Adsorption of cadmium(II) from an aqueous solution onto activated carbon cloth

The effects of surface properties and solution pH and temperature oil the adsorption of cadmium(II) onto activated carbon fiber cloth (ACC) made from polyacrylonitrile (PAN) were investigated in this work. The ACC was oxidized with HNO3 solution and the concentration of acidic sites increased during oxidation whereas that of basic ones diminished. The adsorption capacity of the oxidized ACC was higher than that AA of ACC without oxidation because the ACC contained greater concentration of acidic sites. It was found that the maximum adsorption took place at pH 8 and the adsorption capacity increased near 22 times, augmenting the pH from 2 to 8. The adsorption capacity diminished on the average twofold, increasing the temperature front 15 to 35 degrees C. Cd(II) adsorbed on ACC at pH 6 can be almost completely desorbed by reducing the solution pH to 2. The adsorption capacity is considerably dependent upon the characteristics of the ACC surface and temperature and pH of the solution.