Nano-magnetite wasused as an eco-friendlysorbent (without the usage of surfactants during the synthesis) for removing Pb(II), Cd(II) and Cr(III) from water and wastewater. A single 7 nm cubic phasefor magnetitewas ascertained by X-Rays diffraction (XRD) and high resolution transmission electron microscope (HRTEM).Field emission scanning electron microscopy (FESEM) image showed the agglomeration of magnetite particles upon adsorption. The Langmuir isotherm was used to estimate themaximum adsorption capacities of 576.4, 144.3 and 301.0 mg/g for Pb(II), Cd(II) and Cr(III), respectively.The adsorption mechanism followed a pseudo-second order kinetics.The studied competing cations and anionsshowed minor effects on the rate of adsorption.Magnetite with high adsorption ability adsorbed Pb(II), Cd(II) and Cr(III) from a ternary mixture aseffectively as from their individual solutions. The presented sorbent can be regenerated by 1% HNO3 with a recovery percent of 91.4 % and reused with an adsorption efficiency of 84.1 % compared to the freshly prepared magnetite. As an example of application, the nano-magnetite was used to decontaminate river water-samples from lead ions.