Aerobic biological treatment

Remove dissolved materials from wastewater

Aerobic treatment systems is based on a biological process operated and controlled under aerobic conditions (with aeration) that effectively treats COD, BOD and VSS into water, carbon dioxide and new biomass. Nijhuis aerobic treatment experts have vast experience and know-how to properly select, design, build and operate aerobic processes providing clients with the best treatment solution that is sustainable with the lowest cost of ownership.

Our BIOCTOR solutions come in a variety of proven options allowing Nijhuis to offer the best for a customer application. Whether you are interested in separation of your wastewater with membrane technology, flexible tank operations, need to reduce industrial wastewater pollutant load to very low effluent requirements, or treat industrial wastewater for water recycling, Nijhuis can incorporate the proper BIOCTOR technical approach, applied to a mixture of substances in the wastewater.

  • Aerobic-1
  • Aerobic-2
  • Aerobic-3

In general we can select one of the following solutions:

Sequence Batch Reactor, type BIOCTOR-SBR:

The Nijhuis BIOCTOR-SBR is an easy and flexible to operate single tank solution. All operations required in the process take place in one Sequence Batch Reactor tank. Consisting of a selector tank and aeration/ denitrification tank, the proven technology has a very small footprint in comparison with the continuous biological systems. The BIOCTOR-SBR can be executed with surface or bottom aeration.

Membrane Bioreactor, type BIOCTOR-MBR:

The Nijhuis BIOCTOR-MBR is a continuous sludge water separation by membranes, using flat plate or hollow fibre membrane modules and can be installed either in the aeration tank or in a separate membrane tank. Consisting of a selector tank and bottom aeration/denitrification tank, the solution can reach very low effluent discharge values and has no sludge return flow.

Moving Bed Bioreactor, type BIOCTOR-MBBR:

The Nijhuis BIOCTOR-MBBR is using carrier material to have a more effective growth of bacteria, whereby a compacter aeration reactor can be used. The solution is easy to maintain and has flexible upgrade possibilities. In case there is a strict suspended solids discharge limit, a flocculation-flotation system will be included to remove the solids.

Continuous reactor, type BIOCTOR-CONTINUOUS:

The Nijhuis BIOCTOR-CONTINUOUS is a 24/7 system where water flows by gravity through the required steps of treatment, with a clarifier or DAF for sludge and water separation. Compared to the traditional clarifier, using a DAF for sludge and water separation, makes the biological reactor more compact since a higher concentration of bacteria in the aeration tank can be maintained and a better effluent can be guaranteed.

Consisting of a selector tank and aeration/denitrification tank, the system is suitable for high flows. The BIOCTOR-CONTINUOUS can be executed with surface or bottom aeration.


We offer a wide range of surface and bottom aeration solutions for aerobic biological treatment, Nijhuis FLEX-AERATION, resulting in flexible and custom-made configurations which we design, realize and maintain. For surface aeration we offer Low Speed and High Speed aerators. For bottom aeration we offer Fine Bubble and Coarse Bubble aeration systems with tubes or discs.


  • Convenience and food processing
  • Fish, meat and poultry processing
  • Soft drink and beverage producers
  • Potato and crisps processing
  • Breweries, distilleries and wineries
  • Dairy processing
  • Edible oil processing

Customer Benefits

  1. Flexible selection of BIOCTOR solution, depending on your requirements.
  2. Flexible selection of surface or bottom aeration.
  3. High removal rates of BOD and VSS greatly reducing surcharge costs.
  4. Proven Nijhuis experience of applications in several industries.
  5. FLEX-AERATION solution, innovative fine-bubble aeration system to reduce installation costs for the piping grid.

Sub solutions