Adsorption of ternary toxic crystal violet, malachite green and methylene blue onto synthesised SBA-15 mesoporous nanoparticles

Abstract

ABSTRACT In this research, SBA-15 mesoporous silica nanoparticles were synthesised and characterised using different techniques. Average particle size of synthesised SBA-15 was obtained to be 16 and 33.6 nm from field emission scanning electron microscopy image and X-ray diffraction analysis, respectively. Response surface methodology indicated that 70 mg L−1 initial dye concentrations, 0.1 g L−1 adsorbent dosage, 14 min contact time and pH 9, result in the best adsorption capacity of SBA-15 nanoparticles. According to analysis of variance, the most important factor on the adsorption of all dyes onto SBA-15 nanoparticles was adsorbent dosage. The equilibrium data were fitted by Langmuir isothermal model and adsorption kinetic data are more similar to the pseudo-first-order model. The thermodynamic analysis suggested that the adsorption of crystal violet (CV) and malachite green (MG) dyes on the SBA-15 nanoparticle is a spontaneous and endothermic process, meanwhile sorption of methylene blue (MB) dye was found exothermic. Also, the ΔG 0 value in the range of −0.27 to −7.1 kJ mol−1 revealed that adsorption of three dyes on SBA-15 nanoparticles was physisorption. Finally, performance of the developed model was applied for the removal of these dyes in river water and simulated industrial wastewater.