A system and method is described having a single reaction vessel (12) using superheated stream optionally augmented by oxygen for reducing nitrogen oxides present in a wide variety of organic compounds. Reduction takes place quickly when a stream/oxygen mixture is injected into a fluidized bed (22) of ceramic beads. Reducing additives are metered into the reaction vessel (12) and/or provide energy input to reduce nitrates to nitrogen. The speed of the fluidizing gas mixture agitates the beads that then help to break up solid wastes and to allow self-cleaning through abrasion thereby eliminating agglomerates, and the oxygen, when used, allows for some oxidation of waste by-products and provides an additional offset for thermal requirements of operation.