This paper describes the use of two steelmaking industry by-products (rolling mill scale and blast furnace sludge) as adsorbents for removing heavy metals from aqueous effluent solutions. The adsorption of Pb2+, Zn2+ and Cd2+ on these materials has been studied by the determination of adsorption isotherms from solutions of controlled ionic strength. The effect of time, equilibrium temperature and metal solution concentration on adsorption efficiency was evaluated. The adsorption processes are analysed using the Langmuir theory. Desorption and dumping processes for the metals from loaded steelmaking industry by-products were also studied under different experimental conditions. The by-products were shown to be effective adsorbents for the studied cations in aqueous solutions within the range of working concentrations. (c) 2005 Society of Chemical Industry.