Removal of Methylene Blue by lava adsorption and catalysis oxidation

Abstract

Adsorption has been found to be effective for the removal of dyes from effluent; however, the contaminant will cause secondary pollution if it is not properly treated. In this paper, the ability of lava as a low‐cost adsorbent and catalyst for the removal of a commercial dye, Methylene Blue (MB), from aqueous solution has been investigated under various experimental conditions. It was found that lava had a high efficiency (more than 98%) for MB removal by adsorption. The adsorption equilibrium data can be fitted well by the Langmuir adsorption isotherm model. The adsorption kinetics was shown to be pseudo‐second‐order. After adsorption the contaminant could be catalysis oxidized by lava with the aids of H₂O₂ and ultrasound. The result showed that 95% of the MB could be decomposed in 100 min with the aid of ultrasound at 85 W/cm². Overall, this study demonstrates lava as a promising material for wastewater treatment to remove and decompose dyes in a single treatment step.