Updated: July 2002

1. Purpose

There are several processes for treatment of malodorous gas, such as absorption with active carbon, combustion and so on. A variety of deodorizing systems in their combination are also available. However, they have drawbacks of causing secondary pollution in waste disposal as well as troublesome maintenance, in general. Then, this biodeodorization equipment has been developed to solve those problems by decomposing malodorous gases with microorganism on woody carbon carriers.

2. Performance

Intensity value of malodor of gases decreases to lower than 2.5 of the regulated value by the Malodor prevention Act. Their odor concentration is reduced below 300.

3. Characteristics

1) To cope fully with malodorous gases of multicomponent systems and their concentration change.
2) Simple equipment almost free from maintenance management.
3) Extremely low operation cost just for small quantity of spraying water and blower power.
4) Harmonized with nature cycles by using microorganism, therefore, almost kept away from secondary pollution.

In addition, carriers of woody carbon suit microorganism to live, since they are porous, excellent in water holding and water permeability. It is another feature that their waste can be disposed by combustion.

4. Principle

Malodorous gas sent by a blower enters the deodorizing tower from its lower part and dissolves into water attached on the carrier surface, where gas is incorporated directly into the cell membrane of microorganism and is subjected to oxidative decomposition by enzymic action. Water to remove decomposed products and to be supplied to microorganism is sprayed onto the carrier surface intermittently by sprayers.

5. Figure (Flow sheet)

6. Application and Subject

Public facilities such as plants for treatment of night soil and sewage, for disposal of wastewater from farm villages.
Private sewerage system, building-pits.
Plants of food, feed and seafood processing industries.
Pretreatment of highly concentrated malodorous gas.

7. Example

Deodorizing equipment in night soil treatment plant of W city
Deodorizing equipment in sewage disposal plant of K prefecture
Deodorizing equipment in wastewater disposal plant of a farm-village in I prefecture
Desulfurization test equipment in H geothermal power plant