The world's largest plant for purification of Produced Water using MBBR technology is to be built in Fredericia

The consortium SUEZ - MTH wins the contracts for both construction and operation of a treatment plant for Danish Oil Pipe A / S (DOP), which will be the world's largest plant based on MBBR technology for the treatment of Produced Water from crude oil production.

Danish Oil Pipe A / S (part of ØRSTED), which operates the crude oil transport system from the North Sea to the mainland, has decided to build a permanent treatment plant for the saline Produced Water from oil production in the North Sea. This project is the largest treatment plant in the oil and gas industry using MBBR technology. The plant replaces the disposal of the water to other plants and will result in a local purification of the water. This will ensure a significant environmental improvement overall for DOP.

To optimize its investment and operations, DOP awarded two contracts in parallel:

  • “Design Build” contract (construction)
  • Operation and maintenance contract that can be extended until 2050.
The contracts were awarded on 19 April and were signed on 4 June 2021 by DOP and the consortium SUEZ - MTH.


Per Krøyer Kristensen, CEO of SUEZ in Denmark, states that "for the entire SUEZ international, the project is the largest global reference within this type of purification - and it also shows that we have a convincing technical and process solution that has won the competition".

The consortium has developed a multi-barrier solution that makes it possible to treat very varying quality of Produced Water. SUEZ - MTH's solution has been developed with a focus on flexibility and robustness. This completely covered system is designed to be safe, easy to operate and minimize operating costs.

Due to the highly variable quality of the incoming water, the system is designed with several different adjustable solutions that the operator can adjust in real time according to the variations in the composition of the inlet water. This highly adjustable construction model offers a very reliable solution where the water is purified environmentally optimally, but also optimizes operating costs.

“We are now starting up the complex MBBR treatment plant in Fredericia, where we look forward to a close collaboration with SUEZ in Denmark and Danish Oil Pipe. The EPC contract has been tendered in accordance with Yellow FIDIC, with which we also have good experience from the past. We have previously collaborated with SUEZ in both Sri Lanka and Bangladesh, and most recently at the NAU treatment plant in Aalborg, and our knowledge from here will definitely benefit the project in Fredericia ", says Eva Kjeldahl-Braad, section director at MT Højgaard Denmark.

The project was awarded following a very extensive and particularly stringent procedure.

Throughout the process, SUEZ-MT Højgaard has focused on thoroughly discussing and improving every aspect of the plant to ensure reliability and flexibility. In addition, the focus is on environmental optimization, SUEZ WATER A/S Page 2 / 2 Sletvej 2E, 8310 Tranbjerg J, Denmark ̶ CVR: 1445 1234 service, quality assurance, health and safety, planning and optimization of investment and operating costs. Teamwork, motivation and mobilization of several experts on the part of SUEZ-MT Højgaard have been the most important success factors.

"All employees are very positive about being named the winner and we will make an effort together with MT Højgaard Denmark to deliver the best result in the execution of the plant - and the subsequent operation", says Per Krøyer Kristensen.

About MBBR

MBBR (Moving Bed Biofilm Reactor) is a biological treatment process of wastewater. The system consists of an aeration tank with special plastic carriers that provides a surface where a biofilm can grow. The carriers are mixed in the tank by the aeration system and will thus have good contact between the substrate in the wastewater and the biomass on the carriers.

Key Facts

  • Customer name: Danish Oil Pipe A / S, subsidiary of ØRSTED
  • Location: Fredericia, Denmark
  • Project name: Treatment plant for saline Produced Water and Oil and gas platform
  • Contract type: DB (Design Build) and operation and maintenance contract
Visualization of the facility ©SUEZ
Visualization of the facility ©SUEZ