Terneuzen, The Netherlands


Municipal wastewater treatment


Nominal 400 m3/hour and Maximum 620 m3/hour




Municipal wastewater




Fresh water is scarce in the southwest of the Netherlands. This had lead Evides Industry Water to develop a unique water cycle project in close cooperation with the local waste water board Waterschap Scheldestromen. They installed a membrane bioreactor (MBR) from Pentair which treats municipal waste water to a very high discharge quality. The effluent is used to feed a demineralized water plant for the production of high value process water, which Evides supplies to a nearby facility of Dow Chemical.
The project was executed in two phases. In the first phase a part of the membrane filtration plant in the DeCo plant (for production of demineralized water and cooling water suppletion water) was refurbished and retrofitted in order to accommodate the new water source.

Additionally, the DeCo plant was connected to the municipal waste water treatment plant (WWTP) of the town of Terneuzen. Evides started to take effluent of the existing clarifiers of the municipal WWTP. 

In the second phase Evides produced approximately one million cubic meters of demin water using the municipal effluent. The production volume was limited due to capacity and operational limitations of the existing microfiltration (MF) pre-treatment step of the RO main desalination process step. 


Evides decided not to replace the mal-functioning MF plant but to build a MBR plant. The resulting effluent is of such superior quality that this source can be fed into the newly retrofitted RO plant, making the existing MF plant obsolete. The MBR plant offers additional treatment capacity of municipal wastewater for the expanding town of Terneuzen. To Dow Benelux the reuse of municipal waste water for its industrial processes represents a sustainable solution to its water demand.

The MBR process consists of vertically placed X-Flow UF housings. These are designed to prevent bio-fouling by not only allowing regular chemical enhanced backwashing and irregular CIP (chemical-in-place) treatment. Air purging from the lower bottom of the UF housings prevents clogging of the membranes and secures a regular return flow of sludge to the bio-reactor. The process is knows as Airlift MBR.

plant performance

The average daily production capacity if the MBR is 400 m3 per hour. In order to adapt to increased waste water flows during wet weather conditions this capacity can be temporarily expanded to a maximum of 620 m3 per hour.

water quality

 CZV  Kg/d
 1285  <60
 BZV  Kg/d
 395  <10
 Ptot  Kg/d
 13 <2 
 Ntot  Kg/d
 130 <10 
 Suspended matter  Kg/d  315 <1 


  • Expansion of the capacity of the local municipal WWTP
  • Improvement of the effluent quality of the municipal WWTP
  • No necessity of any investment in pre-treatment for the RO plant of Evides

  • The additional water source secures the long-term reliability of water supply to the chemical site of Dow
  • Full scale experience with reuse of municipal water for industrial purposes

scope of supply

- 420 Compact 33V membranes
- Airlift MBR
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