DESIGN AND OPERATIONAL CONSIDERATIONS FOR AMMONIA REMOVAL FROM CENTRATE BY STEAM STRIPPING

The New York City Department of Environmental Protection (DEP) is undertaking a comprehensive program to evaluate technologies for removing total nitrogen (TN) from wastewater effluent. Recycle streams such as ammonia laden centrate from dewatering operations can represent a significant contribution of TN to a water pollution control plant. Removal of ammonia from centrate prior to recycle can, therefore, be a cost-effective method of achieving overall TN reduction.A one year test program was conducted to develop design and operation considerations for a fullscale facility to remove ammonia from centrate. The objectives of the program were to evaluate centrate pretreatment needs, requirements for system flexibility and redundancy, quality of end product, and methods to mitigate system fouling.The results of the program strongly indicate that removal of ammonia by steam stripping represents a reliable cost-effective process option with providing 90 percent removal of ammonia for total annual costs in the range of 0.01 to 0.02 per gallon of centrate treated.