NOVELTY - A nitrogen-containing organic wastewater processing system comprises a floating sludge type biological-treatment apparatus (11), a membrane separator (12), and an anaerobic-organism fixed bed apparatus (13). Apparatus (11) performs biological treatment of organic wastewater, and performs nitrification of nitrogen component in wastewater. Separator performs membrane separation of biologically treated liquid. Apparatus (13) performs biological treatment of supernatant liquid, and performs denitrification of nitrogen component in supernatant liquid.    USE - For processing nitrogen-containing organic wastewater (claimed), such as human waste, purification tank sludge, industrial liquid waste, livestock farming wastewater, fish processed wastewater and detergent drain wastewater.    ADVANTAGE - The processing system reliably and efficiently enables processing of nitrogen-containing organic wastewater at high nitrogen removal efficiency.    DETAILED DESCRIPTION - The nitrogen-containing organic wastewater processing system comprises a floating sludge type biological-treatment apparatus (11), a membrane separator (12), and an anaerobic-organism fixed bed apparatus (13). The apparatus (11) carries out biological treatment of nitrogen-containing organic wastewater with activated sludge in floating state. The separator carries out membrane separation of biologically treated liquid ejected from apparatus (11), and obtains supernatant liquid and sludge. The apparatus (13) carries out biological treatment of supernatant liquid by effect of microorganism fixed to support under anaerobic condition. The apparatus (11) carries out nitrification of nitrogen component contained in organic wastewater. The apparatus (13) carries out denitrification of nitrogen component contained in supernatant liquid.    DESCRIPTION OF DRAWING(S) - The figure shows the outline block diagram of organic wastewater processing system. (Drawing includes non-English language text)    Pre-processing unit (10)    Floating sludge-type biological treatment apparatus (11)    Membrane separator (12)    Anaerobic organism fixed bed apparatus (13)    Sludge treatment equipment (14)