NOVELTY - Magnesium ions are added to water (1) containing phosphorus and ammonia, stored in an aerobic treatment tank (3) in which microbes are floating, or are adhered to a fixed carrier. Magnesium-ammonium phosphate is precipitated in the tank, when the microbes oxidize a portion of ammonia, to nitrous acid. A membrane separator (9) or a dynamic filtration film is used to separate the precipitate and the microbes.    USE - For processing water containing phosphorus and ammonia, such as organic waste water obtained from methane fermentation tank, waste water obtained by dehydration and anaerobic treatment of organic sludge, industrial waste water, and biological waste water.    ADVANTAGE - Prevents the need to use a separate tank for producing magnesium-ammonium phosphate crystals, and nitrous acid, as the pH of the tank is held at a suitable level. Removes ammonia efficiently in the anaerobic treatment tank. Prevents draining of the microbes and the crystals from the aerobic treatment tank, by use of the membrane separator.    DETAILED DESCRIPTION - Magnesium ions are added to water (1) containing phosphorus and ammonia, stored in an aerobic treatment tank (3) in which microbes are floating, or are adhered to a fixed carrier. Magnesium-ammonium phosphate is precipitated in the tank, when the microbes oxidize a portion of ammonia, to nitrous acid. A membrane separator (9) or a dynamic filtration film is used to separate the precipitate and the microbes. The effluent of the aerobic treatment tank, is supplied to an anaerobic treatment tank (10) having autotrophic denitrification microbes, in which ammonia is biologically reacted with nitrous acid, and is oxidized so as to produce nitrogen gas (12).    An INDEPENDENT CLAIM is also included for processing apparatus of phosphorus and ammonia-containing water.    DESCRIPTION OF DRAWING(S) - The figure shows the schematic view of the processing apparatus for water containing phosphorus and ammonia. (Drawing includes non-English language text).    water containing ammonia and phosphorus (1)    aerobic treatment tank (3)    membrane separator (9)    anaerobic treatment tank (10)    nitrogen gas (12)