This study aims to remove of Cu2+, Cd2+, and Pb2+ ions from solution and to investigate the adsorption isotherms, adsorption kinetics, and ion-exchange affinities of these metals using waste activated sludge (AS) biomass. The adsorptions of the metals on biomass were optimal at an acidic pH value of 6.0 based on its monolayer capacities. Maximum monolayer capacities of AS biomass (qmax) were calculated as 0.478, 0.358, and 0.280?mmol?g-1 for Cu2+, Cd2+, and Pb2+, respectively, and the adsorption equilibrium time was found as 60?min for each metal. The adsorbed amount of metal rose with increasing of initial metal ion concentration. The equilibrium adsorption capacity of AS for initial 0.25?mmol?L-1 metal concentration was determined as 0.200, 0.167, and 0.155?mmol?g-1 for Cu2+, Cd2+, and Pb2+ ions, respectively. These relevant values were determined as 0.420, 0.305, and 0.282?mmol?g-1 for Cu2+, Cd2+, and Pb2+ ions, respectively, when initial metal concentration was 0.50?mmol?L-1. In the multi-metal sorption system, the adsorption capacity of AS biomass was observed in the order of Cu2+?>?Cd2+?>?Pb2+. In the presence of 100?mmol?L-1 H+ ion, the order of ion-exchange affinity with H+ was found as Cu2+?>?Cd2+?>?Pb2+. The adsorption kinetics were also found to be well described by the pseudo-second-order and intraparticle diffusion models. Two different rate constants were obtained as ki1 and ki2 and ki1 (first stage) was found to be higher than ki2 (second stage).