Adsorption Properties of Copper (II) Ion From Aqueous Solution by Starch-Grafted Polyacrylamide and Crosslinked Starch-Grafted Polyacrylamide

Relationship between Commonly Used Adsorption Isotherm Equations Impedes Isotherm Selection

“…These results mean, that the bi-Langmuir model can indeed quite closely approach the Freundlich isotherm. In the literature one can find many papers where isotherms have been measured with 5-10 % standard deviation [24,25]. With such precision it appears impossible to decide if isotherm data which can be fitted reasonably with the Freundlich equation are indeed Freundlich type or rather bi-Langmuir type.…”