Efficient removal of brilliant blue by clinoptilolite tuff modified with Fe3+ and Fe-Cu nanoparticles

Abstract

Ferric-modified zeolitic tuff (Ze–Fe) and a composite of that modified zeolite bearing Fe–Cu nanoparticles (Ze–Fe(Fe–Cu)) were investigated for the removal of brilliant blue. The composite was synthesized by in-situ reduction of Fe and Cu salts using borohydride. Both materials were characterized by BET, X-ray diffraction, scanning electron microscopy, transmission electron microscopy (TEM), and infrared spectroscopy. TEM demonstrated that nanostructures of Fe–Cu (11.70–15.85 nm) were successfully dispersed on the zeolitic tuff. Batch experiments showed that the adsorption of dye is more favorable for Ze–Fe(Fe–Cu) than Ze–Fe; the kinetic adsorption data followed the second-order kinetic model. The results also showed that the removal of the dye was the highest between pH 3 and 5 for both materials. The removal of brilliant blue was 87.02% for Ze–Fe(Fe–Cu) and 75.29% for Ze–Fe. The ΔH° values of 52.60 kJ/mol for Ze–Fe and 126.29 kJ/mol for Ze–Fe(Fe–Cu) indicated that the adsorption processes are endothermic for both materials.