NOVELTY - Treating liquid manure or biogas plant reject biologically for removal of odor and/or removal of nitrogen, involves feeding slurry type matter from first bioreactor tank into a second bioreactor tank for microbiological process; where in the second bioreactor tank is initiated a microbiological process of slurry type matter with a worked-up microbe population, which replaces original microbe population of slurry type matter, and solid matter is removed from bottom of first and second bioreactor tanks on mechanical conveyor (10).    USE - For treating liquid manure or biogas plant reject biologically for removal of odor and/or removal of nitrogen.    ADVANTAGE - In this process, the buildup of odor is substantially lesser, and it is possible to raise the slurry's pH with a microbial treatment alone to the value of not less than 8,8. This, in turn, promotes the removal of nitrogen and reduces the number of chemical additions required in the removal of nitrogen. In this process, the ammonium content is reduced, which enables a reduction in the toxicity and product inhibition of ammonium and thus an enhancement of the biological process. The ability to enhance a process enables reducing a residence time of the process, where the size of bioreactor tanks can be reduced. During a biological aerobic process, the slurry becomes odorless and more fluid. Thus, the slurry is easy to feed in and expel out of the stripping column, nor does the air blasted through the column cause odor problems in the environment.    DETAILED DESCRIPTION - Treating liquid manure or biogas plant reject biologically for the removal of odor and/or the removal of nitrogen, involves collecting a slurry type matter in a supply tank (3), in which is performed the separation of coarse matter by sedimentation and/or by a sieve; feeding the slurry type matter from the supply tank into a first bioreactor tank for a microbiological process or its initiation; feeding the slurry type matter from the first bioreactor tank into a second bioreactor tank for a microbiological process; aerating the slurry type matter by blasting air through the slurry type matter present in the bioreactor tanks, where the second bioreactor tank is initiated a microbiological process of the slurry type matter with a worked-up microbe population, which substantially replaces the original microbe population of the slurry type matter, and that a solid matter is removed from the bottom of the first and second bioreactor tanks on a mechanical conveyor (10). An INDEPENDENT CLAIM is included for an apparatus for treating liquid manure or biogas plant reject biologically for the removal of odor and/or the removal of nitrogen comprising a supply tank (3) for collecting a slurry type matter and for the separation of coarse matter by sedimentation and/or by a sieve, a first bioreactor tank for a microbiological process or its initiation, a second bioreactor tank or several successive bioreactor tanks for a microbiological process, and aeration unit (2, 6, 7) for aerating the slurry type matter present in the bioreactor tanks, where the bioreactor tanks have a tapering V-shaped bottom provided with a mechanical conveyor for the removal of sedimenting solids.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view of apparatus.    Pump (1)    Air source (2)    Supply tank (3)    First bioreactor tank (5)    Pipe (6)    Header (7a) Discharge pump (16) Stripping column (16a) Equalization tank (7)