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RAS biofilters

The quality of recirculated water is one of the critical factors affecting the efficiency and commercial success of a RAS fish farming process. Removal of solids aside, water nitrification and denitrification are crucial – these processes are handled by a RAS biofilter

Operating principle

Biofilters for RAS are an integral part of high-density fish farming operations. The purpose and characteristics:

  • Utilisation of ammonium compounds – the components of fish waste. If they become concentrated in a pool, the fish can be poisoned;
  • Biological removal of toxic formations without any risk to aquatic life;
  • Conversion of ammonium by nitrifying bacteria, for which the compound is food, into nitrite, followed by nitrate, which is safe for fish;
  • Productive cleaning of the aquatic environment of toxic compounds to promote the development and growth of valuable fish species;
  • The biofilter is loaded with a multi-component filter bed on the surface of which bacterial colonies form. The interaction of bacteria with oxygen activates oxidative processes which transform ammonium (NH4) into nitrite (NO2), which is transformed into nitrate (NO3).

Design features

Constant filtering medium volume bioremediation systems which feature an increased working area of up to 700 m2 per 1 m3 of the filter medium. The advantages:

  • Construction material: food-contact grade AISI 316 stainless steel;
  • Reliable and mobile design: each component is easy to handle and relatively quick to install on site;
  • Low electrical power costs compared to MBBR filters;
  • Additional water filtration step to remove microparticulates.

Euro Industry offers the purchase of a RAS biofilter, designed and manufactured for customer-specified operating conditions, as part of a comprehensive service:

  • The design of biological filters is based on the specifications and practical needs of the customer;
  • In-house manufacturing;
  • Delivery, installation, and commissioning;
  • Warranty and post-warranty service;
  • Operating and maintenance training for the site staff.