Biotechnology and Bioinformatics (1+1)

6.2.3. Characteristics of the "Ideal" biofilter

The following are the features of a good biofilter.

1. Small footprint - The biofilter should occupy as little space as possible. It is common to have culture tanks and the biofilters under cover for protection and temperature control. Space allocated for biofilters takes away area that could be used for culture tanks.

2. Inert materials of construct ion - All materials used in the biofilters should be non- corrodible, UV resistant, resistant to rot or decay and gene rally impervious to chemical attack. In general, marine grade construction materials are required for reasonable working lifetimes.

3. Low capital cost - The biofilter must be inexpensive to purchase or build and cheap to transport to the farm location.

4. Good mechanical strength - The biofilter and its components must be tough enough to withstand the normal wear and tear of a industrial/agricultural environment.

5. Low energy consumption - The energy cost (usually electricity) to operate the biofilters should be as low as possible. The largest energy users are the pumps to move water and compressors to move air.

6. Low maintenance requirements - The biofilters should be self cleaning with little or no care required for the normal life of the crop.

7. Portability - The biofilters should be easily movable to facilitate changes in operation of the facility.

8. Reliability - Ideally the biofilters should have no moving parts that could fail at an inopportune time. If the biofilters does have moving parts, they should be rugged and designed for a continuous operating life of several years.

9. Monitorability - It should be easy to observe the operation of the biofilter to insure that it is operating correctly.

10. Controllability - It should be easy to change operating variables to assure optimum performance.

11. Turndown ratio - The biofilters should be able to work under a wide range of water flow rates and nutrient loading levels.

12. Safety - The biofilters should not have any inherent dangers to either the crop or the owner/operator.

13. Utility - The biofilters should accomplish all of the goals i.e. removal of ammonia, carbon dioxide, BOD, suspended solids, etc.

14. Scalable - A small system should work the same way as a large system. The performance per unit volume should be constant regardless of the size of the system.