Mercury(II) adsorption by activated carbon made from sago waste

The preparation of activated carbon (AC) from sago industry waste is a promising way to produce a useful adsorbent for Hg (II) removal, as well as dispose of sago industry waste. The AC was prepared using sago industry waste with H2SO4 and (NH4)(2)S2O8 and physico-chemical properties of AC were investigated. Adsorptive removal of mercury (11) from aqueous solution onto AC prepared from sago industry waste has been studied under varying conditions of agitation time, metal ion concentration, adsorbent dose, particle size and pH to assess the kinetic and equilibrium parameters. Adsorption equilibrium was obtained in 105 min for 20 mg l(-1) and 120 min for 30, 40, and 50 mg l(-1) Hg (II) concentrations. The Langmuir and Freundlich equilibrium isotherm models were found to provide an excellent fitting of the adsorption data, with r(2) 0.9999 and 0.9839, respectively. The adsorption capacity of Hg (II) (Q(o)) obtained from the Langmuir equilibrium isotherm model was found to be 55.6 mg g(-1) at pH 5.0 for the particle size range of 125-250 mum. The percent removal increased with an increase in pH from 2 to 10. This adsorbent was found to be effective and economically attractive. (C) 2004 Published by Elsevier Ltd.