Table 4 Isotherm parameters of UiO-66 prepared for the removal of rifampicin from wastewater.
Model | Equation | Parameter | Value | Q max | R2 |
|---|---|---|---|---|---|
Two parameters | |||||
Langmuir isotherm | \(\:{q}_{e}={q}_{{max}}\left(\frac{{k}_{L}{C}_{e}}{1+{k}_{L}{C}_{e}}\right)\) | KL | 44,932 | 110.88 | 0.97 |
Freundlich isotherm | \(\:{q}_{e}={k}_{F}\:({{C}_{e})}^{\raisebox{1ex}{$1$}\!\left/\:\!\raisebox{-1ex}{$n$}\right.}\) | 1/n | 0.217 | – | 0.995 |
KF | 46.38 | – | 0.997 | ||
Temkin isotherm | \(\:{q}_{e}=\frac{RT}{{A}_{T}}{ln}{A}_{T}+\frac{RT}{{A}_{T}}Ln\:{C}_{e}\) | RT | 8.31 | ||
AT | 1.64 | ||||
Dubinin‒Radushkevich isotherm | \(\:{q}_{e}=\left({q}_{max}\right){exp}\left(-{k}_{ad}{\epsilon\:}^{2}\right)\) | Kad | 0.0017 | 145.19 | 0.9997 |
Three parameters isotherm | |||||
Langmuir–Freundlich isotherm | \(\:{q}_{e}=\frac{{q}_{max}{\left({k}_{LF}\:{C}_{e}\right)}^{\text{M}\text{L}\text{F}}}{1+{\left({k}_{LF\:}{C}_{e}\right)}^{\text{M}\text{L}\text{F}}}\) | KLF | 0.086 | 139.188 | 0.999 |
MLF | 1.47 | ||||
Sips isotherm | \(\:{q}_{e}=\frac{{\left({q}_{max}{k}_{s}\:{C}_{e}\right)}^{1/n}}{{\left(1+{k}_{s}\:{C}_{e}\right)}^{1/n}}\) | KS | 0.027 | 139.189 | 0.999 |
1/n | 1.47 | ||||
Redlich–Peterson isotherm | \(\:{q}_{e}=\frac{{k}_{R\:\:}{C}_{e}}{1+{a}_{R\:\:}{{C}_{e}}^{\beta}}\) | KR | 8.5 | – | 1 |
aR | 0.026 | ||||
β | 1.149 | ||||
Toth isotherm | \(\:{q}_{e}=\frac{{k}_{e}\:{C}_{e}}{{\left(1+{\left({k}_{L}\:{C}_{e}\right)}^{n}\right)}^{1∕n}}\) | Ke | 9.76 | – | 1 |
KL | 0.026 | ||||
N | 1.15 | ||||
Kahn isotherm | \(\:{q}_{e}=\frac{{q}_{max}{\:b}_{k\:}{C}_{e}}{{\left(1+{b}_{k\:}{C}_{e}\right)}^{{a}_{k}}}\) | bk | 0.037 | 243.58 | 0.9999 |
ak | 1.218 | ||||
Higher parameter isotherm | |||||
Baudu isotherm | \(\:{q}_{e}=\frac{{q}_{max}{\:b}_{0}{\:{C}_{e}}^{1+X+Y}}{1+{b}_{0}{\:{C}_{e}}^{1+X}}\) | bo | 0.01 | 49.9 | 0.998 |
X | 0.012 | ||||
Y | 0.248 | ||||
Fritz–Schlunder isotherm | \(\:{q}_{e}=\frac{{q}_{{max}_{Fss}}{k}_{1}{{C}_{e}}^{{m}_{1}}}{1+{k}_{2}{{C}_{e}}^{{m}_{2}}}\) | K1 | 0.855 | 54.2 | 0.995 |
K2 | 0 | ||||
m1 | 0.217 | ||||
m2 | 0 | ||||