PHYSICO-CHEMICAL PROCESS FOR REMOVAL OF NITROGEN SPECIES FROM RECIRCULATED AQUACULTURE SYSTEMS

摘要

Processes for removing nitrogen species from fresh water or high salinity water recirculated aquaculture systems. The processes are based on physico-chemical treatments which are performed at ambient temperatures and at low pH values thus keeping the total ammonia nitrogen concentrations below a value which is considered detrimental for the growth or survival rate of cultured fish/shrimp.

主权项

1. A process for removing ammonia from a saline water recirculated aquaculture system (RAS) while maintaining a total ammonia nitrogen (TAN) concentration in the water in said system between 15 and 50 mgN/L, the process comprising the steps of:
a. maintaining the pH of the water in the RAS below 7.5 by adding an acid; b. extracting a portion of the water from the RAS; c. oxidizing the ammonia in the portion of the water to nitrogen gas by electrochemical treatment or by breakpoint chlorination in the presence of a solution comprising Cl2 at concentrations required for attaining breakpoint chlorination;