Table 2 Adsorption isotherm parameters for removal of MG, MV, and MB
Model | Equation | Eq. | Ads. | Dye | Parameters for dye | Reference | |||
|---|---|---|---|---|---|---|---|---|---|
Modified Langmuir | \( \frac{C_{\mathrm{e}}}{q_{\mathrm{e}}}=\frac{C_{\mathrm{s}}}{K_{\mathrm{ML}}{q}_{\mathrm{m}}}+\frac{\left({K}_{\mathrm{ML}}-1\right){C}_{\mathrm{e}}}{K_{\mathrm{ML}}{q}_{\mathrm{m}}} \) | (3) | AP AP AP P P P | MB MG MV MB MG MV | qm 104.1 74.6 149.2 6.64 3.86 4.97 | KML 1100 1292 2381 3003 6089 4417 | R 2 0.996 0.966 0.996 0.986 0.994 0.994 | Azizian et al. 2018 | |
Freundlich | \( 1{nq}_{\mathrm{e}}=1{nK}_{\mathrm{f}}+\frac{1}{n}\;1{nC}_{\mathrm{e}} \) | (4) | AP AP AP P P P | MB MG MV MB MG MV | K f 4.87 2.64 12.22 1.07 0.70 1.10 | n 1.60 1.50 1.61 2.57 2.63 2.93 | R 2 0.981 0.931 0.949 0.997 0.950 0.966 | Freundlich 1906 | |
D-R | Inqe = lnqm − βε2 | (5) | AP AP AP P P P | MB MG MV MB MG MV | X m *10−3 7.25 6.04 14.33 0.29 0.19 0.22 | K 0.0073 0.0072 0.0058 0.0038 0.0039 0.0034 | E 8.84 8.33 9.29 11.47 11.32 12.13 | R 2 0.994 0.960 0.976 0.993 0.964 0.976 | Dubinin and Radushkevich 1947 |
Temkin | qe = BlnKT + BlnCe | (6) | AP AP AP P P P | MB MG MV MB MG MV | B 19.49 15.04 28.58 1.24 0.79 0.95 | K t 0.41 0.28 1.05 1.14 1.13 1.72 | R 2 0.959 0.971 0.966 0.969 0.953 0.961 | Temkin and Pyzhev 1940 | |
Scathard | qe/Ce = QsKs − qeKs | (7) | AP AP AP P P P | MB MG MV MB MG MV | Q s 108.0 96.71 188.5 5.95 3.89 4.90 | K s 0.03 0.017 0.059 0.118 0.101 0.150 | R 2 0.936 0.744 0.956 0.783 0.872 0.843 | Scatchard, 1949 | |