Spherical assembly composed of MnO2 nanoparticles with an average diameter of 0.8-2.0 am have been prepared using spent Zn-Mn batteries. The product was characterized by X-ray powder diffraction and scanning electron microscope. The adsorption performance of spherical assembly composed of MnO2 for methyl red was investigated. The adsorbent showed high efficiency for the removal of methyl red in water. The equilibrium of adsorption was achieved within 30 min. The isotherm adsorption data obeyed the Langmuir...