Study of Isotherm and Kinetics Parameters for Methylene Blue Adsorption onto Wheat Straw

Abstract

In this work, the wheat straw (WS) was used as an adsorbent. The adsorption of methylene blue (MB) from aqueous solutions onto WS has been studied. Four widely isotherms, Langmuir, Freundlich, Temkin and Sips were examined for MB sorption at different temperatures. The Langmuir isotherm found to be the best to describe sorption of MB on WS. The Langmuir adsorption capacity (Qmax) was found to be 172.41 mg g−1. The Sips and Temkin isotherms were also satisfactory but the Freundlich isotherm couldn’t describe sorption appropriately in this case. The removal of MB by WS followed pseudo-second order reaction kinetics