Comparison of activated and inactivated coconut husk as an adsorbent for removal of hexavalent chromium from wastewater

Smita M. Honnannavar and Siddu

Abstract

The present study has been undertaken to evaluate the potential of utilizing activated and inactivated adsorbent, to remove Cr (VI) from aqueous solutions through adsorption process. The adsorption of hexavalent chromium from aqueous medium by activated and inactivated coconut husk prepared by activation method was studied. The adsorbent which showed highest chromium (VI) removal was inactivated coconut husk. The influence of pH, contact time, adsorbent dosage and initial metal concentration on adsorption was investigated. The adsorptive capacities of the adsorbents were dependent on the pH of the chromium solution, with pH 2 being optimal. The adsorption data fitted well with the Langmuir isotherm model. The adsorption capacities were found to be 0.86mg/g for activated coconut husk and 1.781mg/g for inactivated coconut husk respectively. Hence it is proved that inactivated coconut husk has slightly more adsorption capacity when compared to activated coconut husk