Inter Aqua Advance

Recirculation fish farming since 1978


Clearwater Low-Space Denitrification Reactor








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The Clearwater Low-Space Denitrification Reactor

 -  State of the Art in Moving Bed Technology.


Our denitrification reactor designs are based on Clearwater Low-Space technology, providing optimal denitrification performance with a minimum of space requirement, maintenance and operational costs. 



















3rd Generation Clearwater Technology

·       Min. 4200 g NH3-N/m3/day turnover at 15 °C

·       Very large capacity with small footprint

·       No return activated sludge requirement

·       No backwash water requirement – sludge drained from conical bottom

·       Low maintenance

·       Enhanced self-cleaning capacity with Curler Advance X-1 Bio-Media



In recirculating aquaculture systems, high organic material (BOD) and nitrate concentrations can lead to undesirable oxygen consumption in the system channels. Although generally not considered toxic to aquatic species, nitrates will accumulate in the system and at high levels induce reduced appetite and stress. Denitrification is therefore required to prevent these undesirable effects.


In combination with nitrification units, a separate denitrification unit reduces the organic material concentrations, which lowers heterotrophic activity in the nitrification unit, thereby enhancing the pure nitrification efficiency.


In recirculating aquaculture systems, a denitrification unit also provides the benefit of reducing the amount of alkalinity that needs to be added to maintain water quality requirements.


Similar to the principles of a standard moving bed bio-reactor, the Clearwater Denitrification Reactor technology is based on a reactor in which specifically designed Curler Advance X1-110 bio-media is continuously agitated and provide a very large surface area for bacterial attachment and growth. By constantly providing a scouring effect from the force of movement on the bio-media, old and inactive bio-film layers are continuously exfoliated, maintaining a thin and highly active young layer of bacteria on the bio-media surface. This effect prevents inefficient utilization of the available media surface area due to excessive development of inactive bio-film layers and thereby makes the unit essentially self-cleaning.


The Clearwater technology allows units to be very compact and highly efficient with a very small footprint when compared to active sludge systems. We strongly recommend using the Curler Advance Bio-media that was specifically designed to fully exploit the denitrification reactor’s self-cleaning capacity and maintain a very large active surface area.


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