Paques PHOSPAQ - Innovative Process Technology for Phosphorus Recovery
PHOSPAQ™ is an innovative process designed by Paques for the cost-effective and sustainable recovery of phosphorus from industrial effluents and municipal sludge. The system removes biologically degradable chemical oxygen demand (COD), phosphate, and ammonium from wastewater. At its core is an aerated reactor that promotes optimal mixing of struvite particles and aeration. In this process, magnesium oxide facilitates the removal and precipitation of phosphate as struvite, providing a slow-release fertilizer solution or a feedstock for other applications like fire retardants. PHOSPAQ™ is integrated with separators to retain the struvite while discharging the treated effluent. By minimizing struvite scaling in pipes and equipment, it significantly reduces maintenance costs. With phosphorus being a finite resource crucial for many forms of life, PHOSPAQ™ plays a vital role in resource recovery and contributes to a more circular, sustainable economic model.
PHOSPAQ™ technology is a cost-effective and sustainable way to meet discharge requirements ánd recovery of resources from wastewater. LCA studies show that recovery from phosphate by formation of struvite has significant environmental benefits.
Advantages of PHOSPAQ™
PHOSPAQ™ combines the removal of COD with the removal and recovery of nutrients like ammonium and phosphate. PHOSPAQ™ removes up to 95% of the phosphate in wastewater. PHOSPAQ™ as been applied or treatment of municipal sidestream reject waters as well as in industrial wastewaters increased.
Feasability of PHOSPAQ™
PHOSPAQ™ is feasible from approximately:
- Load: > 100 kg P/d.
- > 50 mg/l PO4-P
- > 200 mg/l NH4-N
PHOSPAQ™ for removal and recovery phosphate
The PHOSPAQ™ process removes biologically degradable COD, phosphate (PO4 3-) and ammonium (NH4 +) from wastewater. PHOSPAQ™ is often implemented to increase the phosphorous removal to meet stringent discharge limits. It also prevents downstream struvite scaling of piping and equipment saving maintenance cost.
As phosphate is a finite resource essentially for all life, phosphorus recovery from wastewater has become paramount. PHOSPAQ™ allows facilities to harvest phosphate in the form of magnesium ammonium phosphate (struvite) which can be turned into a slow release fertilizer or used as feedstock for other products like fire retardants. PHOSPAQ™ is a cost-effective and environmentally friendly technology for phosphorus recovery.
The PHOSPAQ™ process takes place in an aerated reactor. Aeration provides optimal mixing of the struvite particles, simultaneously supplying oxygen for the biological conversion of COD. Stripping of carbon dioxide increases the pH and promoting struvite precipitation.
Magnesium oxide is added to remove phosphate that is recovered by precipitation as magnesium-ammonium-phosphate (struvite). The PHOSPAQ™ reactor is equipped with separators that retain the struvite and discharges the purified effluent.
The struvite is harvested from the bottom of the reactor and can, depending on the outlet requirements, be further processed, purified and dewatered.