Research Article
Aminopropyl Functionalised MCM-41: Synthesis and Application for Adsorption of Pb(II) and Cd(II)
Table 3
Parameters of the isotherm equations determined by using the linear form of Pb(II) and Cd(II) adsorption on aminopropyl-MCM-41.
| Ion | Isotherm (linear form) | qm (mg·g−1) | KL, KF, KR, or KS2 | aR or aS | n, bR, or bS | R2 |
| Pb(II) | Langmuir 1 | 66.66 | 5.00 | — | — | 0.574 | Langmuir 2 | 66.66 | 7.50 | — | — | 0.999 | Langmuir 3 | 63.99 | 4.67 | — | — | 0.552 | Langmuir 4 | 64.64 | 2.57 | — | — | 0.552 | Langmuir 5 | 64.56 | 2.64 | — | — | 0.574 | Freundlich | — | 59.73 | — | 62.50 | 0.523 | Redlich–Peterson | — | 341.86 | 5.39 | 0.99 | 0.999 | Sips | — | 500.00 | 7.50 | 0.68 | 0.583 |
| Cd(II) | Langmuir 1 | 14.28 | 0.21 | — | — | 0.888 | Langmuir 2 | 14.28 | 0.22 | — | — | 0.991 | Langmuir 3 | 14.13 | 0.22 | — | — | 0.815 | Langmuir 4 | 14.54 | 0.18 | — | — | 0.815 | Langmuir 5 | 14.40 | 0.19 | — | — | 0.888 | Freundlich | — | 7.58 | — | 7.46 | 0.828 | Redlich–Peterson | — | 2.96 | 0.20 | 1.00 | 0.996 | Sips | — | 3.27 | 0.22 | 0.97 | 0.888 |
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