Adsorption behavior of victoria blue dye on halloysite nanotubes from aqueous solutions

Abstract

This study examines the adsorption and electrokinetic properties of victoria blue dye (VB) onto halloysite nanotubes from aqueous solutions. The adsorption of VB was studied with batch experiments. Equilibrium was rapidly attained after 60 min of contact time. The halloysite nanotubes used as adsorbent in this work were initially characterized by BET, XRD, FTIR-ATR, SEM/EDX and Zetasizer Nano ZS. The zeta potential of the halloysite was negative in the wide pH range (>2.2) and indicated that the material had a potential for binding of cationic dyes. The effects of pH, ionic strength and temperature on adsorption process were investigated. Adsorption increased with increasing initial pH, ionic strength and temperature. The Langmuir and Freundlich models were applied to describe the equilibrium isotherms and the Langmuir model agreed very well with experimental data. The isosteric heat of adsorption (Delta H degrees) indicated that the adsorption process was spontaneous and endothermic. The obtained results indicated that the halloysite nanotubes had the potential to be utilized as low-cost and effective alternative for dye removal in wastewater.