Charcoal Ash as an Adsorbent for Ni(II) Adsorption and Its Application for Wastewater Treatment

The aim of present research is to investigate sorption characteristic of nanoadsobent charcoal ash (ash) for the removal of Ni(II) from aqueous solutions and wastewater. The sorption of Ni(II) is carried out by batch method. The optimum conditions of sorption were found to be as follows: a sorbent amount of 3 g in 100 mL of aqueous solutions, contact time of 120 mm, and pH 4. In optimum conditions, removal efficiency was 94.2 % for the Ni(II). Three equations, i.e., Morris-Weber, Lagergren, and pseudo second order, have been tested to track the kinetics of the removal process. The Langmuir, Freundlich, and D-R are subjected to sorption data to estimate sorption capacity. It can be concluded that ash has the potential to remove Ni(II) ions from aqueous solutions at different concentrations. Desorption efficiency had been tested by water saturated with CO2 and by aqueous solution of NaOH, and the results were not considerable. The effect of temperature has been studied; it was found that increasing temperature has a positive effect on the adsorption, and the thermodynamic parameters Delta H, Delta S, and Delta G are evaluated. Thermodynamic parameters showed that the adsorption of Ni(II) onto ash was feasible, spontaneous, and endothermic under the studied conditions. At the end, ash was used for plating wastewater treatment so that the results were considerable. The removal efficiency of COD, Cr, Ni(II), Zn(II), and color were 68.3, 75.4, 91.5, 92.8, and 63.5 %, respectively. In this paper, different parameter such as pH, temperature, etc. were studied for Ni(II) adsorption onto ash, meanwhile this adsorbent is used for real wastewater (plating wastewater) treatment.