P-FIXATION AT RINGSEND WWTP

For the Phosphorus Fixation Project on Ringsend Wastewater Treatment plant, ​MEICA Consulting Engineers worked for the 3JV.  The 3JV is an engineering consultancy onsortium involving TJ O’Connor & Associates, a Dublin-based firm, JB Barry & Partners, part of Egis Group, a global engineering and operations firm, and Netherlands-based, global consulting and engineering firm Royal Haskoning DHV.

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This project forms an integral part of the upgraded facility allowing for the recovery of Phosphorus from wastewater. The process forms pearly coloured granules, which can be used as a slow-release agricultural fertiliser.

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The Ringsend WwTP Phosphorous Fixation & Recovery Project is the first of its kind in Ireland and is currently the largest in Europe by reactor volume. It involves the use of innovative technology to sustainably remove phosphorous from the wastewater being treated at Ringsend WwTP.

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The Phosphorus Fixation Facility in Ringsend is an great example of the circular economy in action. At full capacity, the Phosphorous-recovery facility in Ringsend will be capable of producing over 4,000 tonnes of fertiliser product per year, while removing 1.3 tonnes of phosphorous a day from the effluent discharged from Ringsend WWTP. The investment made by Uisce Eireann in this facility was €500.

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The process utilises a Phosphate Elimination and Recovery Lightweight (PEARL) reactor. It is designed to to recover phosphorus from pre- and post-digestion liquors, through the controlled precipitation of crystalline struvite. Within the Pearl system reactor, the growth of struvite (magnesium ammonium phosphate) is facilitated by the addition of magnesium in a controlled pH setting.  This allows nutrients to crystallize into eco-friendly fertilizer granules, which are harvested, dried and then distributed and sold.

 

The treated effluent is then discharged from the top of the reactor and returned to the plant with significantly reduced nutrient content.​​​