Adsorption of Cr (VI) from aqueous solution using activated carbon prepared from paper mill sludge by ZnCl2 activation

The activated carbon prepared from paper mill sludge was chemically activated using ZnCl2 and utilized as an adsorbent for the removal of Cr(VI) from aqueous solution. The sludge was activated with 5 M ZnCl2 solutionand pyrolyzed at 650°C for 1h at the heating rate of 10°C/min under an inert atmosphere. The product activatedcarbon was characterized in terms of microporosity and elemental composition. The produced adsorbent was showed BET surface area of 133.34 m2/g, total pore volume of 0.2525cm3/g, and mesoporosity of 52.0%. Eqilibrium adsorption experiments were carried out in a batch process to evaluate the capacity of the sobent forupatke of Cr(VI). The effect of adsorption Various experimental parameters such as PH, and carbon dosage on removal efficiency was studied. The maximum adsorption capacity of activated carbon was found to be 21.77 mg/g, at optimum conditions of pH 4 and carbon dosage of 3.5 g/L at temperature 30°C . Adsorption parameters were determined using Langmuir, Frendlich and Langmuir-Frendlich isotherms and it was found that the best fit was obtained by Langmuir-Frendlich models

Keywords:

Cr (VI) , Adsorption isotherm , activated carbon , aqueous solution