Inorganic nitrogen removal in a combined tertiary treatment-marine aquaculture system. I. Removal efficiencies

Since nitrogen is the principal nutrient controlling algal growth in coastal waters, experiments have been carried out on removal of ammonia and nitrate from secondary sewage effluent by a 3-stage growth system containing marine phytoplankton, oysters and seaweeds. This system removed 95 per cent of total nitrogen and 45-60 per cent of phosphorus. The system could also be expanded if desired to include other trophic levels such as fish, and cooling water from power plants could be used to give year-round temperature control.