The objective of this research is to investigate the effect of each of the average organic load, the mixed liquor suspended solids(MLSS) in aeration tank and the ratio of concentration of metal to the MLSS on removal of cadmium and lead in activated sludge unit. Bench scale unit was used to conduct this study. Four glasses container were used, one for monitoring and others for examination of specific doses of lead and cadmium (5,10,20)mg/l. The capacity of sludge for metal under conditions of study were calculated. Dynamic constant of removal was computed depending on the result of study demonstrated as Frendlich and Langmuir equations, it is clearly shown that the relationship between capacity of sludge for cadmium to organic load is strong at three initial doses while lead was less correlated at the upper initial doses. As a result concentration of metals doesn't affect the removal efficiency of organic material at the range of the organic load used.
Keywords: Cadmium, Lead, Activated sludge, Frendlich Equation, Langmuir Equation, Organic load