Removal of Methylene Blue from Aqueous Solutions Using Luffa Adsorbent Modified with Sodium Dodecyl Sulfate Anionic Surfactant

Abstract

<p>Methylene blue is one of the most widely used dyes in various industries such as textiles and dyeing which, due to toxicity, causes several environmental problems as well as difficulties in wastewater treatment process. Therefore, many studies have been carried out on the removal of the dye from industrial wastewater and aqueous solutions using various adsorbents. In the present study, a Luffa adsorbent surface was first modified by sodium dodecyl sulfate anionic surfactant and then methylene blue dye removal from aqueous solution was studied under various operating conditions in batch experiments. The parameters addressed included of the dye solution pH, adsorbent amount, initial methylene blue concentration in the dye medium, and the duration of adsorption. The use of anionic surfactant changed the adsorbent surface charge and thus increasing absorbent ion exchange capacity. The results showed that the highest removal efficiency occurs in mediums with an initial concentration of 50 mg L-1 and pH 6-9, where 99% of the dye was removed from the medium using 1 gr modified adsorbent in 60 minutes. Since the obtained pH range covered the neutral and near neutral media, the adsorbent can be used in a variety of industries. Finally, the dye adsorption process was modeled and examining the adsorption isotherms, it was observed that the empirical data appropriately followed the Freundlich model.</p>