Waste water supplies sustainable power and artificial fertilizer

Immediately after the summer, the Water Board Hunze en Aa’s will start a new purification process at the sewage treatment plant in Scheemda. In this process, products such as artificial fertilizer are recovered from waste water, whilst at the same time the process supplies sustainable power. This is a pilot project which will last for six months which is being conducted with DHV, Stowa, LeAF (TU Wageningen), HITC, NedMag, Water Board Noorderzijlvest and the Technical University of Delft.

Waste water partially consists of nitrogen and phosphorus. Recovering these substances from the waste water and binding these with magnesium results in struvite crystals. These crystals can be used as artificial fertilizer. However, Hunze en Aa’s is going a step further. Heating the struvite crystals from the first stage results in pure ammonia gas; this gas can then be used as power for a fuel cell that generates electricity and supplies heat. Extracting the nitrogen from the crystals leaves behind magnesium phosphate, which can almost directly be used as artificial fertilizer. For Hunze en Aa’s, the pilot is in line with the aim for increasingly sustainable business operations.