Abstract: A method and a system for enriching the oxygen content of a body water having a relatively low oxygen content are disclosed. The method contemplates providing, in a pipeline communicating with the body of water, a pressurized, flowing aqueous liquid stream that is at a pressure greater than ambient and supersaturated with respective to the dissolved oxygen concentration thereof. The liquid stream is maintained substantially free of bubbles which grow in size under conditions existing in the body of water. The flow rate of the oxygen-enriched aqueous liquid stream is modulated so as to maintain a dimensionless number, defined as: ##EQU1## wherein .rho.=density of the pressurized aqueous liquid within the pipeline,D=internal diameter of the pipeline,V=mean liquid velocity of the pressurized aqueous liquid stream within the pipeline,g.sub.c =gravitational constant,.DELTA.

Abstract: A continuous process for removal of ammoniacal nitrogen from water is disclosed. This process is useful for maintaining water quality in aquaculture operations, e.g., fish hatcheries and the like. A particulate stream of zeolitic ion exchange material is circulated continuously through an exchanger and a regenerator. An aqueous process stream containing ammoniacal nitrogen, e.g., ammonia, is passed through the exchanger in continuous counter current liquid-solid contact with a stream of particulate, ammoniacal nitrogen-sorbing zeolitic ion exchange material of natural or synthetic origin. A treated liquid water stream having a reduced ammoniacal nitrogen content exits from the exchanger, as does a stream of ammoniacal nitrogen-enriched particulate zeolitic ion exchange material. The latter stream is regenerated in the regenerator at a temperature of about 350.degree. C. to about 650.degree. C. while an oxygen-containing gas stream, e.g.