Preparation and characterization of carbons based on dates stones: Application to the adsorption of Zn2+ and Cu2+ ions

Abstract

The subject of this work is, as a first step, to prepare and characterize the adsorbents which are: the raw carbon, carbonized carbon and activated carbon from dates stones. In a second time, to determine the optimal conditions of operational parameters (time and temperature) of pyrolysis for carbonized carbon and adsorbents mass, contact time, agitation time, pH, and temperature in the adsorption  of Zn²⁺and Cu²⁺ ions of liquid effluents from hot dip galvanizing. During the treatment of these effluents, we have shown that the elimination efficiency of metals increases as the amount of adsorbent increases as we have been able to achieve significant yields for the removal of metal ions, in this case 96.17% for Zn²⁺ and 94.4% for Cu²⁺ in the case of activated carbon adsorption. However, we obtained a removal of 85.10% for the Zn²⁺ and 86% for the Cu²⁺ successively in the case of adsorption on carbonized carbon. Thus, we have seen only a removal of 70% for Zn²⁺ and 69.5% for Cu²⁺ in the case of raw carbon adsorption under optimal conditions, namely: pyrolysis temperatures (T=600°C and pyrolysis time is 3h) for carbonized carbon, the masses of the carbon equal 0.5g/L for the three carbons, contact time at 180min, pH about 6 and temperature equal to 30°C.