摘要:
The present invention relates to a novel approach for nitrate removal from a marine recirculating system (10) wherein high concentrations of sulfate found in seawater is used in combination with sludge (20) collected from fish growing tanks (12) to promote dissimilatory sulfate reduction to hydrogen sulfide. The sulfide is used as an electron source to promote autotrophic denitrification in an up-flow fix bed bioreactor (16), followed by nitrification in a nitrification unit (14). By utilizing the symbiotic relationship between the sulfate-reducing and sulfide-oxidizing bacterial community, nitrate accumulation is controlled in the recirculating water of the system thereby reducing water exchange in the marine recirculating system.
摘要:
The present invention relates to a two-stage biofilter reactor system for removing nitrogenous compounds from a recirculating aquaculture system. The system includes a aerobic nitrification unit and a downstream anaerobic denitrification unit, wherein both units have a mobile bed of suspended media whereon bacteria can grow and reduce nitrate and/or ammonia levels in the recirculating aquaculture system. Use of the two-stage system has the advantage of reducing the water exchange rates and consumption of salt when maintaining a saline effluent.
摘要:
A system and method for removal of phosphates from a closed loop estuarine or marine recirculating aquaculture system (RAS), involving denitrification in the presence of a media substrate for: 1) anaerobic nitrate, nitrite and ammonia removal and 2) sequestering of excess phosphate in the RAS. Phosphate is precipitated in or on the denitrifying biofilm formed on the media substrate as phosphate salts. The phosphate salt-containing media substrate can be removed from the RAS, the phosphates can be removed, and both the substrate and the phosphates can be reused or recycled.
摘要:
A system and method for removal of phosphates from a closed loop estuarine or marine recirculating aquaculture system (RAS), involving denitrification in the presence of a media substrate for: 1) anaerobic nitrate, nitrite and ammonia removal and 2) sequestering of excess phosphate in the RAS. Phosphate is precipitated in or on the denitrifying biofilm formed on the media substrate as phosphate salts. The phosphate salt-containing media substrate can be removed from the RAS, the phosphates can be removed, and both the substrate and the phosphates can be reused or recycled.