Table 1 Langmuir and Freundlich adsorption isotherm constants for the adsorption of Pb2+ ions on to GAC, HAP/GAC and HAP/TE/GAC
Material | Langmuir adsorption isotherm constants | Freundlich adsorption isotherm constants | ||||
|---|---|---|---|---|---|---|
qm (mg/g) | K (L/mg) | R2 | Kf | n | R2 | |
HAP/GAC | 36.9 (± 0.8) | 3.1 × 10−3 (± 1.1 × 10−4) | 0.9989 | 1.1 (± 0.2) | 2.0 (± 0.1) | 0.9939 |
GAC | 31.1 (± 2.3) | 3.6 × 10−3 (± 4.6 × 10−4) | 0.9891 | 1.4 (± 0.2) | 2.3 (± 0.2) | 0.9905 |
HAP/TE/GAC | 29.4 (± 7.2) | 3.1 × 10−3 (± 1.2 × 10−3) | 0.8931 | 1.1 (± 0.7) | 2.2 (± 0.6) | 0.8818 |