Abstract: Bamboo charcoal (BC) was treated with KMnO₄ solution under refluxing condition to prepare the new modified bamboo charcoal.The influence of KMnO₄concentration on the Cu²⁺ adsorption rate-pH curves and pH₅₀ was investigated.The modification with KMnO₄ affected the adsorption and desorption capacity of bamboo charcoal to Cu²⁺.The results show that the Cu²⁺ adsorption rate-pH curves and pH50 of bamboo charcoal move to low pH after modification with KMnO₄.The best result achieved at 0.04 mol/L KMnO₄.The modification with KMnO₄ improves the adsorption rate of Cu²⁺ and reduces the consumption of adsorbent about threefold than that of unmodified bamboo charcoal.The adsorption isothermals of Cu²⁺ over the modified and unmodified bamboo charcoal match to Langmuir monolayer adsorption.On the same condition of equilibrium concentration of Cu²⁺, the adsorption amount of Cu²⁺ over bamboo charcoal modified with KMnO₄ increases about 53% than that of the unmodified bamboo charcoal.Moreover, the Cu²⁺ adsorption capacity of the modified bamboo charcoal can be improved obviously with the increase of temperature.At 40 ℃, the saturated adsorption amount of Cu²⁺ is 169% as much as that of at 25 ℃.The modification of bamboo charcoal with KMnO₄ not only increases the adsorption capability of bamboo charcoal to heavy metal ions, but also improves the ability of desorption-regeneration of bamboo charcoal.

Key words: KMnO₄, Modification, Bamboo charcoal, Adsorption, Cu²⁺