Use of curdlan and activated carbon composed adsorbents for heavy metal removal

Porous particles composed of curdlan and activated carbon mixture were developed to remove heavy metals from aqueous solution. The pore size was successfully controlled with the activated carbon to curdlan ratio. With pre-treatment of curdlan using acidic and alkaline solutions, the strength of the developed particles was increased. However, the adsorption capacity was decreased due to the residual sodium chloride produced from neutralization. The adsorption capacity for heavy metals was sufficiently high to remove these from the solution. The maximum heavy metal adsorption capacities for Cu(II), Mn(II), Pb(ll), and Cd(II) were 161 mg/g of adsorbent, 75, 72, and 41 mg/g, respectively. This result showed that the developed adsorption particles can be used for removing heavy metals from oriental herbs, especially those used in traditional oriental medicine. (C) 2004 Elsevier Ltd. All rights reserved.