Study the adsorption of eosin dye by modified clay With urea-formaldehyde polymer

Abstract

Adsorption of eosin dye on attapulgite and AUFP composite was investigated by uvvisible
technique. While the adsorption of eosin dye had no affinity for the attapulgite, but
the AUFP showed significant adsorption from aqueous solution.
The Freundlich and Langmuir isotherm equations were applied to the data and values of
parameter of these isotherm equations were evaluated the adsorption.
The extent of the adsorption found to decrease as the temperature increased, i.e,
exothermic adsorption. The thermodynamic functions ΔHo, ΔGo and ΔSo were calculated and
explained in the mean of the chemical structure of the adsorbate.
Kinetic of adsorption was studied using Lagergren's equation and the adsorption rate
constant Kad was calculated, the kinetic results indicated that the adsorption was pseudo first
order and the rate determining step was demonstrated.
Activation energy was calculated using Arrehenius equation and it was found to be
dependent on the nature of the adsorbents surfaces.