John Isotherm for Liquid Phase Adsorption: Comparisonwith Langmuir and Freundlich models

摘要

John (J) isotherm log log P = C + n log V [J. Mate. Sc. 37 (2002) 885-893] has many advantages compared toother working isotherms. The equation conforms to a single line for micropore adsorption representing onephase of adsorption with slope n giving the limiting micropore volume (LMV) as log Vm. Modified form, log logCe = C + n log q can be successfully used to plot any isotherm data that belong to type I. The extrapolation tosaturation Cs and the corresponding surface loading (qs) can be taken as the monolayer capacity (qm). It isobserved that, adsorbability constant n of John is a function of energy of adsorption kL of Langmuir andadsorption intensity constant m of Freundlich isotherm.