Aquaculture: High Intensity UV for Disinfection

To protect fish farms and hatcheries from outbreaks of water-borne diseases, water treatment specialist Hanovia Limited has developed a high intensity UV disinfection system.

Capable of treating up to 700m3/hr of both fresh or sea water with at least a 99.99% kill rate, the UV system can be used to treat both incoming and recirculation water, allowing flexibility in the choice of site and a rapid payback for farmers.

Increased water extraction and lowered water quality can result in increased outbreaks of viral and bacterial fish diseases. Due to the intensive nature of fish farming, fish stock is also highly susceptible to infection from natural fish populations in the water feeding the farm. To break the infection cycle between fish farms and natural fish populations, a disinfection system is needed to treat water entering and circulating within fish farms.

UV is ideally suited for these applications as it uses no chemicals and does not create by-products which would harm the fish stock, or other aquatic life, on discharge. Unlike other treatment methods, UV avoids the expense of complex monitoring systems involved in adding and removing chemicals before the water reaches the fish. In addition, it does not alter the pH of the water. Indeed, UV is the most economical disinfection technique that can be used in fish aquaculture.

Applications include treatment of water in hatcheries, shell-fish purging tanks and fry rearing tanks, and recirculation water in marine parks and aquaria.

Maintenance of the system is restricted to the replacement of the UV lamp every 12 months, a simple operation that can be carried out by on-site staff. An automatic or manual wiper can be fitted over the quartz sleeve which surrounds the UV lamp to prevent the build-up of any deposits, ensuring maximum levels of irradiation at all times.

A significant feature of the Hanovia system is the new Photon control panel which displays a range of useful functions such as flow rate, UV dose and intensity. It is capable of logging up to one year's performance data, which can be downloaded to a PC through an RS232 port.

Linked into a central computer, the control panel can also be operated remotely, and allows the system to operate around the clock.

To date Hanovia has installed over 300 aquaculture systems in 14 countries around the world. Applications include water treatment in hatcheries, fish farms (salmon, sea bream and sea bass) shellfish depuration tanks and fry rearing tanks as well as treating re-circulation water in marine parks and aquaria.