▎ 摘　　要

NOVELTY - Medical wastewater multi-stage sterilization device is based on graphene nanotechnology and comprises sewage unit, which comprises a first-stage graphene nanocomposite grid (2), a second-stage graphene nanocomposite grid (3) and a third-stage graphene nanocomposite grid (4) in sequence along the water flow direction. The mesh numbers of the first, second and third-stage graphene nanocomposite grids are sequentially increased. A sterilization unit and the sewage unit are connected by a first stage water valve (7). The medical sewage enters the sterilization unit after passing through the third-stage graphene nanocomposite grid in turn. The sterilization unit sequentially includes a graphene photocatalytic sterilization tank (8), a graphene modified diatomite sterilization tank, an ultrasonic sterilization tank and a laser sterilization device in the water flow direction. USE - Medical wastewater multi-stage sterilization device. ADVANTAGE - The medical wastewater multi-stage sterilization device has killing or blocking effect of the pathogenic bacteria and parasitic eggs in various medical sewages more thorough than the traditional methods, and isperiodically cleaned, the use period is longer, and the process cost is reduced. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for performing multi-stage sterilization for medical sewage based on graphene nanotechnology, which involves passing medical sewage through a graphene nanocomposite grid with three orders of increasing mesh size to obtain a preliminary sterilized water body, sterilizing sterilized water body by graphene photocatalyst sterilization, graphene modified diatom ceramic composite material sterilization, ultrasonic sterilization, laser and near-infrared sterilization to obtain a final sterilized water body. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of medical wastewater multi-stage sterilization device. First-stage graphene nanocomposite grid (2) Second-stage graphene nanocomposite grid (3) Third-stage graphene nanocomposite grid (4) First stage water valve (7) Graphene photocatalytic sterilization tank (8)