Process and equipment for recycling ammonia nitrogen waste water

The invention relates to a process and equipment for recycling ammonia nitrogen waste water. The process comprises the following steps of: absorbing a gaseous film; crystallizing magnesium ammonium phosphate; separating a crystalline liquid; and recovering a crystalline mother liquid. The equipment comprises a raw water tank, a film contactor, an absorption tank, a crystallizing tank and a filter. According to the process and the equipment, waste water treatment and the recycle of ammonia nitrogen are integrated in the same process and equipment highly, and high-purity magnesium ammonium phosphate is obtained in low cost while waste water is treated efficiently, so the process and the equipment are suitable for large-scale industrial application and have a good market prospect.