Fitting a little-known isotherm equation to S-shaped adsorption equilibrium data

A research topic of current interest concerns the measurement and modeling adsorption isotherms water contaminants. The bulk measured equilibrium exhibit convex-upward or favorable curve shape, which can be described by two-parameter Hill-Langmuir Freundlich isotherms. An increasing number recent studies have however reported S-shaped sigmoidal Modeling such data requires use isotherm equations with a highly flexible functional form. This work introduces little-known useful for tracking trajectory data. relatively simple three-parameter isotherm, first proposed Krishnamurti in 1951, has theoretical merit because it is based on co-operative mechanism. It shown that previously contaminants represented isotherm. Specific examples discussed are (1) ammonium ion clay mineral sepiolite, (2) uptake antibiotic ciprofloxacin magnetic nanosorbent, (3) fluoride removal layered double hydroxide adsorbent. Additionally, found modified form superior to its original counterpart. practically very describe adsorptive process modeling.