Application of O3 and BAC Process in Closed Recirculating Aquaculture System
|School||South China University of Technology|
|Keywords||Recirculating aquaculture system O3-BAC hyphenated techniques Ammonia Nitrite nitrogen|
Aquaculture wastewater containing mainly ammonia, nitrite nitrogen, organic pollutants and contaminants such as bait , with a large water feature , if not treated directly discharged into the environment , it will cause great environmental pollution. Polluted water environment , in turn, limits the development of aquaculture . Closed recirculating aquaculture is a green , pollution-free healthy farming methods , it appears to solve the problems caused by traditional farming to meet the development requirements of circular economy is the development direction of factory farming . Recirculating aquaculture system (RAS) is the core of water treatment technology . O3-BAC hyphenated technique is widely used in drinking water treatment , the less coverage for aquaculture wastewater treatment . Study O3 and BAC hyphenated techniques for closed loop water depth carp culture system processing . In aquaculture wastewater for the study, experimental studies have found , BAC filtration column best filtration rate and residence time of 4m · h -1 sup> and 30min, control water temperature, pH is relatively stable, to ensure adequate influent dissolved oxygen long enough residence time, and regular backwashing is the biological activated carbon filter column stable and efficient operation of the necessary conditions. Testing to determine ozone treatment of aquaculture wastewater optimum dosage of 1.0 mg · L -1 sup>, optimal residence time of 3 ~ 5min. Based on the above study established a small recirculating aquaculture systems , the study identifies a recirculating aquaculture system, the best circulation flow 270L / h, ie 1h 1 cycle . When the system operating parameters are: ( a ) circulating flow 270L / h; (2) ozone dosage 1.0 mg · L -1 sup>, ozone contact time 4min; (3) a sedimentation tank stay time of 4min; (4) grit chamber residence time is about 15min; (5) the water column in the BAC reactor residence time of carbon layer was 20min . Recirculating aquaculture system, pond water quality is good , to meet growing water demands carp . Comparative study of changing the water circulating aquaculture and traditional farming , the study found , changing the water aquaculture ponds traditionally a serious pollutant accumulation phenomenon , on the contrary , circulating water in the aquarium water stable, well , there is no accumulation of pollutants phenomenon , more suitable for fish growth and development. 30d feeding fish in aquarium water circulation after weight gain was 35.4% , while the traditional fish in aquarium water changes weight gain rate of only 11.7% .