Bio-Filter

Biological filters are also known as bio filters. The biological filter systems are used to remove organic pollutants from wastewater, water, and air. The primary function of a biological filter is to create bacterias. Bacterias break down the harmful ammonia in the water deriving from fish faeces and other sources. Ammonia is broken into Nitrites which in turn breaks down to Nitrates. The biological filter had a dual function because it also filter debris.

Biological filters are the type of systems that creates the adequate type of bacterium, such as nitrosomonas and nitrobacter. These bacterias break down ammonia and nitrites. The biofilters usually contains a container with bio media inside. Bio media provides an ideal environment for the bacteria to grow inside the biofilters. The bio media contains a lot of air pocket which is ideal for the bacterias to grow.

Need of Biological Filters
Biofilters are used to help maintain the quality of water in recirculating or closed loop systems. They are also used to enhance the water quality before water is discharged from a facility. Biological filters are very important and essential component especially for recirculating aquaculture or aquarium systems.

Here are the list of functions performed by the biological filters. Some of them are performed by biological means and some by physical processes.

• Remove ammonia
• Remove nitrites
• Remove dissolved organic solids
• Add oxygen
• Remove carbon dioxide
• Remove excess nitrogen and other dissolved gasses
• Remove suspended solids

What to Look For in a Biofilter?
You must consider for some factors before purchasing a biofilter. Here are some characteristics that can be considered as a checklist that you can use to rate the biofilters.

• Low capital cost: The biofilter should be inexpensive to build or purchase. It should be cheap to transport to the farm location.
  
  
• Small Footprint: The biofilters should occupy as little space as possible. The have culture tanks and the biofilters under cover for protection and temperature control.
  
  
• Inert materials of construction: The materials used in the biofilters should be UV resistant, resistant to rot or decay, non-corrodible and generally impervious to chemical attack. Usually marine grade construction materials are used for reasonable working lifetimes.
  
  
• Good mechanical strength: The mechnical strength of the components of biofilter must be strong enough to resist the normal wear and tear of an agricultural or industrial environment.
  
  
• Reliability: If the biofilters have any moving parts, they must be rugged and designed for a continuous operating life. Ideally they should not have any moving parts that could fail at a wrong time.
  
  
• Monitorabilty: The biofilter should be easily monitorable so that it could be easy to observe the operation of the biofilter to insure that it is operating correctly.
  
  
• Low energy consumption: The biofilter should consume as low energy as possible. Pumps and compressors are the largest energy users.
  
  
• Low maintenance requirements: The maintenance requirements should be low. They should be self cleaning with little or no care needed.
  
  
• Controllability: It should be easy to change operating variables to assure optimum performance.
  
  
• Portability: They should be easily movable so that they can be changed in operation of the facility.