Ceramic filters with pores were created by sintering composite nano powders made of HAp and silica. They allowed drinking-water quality water to pass through them . Ag3PO4/HAP composites, which can be utilised as a material for water treatment, were easily made by in-situ precipitating Ag3PO4 on the pre-existing HAP nanowires . Hap has been produced using eggshells using different routes. [51-54].