Aluminum substituted nickel ferrite (Ni-Al-Fe): A ternary metal oxide adsorbent for arsenic adsorption in aqueous medium

Abstract

The adsorption of arsenic [arsenite (As(iii)) and arsenate (As(v))] onto aluminum substituted nickel ferrite (Ni-Al-Fe) which is a ternary metal oxide nano adsorbent is evaluated. Qualitative and quantitative studies were performed to understand the adsorption phenomenon. The qualitative studies for both adsorbent and arsenic adsorbed samples were evaluated using FT-IR, Raman and XPS techniques and the quantitative studies were carried out using ICP-OES technique. The results reveal that the maximum adsorption capacities of Ni-Al-Fe adsorbent are around 114 and 103 mg g-1 for As(iii) and As(v) species in 100 ppm arsenic equilibrium concentration (Ce) systems. Also, at low initial concentrations (100 and 500 ppb) a better adsorption phenomenon (i.e. WHO guidelines limit of 10 ppb) for the As(v) species onto the Ni-Al-Fe adsorbent was observed. In addition the kinetics of adsorption, and effect of concentration and pH on the adsorption phenomena have been detailed.