Competitive adsorption of Hg2+, Pb2+ and Co2+ ions on polyacrylamide/attapulgite

► PAM/ATP displays an affinity order of Hg2+>Pb2+>Co2+ in binary and ternary system. ► The equilibrium behaviors can be described by the Langmuir equation. ► The adsorption kinetics fits pseudo-second-order kinetic model. ► The regenerated adsorbents could be reused with little loss of adsorption capacity.