Greenhouse Canada

Canada’s first commercial nutrient recovery facility

August 16, 2013  By Dave Harrison

Aug. 16, 2013, Saskatoon — Canada’s first commercial nutrient recovery
facility has been installed at the city’s Wastewater Treatment Plant.

Aug. 16, 2013, Saskatoon — Canada’s first commercial nutrient recovery facility has been installed at the city’s Wastewater Treatment Plant.

The project is the first commercial plant of its kind in Canada to use the Pearl® nutrient recovery process of Ostara Nutrient Recovery Technologies Inc. to recover phosphorus and nitrogen from the facility’s wastewater stream and transform them into Crystal Green®, a slow-release and environmentally responsible enhanced efficiency fertilizer.


“The example of responsible stewardship of our resources begins at home,” said Saskatoon Mayor Donald Atchison.

“With the installation of Ostara’s technology at the Wastewater Treatment Plant, we are proactively and cost-effectively, tackling the growing issue of nutrient overload in our regional waterways. And that’s good for taxpayers and good for the environment.”


By removing potentially polluting nutrients from the treatment facility’s wastewater stream, Ostara’s technology helps the city meet nutrient discharge limits and overcome operational issues caused by the unintentional build-up of struvite scale in plant equipment.

Struvite is a concrete-like mineral deposit that chokes process equipment, increases operating and maintenance costs, and undermines plant reliability. The formation of struvite is a common challenge in plants that practice biological nutrient removal and anaerobic digestion.

In Saskatoon, the sludge is handled at a bio-solid facility that is 12 kilometres from the treatment plant where it is stored.

The struvite problems are exacerbated as the sludge must travel this distance through pipes from the treatment plant to this facility, and then pump decant water back to the treatment plant.

Keeping the pipes clear of struvite is a significant operational challenge, especially in the winter. Chemical additives can sometimes be used to mitigate struvite problems, however they are costly and result in a higher volume of sludge waste requiring disposal.
The Ostara system will help the City overcome these challenges by recovering 75 per cent of the phosphorus and 10 per cent of the nitrogen from the wastewater stream before they accumulate in the equipment.

Using Ostara’s Pearl 2000 system, Saskatoon’s new nutrient recovery facility has an annual production capacity of 730 metric tons of Crystal Green fertilizer using the nutrients recovered by the process, for which the City receives revenue.

This is also Ostara’s first commercial implementation of WASSTRIP®, a process that increases the amount of phosphorus available for recovery by up to 40 per cent, enhancing the efficacy of the Pearl process and controlling struvite scale formations throughout the sludge treatment stream.

The nutrient recovery system installed at the plant will result in significant annual cost savings and provide a revenue stream earned from the fertilizer produced. The system installed at the Saskatoon treatment plant cost $4.7 million.

Ostara’s nutrient recovery process helps to address one of the planet’s most critical environmental challenges: the proliferation of algae blooms that impair waterways and destroy aquatic life. Ostara’s technology recovers excess nutrients before they have an opportunity to accumulate and transforms them into an environmentally responsible, slow-release fertilizer called Crystal Green.


A blend of phosphorus, nitrogen and magnesium, Crystal Green is the first nutrient technology to offer a plant-activated, slow-release fertilizer sustainably made from renewable sources.

Crystal Green responds to plant demand, releasing nutrients only when the roots need them, resulting in greater fertilizer efficiency, lower application rates, and reduced nutrient loss through leaching and runoff.

It is used by growers in the agriculture, turf and ornamental sectors throughout North America and in Europe.

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