Abstract: The invention relates to a reactor for treatment of waste water for being subject to both anoxic/anaerobic and aerobic treatment within one single reactor volume. The anoxic/anaerobic reaction zone is separated from the aerobic reaction zone by a separator which also works as a hydrodynamic separator between the two reaction zones. The reactor makes it possible that the effluent water has a lower proportion of suspended solids and also that it produces less sludge than reactors of comparison. The reactor is further more energy efficient than prior art reactors. Several reactors according to the invention may be arranged in parallel so as for the inlet waste water may be treated in a modular way, and thus allowing the maintenance of the units to be facilitated.

Abstract: The invention relates to a reactor for treatment of waste water for being subject to both anoxic/anaerobic and aerobic treatment within one single reactor volume. The anoxic/anaerobic reaction zone is separated from the aerobic reaction zone by a separator which also works as a hydrodynamic separator between the two reaction zones. The reactor makes it possible that the effluent water has a lower proportion of suspended solids and also that it produces less sludge than reactors of comparison. The reactor is further more energy efficient than prior art reactors. Several reactors according to the invention may be arranged in parallel so as for the inlet waste water may be treated in a modular way, and thus allowing the maintenance of the units to be facilitated.