Illustration of linear forms of various isotherm models along with their application in water-soluble dye removal.
| Isotherm | Equation (linear) | Dye removed | Ref. |
|---|---|---|---|
| Henry | q e = KHECe | Acid yellow 194 | 186–188 |
| Acid red 357 | |||
| Acid black no. | |||
| Malachite green | |||
| Methylene blue | |||
| Langmuir isotherm |
|
Brilliant green | 114 and 189 |
| Freundlich isotherm |
|
Fluorescein | 114 and 189 |
| Eosin | |||
| Dubinin–Radushkevich | ln qe = qs − Kε2 | Methyl orange | 190 and 191 |
| Malachite green | |||
| Temkin |
|
Methyl orange | 188, 190 and 192 |
| Remazol brilliant blue R | |||
| Methylene blue | |||
| Flory–Huggins |
|
Remazol brilliant blue R | 188, 192 and 193 |
| Malachite green | |||
| Methylene blue | |||
| Hills |
|
Methylene blue | 188 and 194 |
| Crystal violet | |||
| Halsey | Log qe = (1/nH)ln KH − (1/nH)ln Ce | Methylene blue | 195 and 196 |
| Crystal violet | |||
| Malachite green | |||
| Jovanovich | ln qe = ln qmax − KJCe | Methylene blue | 188 and 197 |
| Erichromr black T | |||
| BET |
|
Basic blue 9 | 198 and 199 |
| Acid blue 29 | |||
| Acid red 91 | |||
| Disperse red 1 | |||
| Basic blue |