Solution

PlanetDISK® RBC (Rotating Biological Contactor) Technology

After many successful implementations on 5 continents, PlanetDISK® has become the RBC brand name of reliable, robust, solid state on-location, decentralized biological waste water treatment for capacities between 200 – 20.000 people.

 

Technology Inspired by Nature

What makes PlanetDISK® so perfect is the shear simplicity behind its design and principle of how it works. This brings along simplicity in operation and maintenance.

How  PlanetDISK® Technology Works

  • The PlanetDISK® unit is a fixed film system in which disks constructed from corrosion-resistant, high-density polypropylene (HDPP) are arranged side by side on an epoxy-coated steel shaft and rotate at 3-4 revolutions per minute.
  • Prior to entering the Rotating Biological Contactor system, wastewater passes through an inlet structure that includes a screen and grease trap, followed by sedimentation tanks. In the biofilm method, bacteria retained on the disks consume only soluble BOD in the wastewater.
  • Approximately 40% of the disks on the shaft are submerged in wastewater. Bacteria developing on the disks (biological sludge) absorb oxygen required for oxidizing and processing organic matter as the disks rotate in and out of the wastewater, obtaining oxygen from the surrounding air. This process leads to an increase in bacterial population.
  • Bacterial formation occurs naturally. The thickness of biological sludge on the disks ranges from 1 to 2.5 mm, and accumulated sludge detaches from the disks through decomposition, maintaining the intended bacterial population.
  • Treated water exiting the Rotating Biological Contactor unit contains detached bacteria from the disk surfaces and some suspended solids. These must be removed via final sedimentation or filtration. After this process, treated water can be used for irrigation, car washing, cooling tower supply, or toilet flushing, following chlorination and filtration through sand and activated carbon systems.

 

Advantages of PlanetDISK®

Lowest Carbon Footprint Technology

Half-a-century proven German technology RBC has the lowest carbon footprint among all the technologies. This is vital for the 21st century!

Low Energy Demand

RBC System saves up to 90% in energy costs. Among all known Wastewater treatment technologies, RBC is the one that consumes the least amount of energy. Typical blower for an activated sludge treatment plant with a capacity of 250-350 people requires aproximately 80kW/day. Similar capacity, PlanetDISK® uses a 9kW/day for a small size electrical motor and a reduction gear to rotate the rotor at 3-4 rpm. That is all the energy required in the reactor part! Monthly energy costs per person per month at a typical PlanetDISK® plant is less than $0.14.

Renewable Energy Resources

Due to system’s low energy demand, it is easily operable with either solar or wind power.

No Smell, No Noise

No annoying smell or noise. The rotor rotates at 3-4 rpm and requires merely 0.37 kW power. It is quiet at 40 db! Each time the rotor surface is exposed to the atmosphere, plenty of oxygen diffuses to all the bacteria in the biofilm on the disks. There is no blower to blow the smell out of the system.

High Effluent Standards

Nitirification, denitrification and phosporus removal are all succesfully achieved by RBC systems.

Reliable Under Variable Loads

Consistent process results despite the organic load that may vary up or down by 250% for 2-3 days. Since the microorganisms in a fixed film System are attached to a media, they can not be washed out with increased flows as it does in most other systems. In places like villages or gray water projects, even though the bacteria levels are low and the waste water is diluted, the System still performs well and delivers required effluent standards.

Reuse of Waste Water

With tertiary treatment (sand+activated carbon filter or Ultrafiltration) and disinfection (UV or

chlorine) treated waste water can be used for irrigation, car wash, toilet flushing, cooling tower water and also at construction sites.

Easy Operation and Maintenance

Simple and economical to run. Does not require constant maintenance as required in other technologies. The biofilm layer forms on the surface of HDPP disks. The rotation of the rotor provides air (oxygen) to the biomass. There is no need to monitor parameters such as Dissolved Oxygen, MLSS, SVI.

Long Lasting

All the materials used to manufacturing PlanetDISK® units are corrosion proof. HDPP disks, GRP body tank, will last over 50 years. Rotor which is in Contact with water has SS and/or galvanized metal parts. 85 mm C1045-1050 solid shaft is epoxy paint protected.It is designed and built to last. Heavy duty bearings are pillow block type with selfaligning spherical roller bearings.

FAQ

What is a Rotating Biological Contactor (RBC)?

RBC is a biological wastewater treatment system where rotating discs support biofilm growth that removes organic matter from wastewater.

How does RBC system work?

RBC rotates slowly through the wastewater, allowing microorganisms to attach to the disc surface and grow with aerobic digestion. This repeated action treats wastewater.

What types of wastewater can be treated with RBC systems?

RBCs are suitable for domestic wastewater and various industrial effluents such as food, beverage, textile etc.

Which pollutants can be removed by RBCs?

Mainly Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Total Suspended Solids (TSS), and under proper conditions, nitrogen and phosphorus.

What are the advantages of RBC systems?

Low energy consumption, compact design, easy operation, minimal noise, no odor and low maintenance requirements.

Are RBC systems energy efficient?

Yes, RBCs consume significantly less energy compared to conventional activated sludge systems.

What flow rates can RBC systems handle?

They can treat flow rates from small-scale (10 m³/day) to mid-sized (up to 4,000 m³/day) with modular expansion.

Are RBC systems affected by seasonal temperature changes?

Temperature affects activity, but the biofilm structure allows microorganisms to adapt effectively to seasonal changes. There are multiple examples around World where RBC are used in very cold and very hot temperatures.

Can RBC systems achieve nitrification?

Yes, particularly in second or third stages, ammonia is oxidized to nitrate by nitrifying bacteria.

What materials are the discs made of?

Typically high-density polypropylene (PP) is ideal for biofilm growth. PlanetTEK uses virgin PP material in order to have well-balanced rotation. Virgin material usage helps for long life time of RBC.

What is the typical rotation speed of RBC discs?

Usually between 1 and 5 revolutions per minute (rpm), which ensures proper oxygenation and contact time. PlanetDISK® rotation speed is 3 rpm.

How is oxygen supplied in an RBC system?

Oxygen is passively transferred when the biofilm is exposed to air during disc rotation. Supplemental aeration may be used if needed. Supplemental aeration modification than can be applied for very hot temperatures.

How much sludge is generated in RBC systems?

Much less than activated sludge systems, and it is concentrated on the biofilm. This also reduces maintenance needs.

What are the maintenance requirements for RBCs?

Routine checks on the motor, bearings, and shaft are usually sufficient. Overall, maintenance is very
minimal. No monitoring for Dissolved Oxygen, SVI, sludge recirculation etc.

Are RBC systems prone to mechanical failure?

Due to their simple design and few moving parts, RBC systems have low failure rates.
Continuous electricity is a must for long time RBC life.

Can RBC units be installed underground?

Yes, they can be built in concrete tanks below ground or housed in containerized systems.

Are RBC systems modular?

Yes, the design allows for easy capacity expansion by adding new RBC modules. This spec
makes RBC special for new residential areas.

Can RBC systems operate with automation?

Absolutely. They can be integrated with timers, level sensors, flow meters, and SCADA systems
for full automation. PlanetTEK can provide complete automation with remote control.

How long does it take to start up an RBC system?

Typically, 1 week is enough for biofilm formation and the system to start effective treatment
without initial bacteria dosage. It depends on inlet BOD value, temperature etc.

What is the investment cost of an RBC system?

Lower than conventional systems due to simpler construction, smaller footprint, and reduced
power consumption. Low OPEX of RBC system makes big difference among all other
technologies.

What is the expected service life of an RBC system?

With proper operation and maintenance, service life can exceed 25–30 years. Most of the
components (PP discs and fiberglass body etc.) have 50 years lifetime.

Is chemical dosing necessary in RBC systems?

Not usually. However, chemicals may be added for specific needs like phosphorus removal.

Do RBC systems produce odor?

When properly designed and operated, they are odor-free. This is another advantage of RBC systems.

Are RBC systems resistant to hydraulic shock loads?

When supported by an equalization tank, RBCs can handle fluctuations in flow effectively. Thus,
RBC is very suitable for hotels, touristic areas, campuses etc.

Is RBC technology quiet?

Yes, compared to all other wastewater treatment technologhies, it is very silent, <50 db.

What is energy consumption of PlanetDISK® RBC?

Approximately 0,1 kWh/m3 energy consumption is needed. This makes RBC technology to use 7-8 times less energy.

Which industrial wastewater are suitable for RBC System?

Beverage, food production, textile, wineries, dairy etc. As a summary If the wastewater has
sensible BOD/COD (>0,35) ratio, RBC system can be applied with proper pretreatment.

What makes PlanetTEK’s RBC systems different?

PlanetTEK stands out with;

High-efficiency disc design with virgin material PP discs,

Low energy usage with only 0,37 kW motor-gearbox for 85 m3/day wastewater (depends on pollutants),

Most efficient and durable components are used,

Over 21 years of experience,

Serving on 5 continents,

Having fast and reliable technical support.

Let’s Build a Better Future Together

We’re here to answer your questions and explore how we can collaborate, wherever you are in the world.