Fe3O4-CuO-activated carbon composite as an efficient adsorbent for bromophenol blue dye removal from aqueous solutions

Abstract

Dye wastewater from industries is posing tremendous health hazards. The lethal dyes can be eliminated using nanomaterials and scientific approach like adsorption which is facile, cheap, safe as well as ecofriendly. Fe3O4-CuO-AC composite was prepared by a hydrothermal method and used for the removal of dyes in wastewater. The composite material was characterized by various techniques such as XRD, SEM, EDS, TEM and FT-IR. The Fe3O4-CuO-AC composite was used to treat five types of dyes in water. Fe3O4-CuO-AC composite showed the highest adsorption capability for bromophenol blue (BPB) dye. The effects of initial concentration, pH, the amount of adsorbent and temperature were also studied. The optimum conditions were found to be 20 ppm dye concentration, pH 9, an adsorbent dose of 0.06 gL─1 at 65 °C. A removal efficiency of 97% was obtained for BPB dye during 120 min of adsorption. Kinetic studies indicated that a pseudo-second order is the most suitable model for the adsorption process. The Fe3O4-CuO-AC composite showed better adsorption capacity as compare to Fe3O4-AC except for the Methyl green dye. The maximum adsorption capacity was found to be 88.60 mg/g for BPB. Additionally, the thermodynamic parameters (ΔS°, ΔH° and ΔG°) showed that the process was spontaneous and exothermic. All the above results revealed that the Fe3O4-CuO-AC compositecan be an effective adsorbent for removing dyes from wastewater.

Keywords

• Fe3O4-CuO activated carbon composite
• Bromophenol blue
• Adsorption
• Thermodynamics
• Kinetics