9762 | |||
Column isotherm | |||||||||
Thomas model | vs. time | kTH (mL/mg·min) | 0.6112 | 0.5124 | 0.5714 | 0.6555 | 0.5457 | 0.5252 | |
q0 (mg/g) | 205.6 | 185.8 | 154.5 | 133.3 | 120.6 | 110.9 | |||
R2 | 0.9858 | 0.9812 | 0.9898 | 0.9878 | 0.9852 | 0.9811 | |||
Bed depth service time model | Bed-height vs. time | kBDST (mL/mg·min) | 0.3787 | 0.3353 | 0.3232 | 0.3425 | 0.2785 | 0.3011 | |
No (mg/g) | 9784.5 | 9524.5 | 9455.5 | 9335.6 | 9248.0 | 9025.3 | |||
R2 | 0.9788 | 0.9699 | 0.9787 | 0.9785 | 0.9758 | 0.9785 | |||
Adam and Bohart model | vs. time | kAB × 10–5 (1/mg·min) | 8.7822 | 7.4521 | 8.0127 | 7.8784 | 6.4510 | 6.2122 | |
No (mg/L) | 9557.5 | 9218.2 | 9025.2 | 8956.1 | 8356.9 | 8124.5 | |||
R2 | 0.9757 | 0.9787 | 0.9752 | 0.9788 | 0.9745 | 0.9756 |