Everything that now disappears into our toilet bowl, we dilute so much with (drinking) water that it is no easy job for the sewage treatment plants (WWTPs) to extract valuable substances from it again. However, there is a lot of usable phosphate and nitrogen in domestic wastewater, which in turn can serve as fertiliser. Especially with the global scarcity of phosphorus expected by the middle of this century, phosphate reuse is becoming increasingly interesting. Phosphate - a key raw material in fertilisers - is now mainly derived from phosphate rock, which is mined in countries such as Morocco and China.
At the new phosphate plant, pure struvite crystals are produced. Micropollutants, such as metals and medicine residues, do not end up in the crystals, but attach to the sludge particles in the wastewater.
For CTC Tankbouw, the assignment consisted of designing, building, supplying and installing 3 pieces of patented Airprex® reactors and a complete stairwell with access landings at different levels. All devices were worked out in 3D by CTC Tankbouw and complex FEM (finite element) flow calculations were used to check and optimise the process in the reactors before starting construction. Because of the diameter of these reactors: Ø7850mm and Ø5500mm, they had to be transported by barge from Dilsen to Amsterdam. Once they arrived in Amsterdam, the timetable was tight because all the equipment had to be lifted over a rail track with overhead power within a time slot of 09.00 in the morning to 13.00 in the afternoon. So there was no room for delays or mistakes. Thanks to good planning and preparation by CTC Tank Construction, the 3 pieces of reactors and the staircase were brought in on 1 long day, lifted over the railway track and successfully attached to the foundation already in place. The attached timelapse gives an impression of the works.
