Responsible partner: Aquafin NV

Type of feedstock: Real municipal wastewater/urban wastewater

Nutrients recovered: 

  • Mainly nitrogen: Ammonium sulphate ((NH4)2SO4); Ammonium nitrate (NH4NO3)
  • Eventually phosphorus and potassium

Process technologies: 

  • HRAS (high-rate activated sludge)
  • Adsorption/ion-exchange



A novel 2-stage process that combines (1) high-rate activated sludge (HRAS) and (2) adsorption/ion-exchange will be set up.

The first stage (HRAS) will mainly focus on the removal of organic matter. Aquafin foresees a sequencing batch reactor (SBR) to explore the potential of HRAS treating urban wastewater. The pilot will be able to deal with a discontinuous influent flow of 1300 L/day.

During the second stage (adsorption/ion-exchange) we aim to recover at least 50% of the total nitrogen content from the influent wastewater, in the form of ammonium sulphate (from regeneration of the adsorbent) or as saturated adsorbent. On lab-scale, the type of adsorbent and dimensioning of the pilot are still under investigation. Bed volumes per hour (BV/h) are estimated between 8 and 40.