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Converting sewage to ultrapure water

Wastewater is treated so thoroughly in the Netherlands that it does not pollute our rivers and lakes. But in the town of Emmen the treatment process goes several steps further: after the existing wastewater treatment plant, the sewage water is upgraded to ultrapure water (UPW). The water becomes so pure that there is virtually ‘nothing’ else in it, not even the minerals normally found in drinking water. Sewage water provides the resource for the cleanest possible type of water.

The ultrapure water is supplied to Nederlandse Aardolie Maatschappij (NAM), part of Shell. NAM applies the UPW for steam generation. The steam is used for the extraction of oil at Schoonebeek in Drenthe province. The oil field there had been abandoned, but oil can once again be extracted at the site thanks to the new technique of steam injection, which makes the viscous oil more liquid. The ultra pure water prevents damage to pumps and turbines.

Innovative treatment

The owner of the UPW initiative and the producer of the water is NieuWater B.V., a joint venture of Water Supply Company Drenthe and the Velt & Vecht Water Board. Nieuwater opted for an innovative combination of treatment processes with minimum use of chemicals. Suspended particles are removed from the water by ultrafiltration membranes. Organic compounds are eliminated by means of biological active carbon filtration. Minerals and salts are extracted from the by double pass reverse osmosis treatment followed by electro-deionisation process.

Pure water plant: unique in the world

The plant’s total capacity is 10,000 cubic metres per day. The choice of feedwater, the scale of production and the innovative combination of treatment technology make this ultrapure water plant unique in the world. Witteveen+Bos provided the engineering for the project and was responsible for supervision and management during construction.