A magnetically separable nanomaterial Fe ₃O ₄–TiO ₂ was synthesized and characterized which was subsequently used for the removal of arsenic (V) from aqueous solutions. The surface morphology, magnetic properties, crystalline structure, thermal stability and Brunauer–Emmet–Teller surface area of the synthesized Fe ₃O ₄–TiO ₂ nanoparticles (NPs) are characterized by scanning electron microscope and high-resolution transmission electron microscope, vibrating sample magnetometry, X-ray diffractometer, thermogravimetric analysis and multi point function surface area analyzer. The saturation magnetization of Fe ₃O ₄–TiO ₂ NPs was determined to be 50.97 emu/g, which makes them superparamagnetic. The surface area of Fe ₃O ₄–TiO ₂ NPs was as much as 94.9 m ²/g. The main factors affecting adsorption efficiency, such as solution pH, reaction time, initial As(V) concentration and adsorbent concentration are investigated. When the adsorption isotherms were analyzed by the Langmuir, Freundlich and Dubinin-Radushkevich models, equilibrium data were found to be well represented by Freundlich isotherm, and adsorption on Fe ₃O ₄–TiO ₂ NPs fitted well with pseudo-second-order kinetic model. The maximum adsorption capacity of As(V) on Fe ₃O ₄–TiO ₂ NPs, calculated by the Freundlich model was determined at 11.434 µg/g. 1.0 g/L of Fe ₃O ₄–TiO ₂ NPs was efficient for complete removal of 100 µg/L As(V) in 1 h. Fe ₃O ₄–TiO ₂ NPs was also effective for 93% removal of 100 µg/L As(III). Matrix effect was determined using As(V)-contaminated well water. Successfull results were obtained for purification of real well water containing 137.12 µg/L As(V). Results show that Fe ₃O ₄–TiO ₂ NPs are promising adsorbents with an advantage of magnetic separation.