NOVELTY - Sludge is provided to a reaction vessel equipped with a microorganism support (MS), on a microorganism carrier plugger. A tube supplies air to bottom of MS. A inflow pipe connected to inflow mechanism regulates sludge flow. A circulation promotion mechanism comprising electrode for measuring pH and dissolved oxygen, circulates treated sludge, inducing a turbulent flow, for precipitation of sludge.    USE - For biological treatment of sewage sludge such as industrial waste, live-stock waste and domestic organic waste.    ADVANTAGE - The organic sludge is treated and microorganism in culture is activated efficiently. Automatic control of aeration and circulation of sludge is enabled based on the dissolved oxygen value so that the treated sludge has the target pH and dissolved oxygen content. Microorganism culture in the incubator part, and the decomposition of the sludge, are performed reliably. Continuous automatic operation of the apparatus is enabled. The inflow of sludge, and circulation and convection flow of treated sludge, are performed independently and efficiency of the apparatus is improved remarkably.    DETAILED DESCRIPTION - Organic sludge containing sewage and other waste material is provided to a reaction vessel (3). The vessel is equipped with a microorganism support with a microorganism support plugger (6), at the bottom. The microorganism carrier is cylindrical in shape and is separated from the walls of the reaction vessel (6c) at a predetermined gap, by a cover and a net (6a) partition. A diffusion tube (7) is arranged under the microorganism support plugger. Air is supplied through the diffusion tube to bottom of the support. The air pipe extends outside the reaction vessel to an aeration mechanism. Air from a blower (12) is sent into the reaction vessel. A sludge inflow pipe (14) connects to inside the reaction vessel, from a sludge inflow mechanism (13), which regulates the sludge inflow.    The inflow pipe delivers the sludge to the bottom of the microorganism support. Outside the reaction vessel, a sludge circulating mechanism (16) comprising a flow regulating valve (18) and a pump (19), enables the upward circulation of the sludge. The microorganism support comprises an air bubble guiding wall (6d), at the lower part, near the sidewall of the microorganism support plugger. The flow of the sludge solution is guided along with air bubbles generated from the diffusion tube. The sludge, after passing through the microorganism support, is returned by the circulating mechanism to a waste water take-off (21a) and a water sprinkling pipe (21c) ejects the sludge solution into the bottom spherical part of the reaction vessel. Then, the treated sludge liquid is made to circulate externally through the reaction vessel. A sludge circulation promotion mechanism (21) comprising a pump and a circulation type pH/DO electrode (22) for measuring the pH and dissolved oxygen (DO) value of treated sludge liquid, is provided in the middle of the sludge circulation route. The sludge solution is pressurized by the pump for circulation and is sprayed to the bottom of the vessel, inducing a turbulent flow, causing stirring of the sludge, aeration and precipitation to the bottom of the vessel as compact fine deposits. The final wash down of the sludge is carried out to the lowest part of the reaction vessel through the gap between the reaction vessel and side wall of the microorganism support plugger. The circulation convection of the sludge is performed effectively, before compaction.    DESCRIPTION OF DRAWING(S) - The figure shows vertical sectional drawing of microorganism culture apparatus for sewage treatment.    Incubator (1)    Operation control device housing ((2)    Reaction vessel (3)    Sludge inflow pipe (4a)    Sludge discharge (5)    Cylindrical side wall of support (6c)    Microorganism support plugger (6)    Air bubble guiding wall (6d)    Wire net for flotation prevention of microorganism support (6e)    Diffusion tube (7)    Aeration mechanism (9)    Air supply pipe (10)    Air flow regulating valve (11)    Blower (12)    Sludge inflow pipe (14)    Inflow valve (15)    Sludge discharge unit (16)    Sludge circulating mechanism (16)    Sludge discharge control valve (18)    Sludge discharge pump (19)    Control apparatus (20)    Circulation convection promoting mechanism (21)    Waste water takeoff (21a)    Water sprinkling pipe (21c)    Circulating type pH/DO electrode (22)