Adsorption of NI (II) on activated Carbon of Coconut shell Chemicaly Modifieded with Acid Nitric Solutions

Abstract

In the research the effect of modification of coconut shell activated carbon with diluted solutions of nitric acid, in its chemical characteristics and removal capacity of the nickel (II) ions present in modeling solutions of sulfates with similar characteristics to the acid liquor waste of the nickel industry, was studied. The characterization of the adsorbent material evidenced that the modification process increases the superficial acids groups according with the increase of acid nitric concentration employee in the treatment. The adsorption equilibrium tests, carried out with metallic species solutions at concentrations between 0,5 and 3,5 g/L evidenced that the process is described by Freundlich model. The effect of chemical modification of the adsorbent material in adsorption capacity of nickel (II) ions was evaluated using a traditional experimental design at pH of 1,2 and 6,9 units, obtaining that the increase of acid groups in the carbon surface causes an increase of adsorption capacity and removal percentages of nickel (II), due to specific interactions of these groups with the metal cations.