Patent ID: 7462284
Filing Date: 2008-12-09
Classification: A01K,C02F,Y10S

Abstract:
1. A method for reducing and/or removing nitrogenous products from a marine recirculating aquaculture system, the method comprising: housing an aquatic species in a rearing tank containing salt water medium, wherein the salt water medium comprises sulfates and is contaminated with at least ammonia and nitrates; transferring the salt water medium from the rearing tank through a downstream filter for separating solid materials from the salt water medium; transferring separated solids and at least some of the salt water medium to a sludge holding tank, wherein the sludge holding tank comprises a media substrate for growth of anaerobic microorganisms active in sulfate reduction; retaining the separated sludge and salt water medium in the sludge holding tank a sufficient time for generating sulfides through metabolic reduction of sulfate in the salt water medium by the anaerobic microorganisms active in sulfate reduction; transferring the salt water medium comprising the sulfides from the sludge holding tank to a denitrification unit positioned downstream from the sludge tank, wherein the denitrification unit comprises a fixed bed of media substrate for growth of anaerobic microorganisms active in sulfide oxidization and nitrate reduction; retaining the salt water medium in the denitrification unit for a sufficient time for oxidizing sulfides to sulfates and reducing nitrates to nitrogen gas by the microorganisms active in sulfide oxidization and nitrate reduction; transferring the salt water medium from the denitrification unit to a nitrifying moving bed bioreactor (MBB) positioned downstream from the denitrification unit, wherein the MBB comprises moving suspended media substrate for growth of aerobic microorganisms active in nitrification; retaining the salt water medium in the MBB for a sufficient time to reduce ammonia concentration in the salt water medium; and transferring the salt water medium from the MBB to the rearing tank for recirculation.