Impact of different phase structure nano Al2O3 arc discharge prepared on MB dye removal

Abstract

Nanocrystalline ceramic materials have great importance in the field of nanotechnology. Nano-sized materials have properties superior to bulk materials, including improved surface area-to-volume ratio and high strength and toughness. Nano alumina products were prepared in two different phases with different sizes, and shapes via a solid–liquid plasma reactor. Both yields were prepared in identical circumstances, but with different conditions that lead to produce different shapes, and phase structures (γ-Al2O3-NPs with a spherical shape, and δ-Al2O3-Nano-structure rhomboid shape). In this regard, 1.6 million tons of dyes are consumed each year. Trace of dyes in water may cause diseases if it exceeds the WHO limits. This paper describes the adsorption of methylene blue (MB) from aqueous solutions by two different nano structure alumina nano-adsorbents. The optimum contact time, adsorbent mass, and pH were determined, and adsorption isotherms were obtained using concentrations of MB ions ranging from 5 to 50 mg/L. The adsorption process shows significant differences of the coefficient of determination factor R2 for both yields for pseudo-first-order reaction kinetics, as well as Freundlish and intraparticle, film diffusion adsorption isotherms. Our results demonstrate that the adsorption process was spontaneous and exothermic under natural conditions. The maximum capacity of adsorbent for γ-Al2O3-NPs and δ-Al2O3-Nano-structure were 31.56 and 29.49 mg/g, respectively. This study revealed that nano structure γ-alumina was an effective adsorbent for removal of these ions from aqueous solutions.