Abstract: Adsorption of Pb and Cd onto suspended particulate matter, which was obtained from the Nanhu Lake by filtrating with the membrane filter of 0.45 μm, was investigated. The results indicate that the adsorption of Pb onto suspended particulate matter is greater and faster than that of Cd. The adsorption amount of Cd and Pb onto suspended particulate matter increases linearly with the weight of suspended particulate matter. The adsorption amount of Cd onto suspended particulate matter increases with the growth of pH, but the adsorption amount of Pb onto suspended particulate matter increases dramatically when pH is no more than 6.25, and then drops quickly when pH is above 6.25. The results of adsorption experiments of Pb and Cd at different ionic intensities show the possible coexistence of electrostatic adsorption and specific adsorption of Pb and Cd onto suspended particulate matter.

Key words: suspended particulate matter, plumbum, cadmium, adsorption