Fe3O4 nanoparticles coated with varied amount of poly vinyl pyrrolidone (PVP) were successfully manufactured by a co-precipitation method. The synthesis route followed by calcination at 400 ºC led to evolution of crystalline cubic inverse spinel structure Fe3O4/PVP nanoparticles with excellent adsorptive properties owing to high surface area and pore volume. Adsorption study performed using Fe3O4/PVP (1g) as adsorbent since it shown high surface area and the highest pore volume. The highest adsorption was found at pH 6 using Fe3O4/PVP (1g) as adsorbent. The equilibrium time for Congo red dye...