Associated Case Studies: Coalburn Wastewater Extension

Napier-Reid’s RBC with Bio-Rotor™ Technology

Bio-Rotor™ is an extremely efficient secondary biological wastewater treatment system. It utilizes aerobic fixed film technology to reduce organic matter (BOD5), total suspended solids (TSS), ammonia and phosphorous from domestic and industrial wastewater, achieving a high quality final effluent that is safe for discharge.


Features and Benefits

  • Tested Technology. Bio-Rotor™ is capable of treating a wide range of flows without compromising effluent quality and able to handle overloading for short periods of time.
  • Easy and Immediate Start-up. The system is designed to be a complete wastewater treatment plant. Because it is preassembled, the system’s start-up requires minimal technical experience and wastewater treatment can begin immediately.
  • Low Operating Cost. Our RBC system has very low energy consumption and little skill is required in plant operation.
  • Low Maintenance Cost. Stable operation without frequent supervision. It only requires drive and bearings lubrication and bi-annual sludge removal. Continual monitoring of the wastewater quality is not necessary.
  • Inoffensive and Unobtrusive. Because Napier-Reid’s Bio-Rotor™ is virtually silent and odour free, it can be placed near public places. And when supplied with the optional FRP cover, it gives the system a low profile that is aesthetically pleasing in any environment.
  • Environmentally Friendly. Bio-Rotor™ is energy efficient and does not use toxic chemicals that can harm the environment. The effluent produced is clean and safe enough to discharge directly to surface watercourses or subsurface tile beds.
  • Flexibility and Sustainability. Additional systems can be installed in parallel to increase the total capacity as population grows.


Treatment Process

The process consists of corrugated plastic media arranged around a horizontal shaft, placed in a tank. The media is slowly rotated. 40% of the media surface area is submerged in wastewater. Organisms in the wastewater attach and multiply on the rotating media until they form a thin layer of biomass. This fixed film growth presents a large, active population for the biological degradation of organic pollutants.

Whilst rotating, the media transports biomass and wastewater into the air and oxygen is absorbed. The wastewater contains dissolved oxygen and organic materials which are then diffused into the biomass and metabolized. Continuous growth of the biomass is allowed via the corrugated media which allows wastewater and air throughout the surface area.

Depending on temperature, organic loading, and other variables, the biomass thickness can vary. As the media rotates, excess biomass shears off at a steady rate, allowing for a stable process with minimal operator input. The sheared off biomass flows through the RBC system for removal in a final clarifier.



When the proper influent environmental conditions exist within the wastewater such as alkalinity, temperature, low BOD, and ph, the reduction of ammonia nitrogen can be easily achieved. Ammonia nitrogen values can be reduced to values less than 1.0 mg/l.


Package Wastewater Treatment Plant

Napier-Reid’s Package Bio-Rotor™ RBC plant

Napier-Reid’s Package Bio-Rotor™ RBC plant

Napier-Reid’s Package Bio-Rotor™ RBC plants combine separate processes (as required): biocontact, secondary clarification, tertiary filtration, and disinfection – into one complete unit, and are generally provided for small and medium population ranges.