Abstract: The excess sludge driven from corn processing wastewater treatment station was applied to absorbinglead and cadmium. The factors affecting the adsorption including adsorption time, temperature, pH value, excess sludge mass and the coexisting of lead and cadmium were investigated and analyzed. The result shows the adsorption of lead and cadmium onto the sludge is a quick process and the temperature has a less effect on the adsorption of lead and cadmium onto the sludge. The optimal adsorption pH range of the system for lead or cadmium is from 4 to 8. The adsorption capacity of lead and cadmium onto the sludge increases with the sludge mass increasing; the optimal sludge mass for lead  adsorptionis 0.5 g/L, the optimal sludge mass for cadmium adsorption is differe nt for the different initial concentration of cadmium and the value is between 0.5 g/L and 2 g/L. In the coexisting adsorption system of lead and cadmium, lead coexisted has an inhibitory effect on the adsorption of cadmium and cadmium coexisted has little effect on the adsorption of lead.

Key words: excess activated sludge, lead, cadmium, adsorption, corn processing wastewater