Removal of methylene blue by sawdust coated with magnesium oxide nanoparticles

Abstract

In this article, magnesium oxide (MgO) nanoparticles coated onto sawdust (SD) and its application as an efficient sorbent for removal of methylene blue dye has been reported. The introduced Nanocomposite was prepared through co-precipitation by addition of sawdust which has been previously soaked in magnesium sulfate solution into a NaOH solution. Adsorption studies was carried out in both batch and column systems. For determination of optimum dye removal conditions, the effect of parameters such as pH, initial dye concentration, sorbent dosage, contact time, and temperature were investigated in a batch adsorption system. The results indicated that SD/MgO nanocomposite is able for uptaking of methylene blue dye from aqueous solutions successfully. It was found that more than 95% dye removal is happened when 0.20 g adsorbent was treated with 100 mL of dye solution with initial concentration of 100 mg/L. The treatment of the data was also carried out using both Freundlich and Langmuir adsorption isotherms. Based on regression analysis, it was found that the sorption of methylene blue using nanocomposite of SD/MgO adopt Freundlich isotherm partially better than Langmuir isotherm. Maximum monolayer adsorption capacity has been obtained 59.17 mg/g. Kinetic studies have also been conducted and it was found that adsorption of methylene blue by SD/MgO follows with the pseudo-second-order kinetic model.

Keywords

• sawdust
• magnesium oxide nanoparticles
• nanocomposite
• adsorption
• methylene blue