Proven treatment process - HolKof™ Bioreactor is a patented bioreactor like based on the mammoth pump and biofilm principle. designed for an effective aerobic and anaerobic decomposition of organic material (BOD), reduction of nitrogen compounds, oxidation of redox metals and precipitation of phosphate. The design allows the reactor can also be used to remove chlorate, for example. The bioreactor uses microorganisms. By adaptation and favorable operating conditions may be suitable microorganisms presented with the purpose of;

  • Reduce the amount of organic carbon, which prevents acid deficiency in receiving water areas.
  • Oxidize ammonium to nitrate and promote nitrate conversion to nitrogen gas.
  • Reduce substances that, discharged into water areas, contributes to eutrophication, such as nitrogen, phosphorus and organic material. As well as oxidizing redox metals and others reduced substances.

Customized solutions - HolKof™ - The bioreactor's design and capacity can Designed according to customer wishes and needs. In standard version has the bioreactor 6m3 biofilm carrier that gives over 1800m2 active area, in developed biofilm. In connection with an installation of HolKof™ Bioreactor, there are also the possibility of signing a service agreement. An easy way to ensure function and energy efficiency. Washing, review and adjustment is included in the basic agreement. Together we adapt scope according to customer requirements and needs.

HolKof™ Bioreactor is an energy efficient cleaning as well that the flow is checked and provides a controlled one circulation. The solution is mobile, energy efficient and compact. It can be customized according to specific environments and its cost-effectiveness over, for example an SBR facility makes it economically good alternative.

The system was developed primarily for the reduction of ammonium, which is a major problem for landfill owners and for eutrophication in nature. Ammonium is oxidized on the surface of the biofilm to nitrate that is further into the biofilm used as the electron acceptor and reduced to nitrogen. The BOD is consumed in denitrification and also at the surface of the biofilm. The phosphorus and redox metals are oxidized and settled in the sediment.

Airturbo™ RV2 MGE, offers:
Low operating costs - Thanks to the design of the impellor and the IE5 classified MGE motor. The IE5 features of the MGE motor the energy demand is reduced by up to 50%. At normal operation the energy consumption is approx. 2,5-3.0kW.
More efficient aeration - For each operating hour 52m³ of pure atmospheric air is supplied and distributed with great efficiency beneath the water surface in a large volume of water. The capacity of oxygen addition is more than 90kg O2 per day based on measurements in test tank (SOTR).
Efficient Nitrate reduction - Ammonium nitrate reduction up to 80-90%.
Low maintenance costs - Thanks to the IE5 classified MGE motors unique features, such as Soft start and Self-regulating speed in relation to load, in combination with the Airturbo™ RV2 robust construction minimizes maintenance cost.
Remote Management via IoT - As an option we offer the opportunity to monitor and remote control the aerator via IoT. Operating changes and energy consumption can be tracked and documented for optimal operation.

Clear results
HolKof™ Bioreactor contributes to a powerful improvement in the purification efficiency of ammonium nitrogen. Even under less favorable conditions the bioreactor demonstrates these good results.


  • Leachate
  • Sewage
  • Industry wastewater
  • Stormwater
  • Fish farms
  • Restoration of eutrophic streams, lakes and ponds
Emilia Öberg, Karlstad University 2017
Ammonium nitrogen reduction at leachate treatment with mobile bioreactor
- at different temperatures and phosphorus supplements

The need for energy efficient and well-functioning water treatment systems is high, and grows as the growing population increases. Leachate is formed as water flows through landfilled waste. The problem of leachate treatment is that the reactors are located outdoors, which causes low temperatures during the winter months. As the leachate treatment is mainly carried out with biological purification techniques, the low temperatures cause a decrease in bacterial activity, which reduces the purification efficiency. Another problem that often arises in this type of water treatment is that the contaminated water consists of high nitrogen levels, while phosphorus levels are low. This gives an imbalance in the metabolism of the bacteria and can lead to limitations in purification efficiency.
In this work, a newly developed bioreactor, which is tested at Djupdalen's waste facility, has been investigated. The bioreactor was put into operation in autumn 2015 and from April to December 2016. Measurement data from Djupdalen based on monthly water samples and chemical analyzes for 2014-2016 have been studied to find out the bioreactor's contribution to the purification efficiency of ammonium nitrogen.
Water sampling was carried out in May 2017, where purification efficiency and active biofilm surface were calculated during the operation start of the bioreactor. Finally, experiments were performed where biofilms from Djupdalen were tested at 17-18 as well as 12-15 ° C with different levels of phosphorus supplementation, to investigate whether purification efficiency could be improved if phosphorus levels were increased.
The results indicate that the bioreactor contributes to a significant improvement in the purification efficiency of the aeration reactor, but there is still an improvement potential. Several of the environmental factors in the aeration reactor cause less favorable conditions for bacterial growth, such as temperatures below 15 ˚C, severe phosphorus deficiency in the incoming leachate and slightly for basic pH values. Through water sampling and the accompanying chemical analysis it was found that temperatures above 15 ˚C in the leachate favor a faster development of the biofilm. Finally, laboratory experiments showed that phosphorus additions at temperatures of 12-15 ° C resulted in increased purification efficiency, while the result was unchanged for temperatures of 17-18 ° C at a water residence time at 24 hours. However, at a lower water residence time of 16 hours, the phosphorous supplement gave an effect for both temperatures. This indicates that a phosphorus supplement during the autumn of the aeration reactor, when the temperatures in the leachate go below 15 ˚C, should allow the bioreactor to improve its purification efficiency despite the sinking water temperature.