Kinetics of removal of hexavalent chromium from aqueous solution using an eco-friendly activated carbon adsorbent 

By Renuga Devi N, Manjusha.K and Lalitha P 


One   of the heavy metals that have been a major focus in water and waste water treatment- has been studied by adsorption technique. The pods of Delonix regia were used for preparing low cost activated carbon/ adsorbent and used in the removal of hexavalent chromium from aqueous solution. The optimum time required for the adsorption process has been evaluated. The kinetic of the process has been calculated using Lagergren’s first order equation. The results demonstrate that the carbon derived from the Delonix regia pods can be used as an efficient adsorbent for the removal of toxic Cr(VI) from aqueous solution. The adsorption of Cr(VI) was found to be time and concentration dependent. Maximum Cr(VI) removal (˜ 66%) was achieved with just 100mg of the adsorbent with an optimum contact time of 180 minutes at pH~4 when the initial concentration of Cr(VI) solution was 0.06 mg/l. Confirmation of data to the Lagergren’s rate equation indicates first order kinetics. 

Keywords: activated carbon, adsorption, hexavalent chromium, first order kinetics , Lagergren equation. 

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