A Cutting Edge Denitrification System for Complete Water Recirculation at a Mexico Fish Hatchery
Aquaneering Denitrification System
In a typical recycled aquaculture system, the oxidation of ammonia in the biofilters will cause nitrate to build up to the point of being detrimental to animal health. The general solution to this problem is a water change, but regulations in locations affected by drought now limit the amount of water available. In addition, regulations limit nitrate discharge concentrations under many conditions. These discharges to control nitrate concentrations also discharge any salts that have been added to the recycle system water, as well as alkalinity added to neutralize the nitrate being created.
Enter the denitrification system. Denitrification systems have been in use for several decades, primarily in wastewater treatment, but have not been traditionally used in aquaculture and aquatic filtration systems.
Dallas Weaver, Ph.D. and the Aquaneering
production team testing the denitrification system
The denitrification system currently being developed by Aquaneering reduces nitrate to nitrogen gas and then uses an aerobic fluidized bed to oxidize any residuals from the anaerobic denitrification reaction. This system will be used to process and recycle the high nitrate wastewater for a striped bass hatchery in Ensenada, Mexico. The system will support brood stock and fingerlings for production, which will be released to pens in the Pacific at a certain age and size for grow-out.
The unique design is a collaboration between Dallas Weaver, Ph.D., of Scientific Hatcheries, and Mark Francis of Aquaneering. The system will process 60 to 120 tons of water per day, providing nitrate-free return water and eliminating an equal volume of total water demand.
Protein Skimmer
The main anaerobic reactor is a specially designed fluidized bed bioreactor (FBB) with an atmosphere controlled packed column for removing the nitrogen produced, without
adding oxygen to the water. Bacteria growing on the sand media will reduce the nitrate to nitrite and then to nitrogen gas. As some potentially toxic compounds and residual ammonia are often formed under anaerobic microbiological conditions, this anaerobic system discharge will be treated with a high-performance aerobic fluidized bed biofilter and “protein skimmer” to control colloidal solids and surface active agents. The overall system is tied into a SCADA system for alarming and remote notifications. This particular design is skid mounted for easy installation.
The Ensenada hatchery will have recirculating water and zero discharge in an environment with a very limited water supply. The end result: protecting precious resources and supporting fish hatcheries through technological innovation.
Working Together is Success...
12th Annual Zebrafish Husbandry Workshop at Aquaculture America 2016
Dante D'India of Harvard University giving his talk on Improved Long-term Imaging of Embryos with Genetically Encoded a-Bungarotoxin
The 12th Annual Zebrafish Husbandry Workshop, in conjunction with the 2016 Aquaculture America Conference, was held in Las Vegas this past February. Attendance at the Workshop matched the previous all-time high and attendee participation surpassed previous years, making this an exciting and informative event.
Marc Tye, President of ZHA,
presenting Dr. Hugh Hammer of
Gadsden State with the Zebrafish
Stewardship Award
In addition to the Zebrafish Husbandry Association (ZHA) pre-workshop annual meeting and sponsored session, a new topic focus was introduced: a session on regulatory
issues organized by Monte Matthews. Matthews not only
received 105 completed online questionnaires prior to the workshop (designed to gauge community interest and quantify the most pressing concerns), but there was also spirited participation from the audience during the panel session.
Zebrafish Husbandry Workshop at Aquaculture
America 2016
Continuing the theme of working to integrate the husbandry and PI communities, the Workshop was honored to feature Dr. Stephen C. Ekker as the Keynote Speaker. Dr. Ekker is Professor of Biochemistry and Molecular Biology and Associate Director of the Clinical and Translational Sciences graduate program at the Mayo Clinic in Rochester, Minnesota, and Editor-in-Chief of the Zebrafish journal with the regular Fish Haus section that focuses on the science of fish husbandry (and currently organizing a Special Issue on Zebrafish Health for 2016). Dr. Ekker and other investigators participated in the Town Hall meeting after the workshop proper, coming up with action items to continue advancing the positive relationship between all members of the zebrafish research community.
Did You Know?
FAQs
Why isn't the pH probe calibrating or reading correctly?
Check the glass tip of the electrode. If it is broken, replace the electrode.
Check for water between the pre-amp and the electrode. If there is water present, dry out the pre-amp and electrode thoroughly.
Check for loose wires. Make sure all electrical connections are secure.
If you need to order a new pH electrode, visit the Aquaneering Online Store. (If your system has a gray twist-lock electrode, contact Aquaneering to discuss replacement options.)
The World Aquaculture Society's annual meeting will be held in San Diego next spring! We look forward to seeing you all there. Get all the details, full schedule, and registration information here.
