NOVELTY - Processing of organic wastewater involves preparing supernatant liquid (A) by dehydrating without adding polymer flocculant to the mixed sludge, preparing supernatant liquid (B) by dehydrating after adding polymer flocculant to the mixed sludge, after dehydrating the mixed sludge of excrement and/or organic sludge and surplus sludge generated from biological treatment. While adding polymer flocculant to supernatant liquid (B), magnesium-ammonium phosphate is collected from the supernatant liquid (B).    USE - Processing of organic wastewater for preparing magnesium ammonium phosphate used as compound fertilizer (claimed).    ADVANTAGE - Magnesium ammonium phosphate is recovered efficiently by processing organic wastewater. Since flocculant addition amount required for dehydration process and chemical addition amount required for biological treatment is reduced, the moisture content and generated dewatering cake are reduced.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) apparatus for processing organic wastewater, which consists of a mixing tank (10) for mixing excrement and/or organic sludge, and surplus sludge, a water-removal device (40) which is provided downstream from the mixing tank for spin-drying mixing sludge, an agglutination reaction tank (20) for adding polymer flocculant and aggregate, is provided between the mixing tank, bypass route for sending the mixing sludge to the water-removal device directly from the mixing tank without going through the agglutination reaction tank, magnesium-ammonium phosphate collection apparatus (80), supernatant liquid storage tank (50), biological treatment tank (60), and solid-liquid-separation tank (61) provided downstream from the biological treatment tank;    (2) manufacture of compound fertilizer; and    (3) apparatus for manufacturing compound fertilizer.    DESCRIPTION OF DRAWING(S) - The drawing shows a flowchart explaining the process of organic wastewater. (Drawing includes non-English language text)    Mixing tank (10)    Line mixer (11)    Agglutination reaction tank (20)    Water removal device (40)    Supernatant liquid storage tank (50)    Biological treatment tank (60)    Solid-liquid-separation tank (61)    Magnesium-ammonium phosphate collection apparatus (80)