Plant Engineering Division

Rotating Biological Contactor

Rotating Biological Contactor Rotating Biological Contactor Rotating Biological Contactor Rotating Biological Contactor

Products Introduction

The Rotating Biological Contactor” has gained great trust for its superior durability and wastewater purification function, and has made us a leading manufacturer. In the past 30 years of company development, we have improved our techniques and have continued to upgrade our products. Currently, we have developed and introduced new technology, such as a unit type, units for pretreatment purposes, etc. Our products can meet the requirements for various applications.

Principles of the Rotating Biological Contactor

Principles of the Rotating Biological ContactorIn the Rotating Biological Contactor, wastewater is purified using microorganism membranes which are attached to disks. The disks slowly rotate with approximately 40% of surface area submerged in the wastewater. By absorbing oxygen from the air and pollutants from the wastewater, the pollutants are decomposed aerobically. While new microorganisms are continuously increase on the disks, old microorganisms whose activation has declined drop off the disks.


Durable and reliable system design ensures stable performance over the long term and is easy to manage.
  1. 1.Easy Operation control, No Specialized Skills required
    Complicated control, such as adjustment of the return sludge volume and air blowing volume is not necessary. Easy operation control without high operational control skills and professional knowledge
  2. 2.About 60% reduced power consumption compared to conventional processes. A sharp reduction in running costs.

    An aeration blower which consumes much power is not required.
    Therefore, just enough power to rotate the disks slowly is sufficient.

    ▼Comparison of economic efficiency (Construction costs + power costs) treatment ability in the case of 10,000m3/day
    fig. Comparison of economic efficiency (Construction costs + motion costs) treatment ability in the case of 10,000m3/day
    Condition: Construction costs is within range of first sedimentation tank – aeration tank – last sedimentation tank, Total of machine purchase costs and total of construction costs (civil engineering / plumbing / electricity / installment)
  3. 3.Changes in water quality or volume do not cause bulking.

    Even with changes in water quality and volume, there is no deterioration of water treatment quality by bulking, such as activated sludge process, due to high shock absorbability.

    ▼Comparison of treatment ability to change of the amount of water influent
    fig. Comparison of treatment ability to changeof the amount of water influent
  4. 4.50% or less reduction of excess sludge volume.
    Easy sludge treatment

    Compared with the activated sludge process, the food chain is long and the volume of excess sludge produced is 50% less than the activated sludge process. Because of this, the sludge treatment is reduced.

    ▼Comparison of amount of sludge produced
    fig. Comparison of amount of sludge produced
  5. 5.An outstanding durable main shaft has been designed and introduced.
    A square axle is used in the main shaft for increased strength design. The surface of the square axle is coated with FRP, providing a fully anti-corrosive structure.
  6. 6.No broken shafts due to the introduction of the [Square Axle] and [Block type Disk Insertion Assembly System].
    Disks are in block form and multiple pieces are assembled and inserted on the square shaft. This basically differs from a frame which is directly welded on the shaft and prevents repeated fatigue and broken shafts.
  7. 7.Disks are made from high density polyethylene with excellent strength and durability.
    The disks are made from high density polyethylene and show superior shock resistance, chemical resistance and corrosion resistance.

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