Surfactant-Modified Wheat Straw: Preparation, Characterization and its Application for Methylene Blue Adsorption from Aqueous Solution

Abstract

This work reports on the development of organo-modified wheat straw (WS) adsorbent prepared by using sodium dodecyl sulfate (SDS) for removing methylene blue (MB), a model cationic dye, from aqueous solution. The samples were characterized by scanning electron microscope (SEM), nitrogen physisorption and Fourier transforms infrared spectroscopy (FT-IR). Batch adsorption experiments were carried out to remove MB from its aqueous solutions using SDS modified WS (SMWS). Analysis of adsorption results showed that the adsorption pattern on the SMWS can be described perfectly with Langmuir isotherm model compared with Freundlich isotherm model, and the Langmuir adsorption capacity, Qmax was found to be 126.60 mg g-1 for SMWS and 55 mg g-1 for WS at 303K respectively. The adsorption kinetic followed the pseudo-second order kinetic model. Desorption studies suggest that MB adsorption onto the SMWS should be mainly controlled by the hydrophobic interaction mechanism, along with a considerable contribution of the cationic exchange mechanism.