Adsorption Removal of Copper and Nickel Ions from Wastewater by Ammonia Modified Cotton Stalks

Abstract

The ammonia modified cotton stalks (CS) were utilized to adsorb the Ni2+ and Cu2+ ions from wastewaters, and the effect parameters (i.e. pH, contact time, adsorbent dose, and temperature) were also investigated by batch adsorption experiments. The maximum uptake was attained, i.e., 99.4% and 98.8%, respectively, for nickel and copper ions, under the optimum conditions (adsorbent dose: 10 g/L; pH: 6.0 (Ni2+), 5.0 (Cu2+); t: 75min; T: 20 °C) when the initial concentration of heavy metal ions was 20 mg/L. The adsorption process of nickel and copper ions on ammonia modified CS was well described by the pseudo-second-order kinetic model.