Abstract: The present invention generally relates to a water purification device designed to operate primarily on gravitational force. The device comprises an inlet chamber (102) for storing surface water; and a filtration chamber (104) placed beneath the inlet chamber housing: a first filter made up of a 1:3 mixture of zeolite and acid-fractionalized activated charcoal, supported on a cotton bed; a second filter (104B) consisting of powdered eggshell membrane mixed with zeolite and Fe3O4 nanoparticles in a 5:3:1 ratio; and a third filter (104C) composed of a mixture of eggshell membrane powder, zeolite, Fe3O4, and AgNO3 nanoparticles, all supported on a cotton bed in a 5:3:1:1 ratio; and an outlet (106) adjusted at a bottom section for collecting purified water. The surface water enters from a top of the filtration chamber and is subjected to gravitational force, leading it through the series of filters towards the outlet.