Ni(II) is toxic for living organism at trace levels. Currently the Environmental Protection Agency (EPA) standard for Ni(II) in drinking water is 0.04 mg/L [1]. The adsorption of metal ions using magnetic nanoparticles is preferred due to their lower costs, have high adsorption capacities, durability and high efficiency, especially for metal ions with trace and ultra-trace concentration level [2]. In this study, an in-house synthesized Fe3O4 MNPs adsorbent was evaluated for its feasibility in the adsorption of Ni(II) metal ions from aqueous solutions. Adsorption experiments were investigated by kinetic and isotherm adsorption models
