The biological phosphate elimination removes phosphates without the use of chemical precipitants.
This environmentally friendly and cost-saving process also has disadvantages:
This is how AirPrex® works:
The AirPrex® process improves biological phosphate elimination. The digested sludge is fed into the AirPrex® reactor where it is subjected to CO2 stripping through aeration. The CO2 increases the pH of the sludge significantly. At the same time, the addition of magnesium salts leads to the formation and precipitation of magnesium-ammonium-phosphate (MAP). The crystals integrate homogeneously into the sludge matrix. The recovered MAP can then be used as fertilizer.
AirPrex® can significantly increase the profitability of a sewage treatment plant. The unique solution for the struvite problem ensures smooth processes and best results in phosphate elimination:
With AirPrex® Micro there is no struvite recovery, microcrystals remain in sludge for targeting ≥ 80% P recovery from ash.
AirPrex® Macro, besides struvite harvesting, includes further P release into the second mixing tank where further struvite growth and sedimentation occurs, enabling microcrystals recovery.
The same benefits as AirPrex® Micro and additionally: