Innovation & Investment

Estimating biofilter size for RAS systems

Controlling total ammonia-nitrogen (TAN) concentrations is the primary concern when sizing a biofilter for use in a recirculating aquaculture system. Sizing decisions are best based on previous experience with a given biofilter media in a specific biofilter configuration. 

READ
Flow rate estimation for RAS
Article image for Flow rate estimation for RAS

Innovation & Investment

Flow rate estimation for RAS

The water quality in recirculating aquaculture systems is generally a function of the tank size, biomass, feed inputs and waste treatment efficiency. Adequate biofiltration can control the build-up of ammonia-nitrogen and nitrate-nitrogen in the systems. 

TAN, other water quality factors affect nitrification rates in biofilters
Article image for TAN, other water quality factors affect nitrification rates in biofilters

Responsibility

TAN, other water quality factors affect nitrification rates in biofilters

An important criterion when studying biofilters is the conversion rate of total ammonia nitrogen (TAN) to nitrate-nitrogen in production water. Although nitrification rates have been based on media surface areas, they do not always reflect the actual nitrification achieved. Volumetric TAN conversion rate is a direct measure based on filter volume. 

Unit processes in RAS systems
Article image for Unit processes in RAS systems

Innovation & Investment

Unit processes in RAS systems

For most effective use, water should have low turbidity and high U.V. transmittance, with ultraviolet dosage tuned to the target organisms. Low-pressure/high-output amalgam U.V. lamps are often used in RAS systems.