Hi, There are several methods for separation of gaseous ammonia from water. This paper summarizes them well. http://www.academia.edu/4907207/AMMONIA_REMOVAL_FROM_WASTEWATER It isn't clear to me if you wish to collect the ammonia and contain it once separated from the water or if you simply are trying to remove it from the water. I'm also not sure what technology you have available to you. But a simple air bubbler may be sufficient for the job.