The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 09, 2008
Filed:
Jun. 28, 2007
Motoharu Noguchi, Handa, JP;
Motoharu Noguchi, Handa, JP;
NGK Insulators, Ltd., Nagoya, JP;
Abstract
A method of cleaning a membrane in a membrane separation activated-sludge process. By the method, deposits adherent to the surface of a membrane used in a membrane separation activated-sludge process can be effectively scratched off and the membrane filtration rate can be prevented from decreasing. Membrane-cleaning particles () in which the surface to be in contact with the water to be treated has been hydrophilized and has a surface roughness of 100-2,500 μm are introduced into a bioreactor (). The particles are caused to flow by the lifting effect of air bubbles ejected from an aerator () or by the fluidizing effect of a fluidizing means to thereby cause the particles to scratch off deposits adherent to the surface of a separation membrane element (). In one embodiment, membrane-cleaning particles () which are non-porous or have closed cells are used. In another embodiment, membrane-cleaning particles () having an antibacterial ingredient, such as copper or silver, supported on the surface or in inner parts thereof are used. In a still another embodiment, the membrane-cleaning particles () are periodically brought into an anaerobic condition to remove microorganisms from the particle surface.