There are different UV disinfection systems you can choose for your aquaculture application or any other application. Read on for important factors to help you choose the right UV disinfection system.

Ensuring sufficient filtration before the UV treatment

UV disinfection is a very effective method against pathogens. However, in most cases, UV requires sufficient filtration before the treatment to remove large particles and solids that could be creating a shadowing effect for the potentially harmful microorganisms, hence preventing them from getting the necessary UV light exposure. The correct filtration method and pore size depend on a lot of factors such as the number of suspended solids, the flow rate, the type of intake water and the transmittance of the UV light.

UV transmittance describes the effectiveness of disinfection by measuring the percentage of light that passes through a sample of water at the wavelength of 254nm. UV can vary between brackish water, seawater, freshwater and the location of the intake.

Viruses and bacteria also vary in size and this should be taken into consideration when designing your pre-filtration solution. Especially, in the farming of salmon, there has been a growing demand for UF systems as it is capable of removing viruses and bacteria from the water up to 4log. Ultrafiltration and UV treatment combined are capable of creating a double barrier against diseases as they complement each other.

Correct sizing of the intake

The correct sizing of the Ultraviolet system is the most important factor for providing a highly protective firewall against microorganisms in the water treatment system intake. A UV water system should be correctly sized. The correct sizing involves multiple factors such as lamp technology, a correctly applied UV dose, and so on.

Applying the correct UV dose

Microorganisms are inactivated by UV irradiation by damaging their RNA and DNA, which prevents them from causing an infection. The inactivation ability is dependent on the UV dose applied, which is the product of the intensity of the UV light, UV transmittance through water and residence time. The absorbance of the DNA is high between a range of 200nm and 300nm which results in efficient disinfection at 254nm.

Choosing the best lamp technology

UV systems based on the amalgam low-pressure and high-output lamps provide monochromatic UV irradiation at about 253, 7 nm, which makes them popular in disinfection systems. UV irradiation based on low-pressure lamp technology can be used to destroy ozone residuals. The residuals are typically destroyed with UV between the wavelengths of 250nm and 260nm.

UV systems that are based on medium-pressure lamp technology supplying UV light at a wider spectrum are also available but not commonly used for disinfection in aquaculture that is land-based due to their high cost of operation.

Operational optimisation

When choosing good UV disinfection systems, it is important to look into the operational optimisation of the disinfection system. This is beneficial for different factors such as saving time, cost efficiency and increased security. It is important to look into how to run the system in an energy-efficient manner and maintain the required dose level.