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Pearl®

High phosphate recovery

By using this unique patented technology based on fluidized bed reactor is used to produce the high quality Crystal Green® ready-to-use fertilizer out of the liquor stream of sludge dewatering facilities. ELIQUO is currently undertaking the design and realization of the first Pearl® plant on the mainland Europe at the WWTP of Amersfoort, the Netherlands.

Many wastewater treatment plants concentrate large quantities of nitrogen and phosphorus in their sludge dewatering streams. The dissolved nutrients promote the formation of obstructive struvite scale in piping, pumps and valves resulting in severe impacts to plant reliability, efficiency and operating and maintenance costs.

Ostara’s Pearl® Process resolves struvite issues and provides a comprehensive approach to nutrient management. The technology is based on controlled chemical precipitation in a fluidized bed reactor that recovers struvite in the form of highly pure crystalline pellets or “prills.” Nutrient-rich feed streams are mixed with magnesium chloride and, if necessary, sodium hydroxide and then fed into the Pearl reactor where minute particles or struvite “seeds” begin to form. Like a pearl, these seeds grow in diameter until they reach the desired size – 1.0 mm to 3.5 mm – which is precisely controlled by varying key parameters. In a municipal wastewater treatment plant, up to 90 per cent of the phosphorus and 40 per cent of the ammonia load is removed from sludge dewatering liquid using this process and the resulting product is marketed as a commercial fertilizer called Crystal Green®.

Crystal Green®

Made by Ostara Nutrient Recovery Technologies, Ostara's proprietary Pearl® technology sustainably transforms phosphorus and nitrogen recovered from nutrient-rich water streams, plus magnesium, into a high-value, eco-friendly fertilizer that enhances nutrient efficiency, while significantly reducing the risk of leaching and runoff.

  • Season-long nutrient release of 160-200 days;
  • Promotes healthy root development;
  • Phosphorus and magnesium work together for more vibrant growth;
  • Significantly reduces risk of leaching and runoff;
  • Minimizes nutrient loss;
  • Suitable for turf, nursery, agriculture and specialty agriculture;
  • Tested at leading universities and in field trials;
  • 99.9% pure, dust free compound;
  • Uncoated, slow-release nitrogen, phosphorus and magnesium;
  • Available in a variety of SGN's including 100, 150, 240;
  • Recognized by Audubon International.

In close cooperation with Ostara we offer our clients attractive and guaranteed long-term off-take agreements, providing a guaranteed fundament for the economic feasibility of the involved investments.