A water filtration membrane is provided, capable of removing heavy metal ions, filtering out particulates, filtering out bacteria, as well as removing herbicides and volatile organic compounds (VOCs) from water. The membrane is composed of a mat of randomly oriented nanoparticle-coated nanofibers. The nanofibers are covalently bonded to a plurality of substantially uniformly-distributed ceramic nanoparticles embedded in or adhered on the surface of the polymer nanofibers through reactive functional groups. The ceramic nanoparticles have a pattern of deep grooves formed on the nanoparticle surfaces. The bonding of the nanoparticles to the nanofibers is sufficient to retain the nanoparticles on the nanofiber surfaces when water flows through the water filtration membrane. The diameter of the nanofibers is 50-200 nm. The size of the nanoparticles is