Ammonia stripper apparatus and method

An apparatus 32 for stripping ammonia from ammonia-containing water, comprises an ammonia-containing water inlet (56, Fig. 2), steam inlet (70, Fig. 2), forced air inlet (82, Fig. 2), ammonia-containing gas outlet (36, Fig. 2) and a wastewater outlet (72, Fig. 2). The steam and air contact the ammonia-containing water in counter-flow to release ammonia from the water. A steam and air mixing duct 200 is shaped to create turbulence in the steam and air flow to promote mixing prior to contacting the ammonia-containing water. Other aspects involve pre-humidifying the air prior to mixing with the steam; locating a solids precipitation unit upstream of the ammonia-containing water inlet; locating a steam flash vessel downstream of the wastewater outlet for generating steam for recycling into the ammonia stripper; or returning ammonia-containing gas into the ammonia stripper to mix with the forced air entering the ammonia stripper. Further described are thermal destructors (16, Fig 5) for destroying ammonia in ammonia-containing gas from an ammonia stripper, wherein exhaust gas from the thermal destructor is recycled back into the destructor for further combustion or wherein exhaust gas is vented via an economiser (230, Fig. 6) for heat transfer to liquid entering the ammonia stripper.