Application of Nano-Gamma Alumina Adsorbent for Nickel and Cobalt Removal from Mining Industry Wastewater

The development of urbanization and industries has led to an increase in sewage and wastewater production. The defective and non-standard disposal of these wastewaters has resulted in influx of large amounts of heavy metals into the environment which their removal, as bio-irresolvable contaminants, from water and wastewater are considerably important for protecting environment and public health.

In this study, gamma Nano-alumina was synthesized and its structural analysis was characterized, which was applied as a high performance adsorbent for heavy metals Nickel and Cobalt. Moreover, by using DX7 software for experiment design, the effects of different conditions such as heavy metals initial concentration, Nano-adsorbent amount and pH were modified. 

The results of XRD, FTIR, SEM and EDX analysis, confirmed the existence of gamma      Nano-alumina structure, and Nickel and Cobalt contents were determined by UV-Vis spectrophotometry method. Nano gamma alumina, as a powerful adsorbent, could be adsorbed the high levels of Nickel and Cobalt in alkaline pH-rich environments, then in experimental samples, 98.66% of Nickel and 95.1% of Cobalt and in real samples, 100% was eliminated. 

It was found that synthesized gamma Nano-alumina could be considered as a cost-effective and high-performance Nano-absorbent for heavy metals elimination. Consequently, it was verified by Freundlich and Langmuir adsorption isotherms, which the adsorption process of these elements with the Nano-alumina absorbent followed by Freundlich and Langmuir adsorption equation.