Study of Adsorption Isotherm and Kinetics of Reactive Yellow Dye on Modified Wheat Straw

Abstract

In this study, the adsorption of reactive yellow dye which is one of the most commonly used soluble dyes in textile industries was studied using modified wheat straw, the surface of raw wheat straw was modified with a cationic surfactant CTAB. to understand the adsorption behavior of the reactive yellow, dye the adsorption kinetics and the adsorption isotherm studies have been investigated. Batch experiments was carried out with an initial concentration of 10 mg/L with 0.5 gm of adsorbent to study the contact time of equilibrium and then the adsorption mechanism process using three kinetic models; Pseudo-first, second order and intra-particle model. Isotherm studies was carried out at three different adsorbent amounts (0.1, 0.2, 0.4, 0.6, 0.8 and 1.0) gm to predict the type of adsorption process on the surface (chemical or physical) using three isotherm models; Langmuir, Freundlich and BET models. The results showed that the pseudo-second order is best fitted, intra-particle diffusion kinetic model fitted well to experimental data and is not the only controlling step of adsorption rate, and the adsorption isotherm follows both Langmuir and Freundlich models referring to the chemical adsorption.