Adsorption Behavior and Mechanism of the Bamboo-Charcoal for Cd(II)in Aqueous Solution

The adsorption behavior of the bamboo-charcoal for cadmium(Ⅱ)was studied in aqueous solution.Parameters studied include contact time,pH,mass of Absorbent,adsorption temperature,and initial concentration of cadmium in solution.Results showed that bamboo-charcoal could effectively remove cadmium from the aqueous solution.The bamboo-charcoal showed high adsorption ability for cadmium at a wide pH range(pH=3.0～6.5),The optima adsorption acidity of bamboo-charcoal for Cd(Ⅱ) is pH 5.7 in the HAc-NaAc medium.Adsorption decreased with adsorption temperature increases,which means that the adsorption process is an exothermic process.Research of kinetics showed that adsorption of the bamboo-charcoal for cadmium can deal with pseudo first-order reactions.The apparent adsorption rate constants were determined at different sizes.The adsorption behavior of the bamboo-carbon for cadmium(Ⅱ) obeys the Freundlich isotherm model.After the adsorption the bamboo-charcoal can be regenerated quantifiably with H2O and microwave heating,the percentages of regeneration reached up to 93 %.The bamboo-charcoal is the better Absorbing material for removing cadmium(Ⅱ)from an aqueous solution.