Abstract:The adsorption of copper (Cu) ion from aqueous solution with waste poplar leaves powder as an effective bioadsorption material was studied by differential pulse voltammetry (DPV). The limit of detection was found 2.5×10-8 mol/L for Cu ion solution in the concentration range of 2.5×10-4 – 2.5×10-7mol/L in 0.025 mol/L KCl solution. The effects of temperature,adsorption time, and the amount of poplar leaf powder on the adsorption of Cu ion were investigated. In 40 mL of 0.025mol/L KCl solution containing 2.5×10-4 mol/L copper ions, 0.1 g of poplar leaf powder adsorbed nearly 99% of Cu ions while 0.3 g of popular leaf powder completely adsorbed Cu ions. With the apparent first order adsorption rate constant of 0.00437 s-1，equilibrium state was reached in about 5 mins. The adsorption followed Temkin isothermal adsorption model with negative temperature effect. The maximum adsorption capacityis about 63.48 mg/g which may be exploited to remove Cu ions from the pollution water in natural pH condition.for adsorption removal treatments.