Ostara's Crystal Green fertiliser is eco-friendly and sustainable

Nutrient-recovery reactor creates sustainable fertiliser

A new £2m sewage treatment facility providing a sustainable source of environmentally-friendly fertiliser has been unveiled.

Thames Water has created the nutrient-recovery reactor, the first of its kind in Europe, to produce sanitised phosphorous-based fertiliser from the "unique" waste water coming out of the industrialised area surrounding Slough in Berkshire.

The company says the high-strength organic waste coming from the Slough Trading Estate is rich in the nutrients ammonia and phosphorous, which causes struvite – a rock-like scale on pipes at the sewage works costing Thames Water £200,000 a year to clean.

The facility, built by Vancouver-based Ostara Nutrient Recovery, makes the phosphorous form into struvite in a controlled setting, before turning it into crystalline fertiliser pellets, which the company markets under the brand name Crystal Green, which it says is cleaner than any similar product on the market with lower heavy metal content.

Piers Clark, commercial director for Thames Water, said: “This is a classic win:win. We are producing eco-friendly steroids for plants, while also tackling the costly problem of struvite fouling up pipes at our works.

“The cash and carbon cost of digging phosphate out of the ground in a far-flung foreign clime then shipping it back to Britain makes no sense when compared to the local, sustainable process of our reactor in Slough. As we gain experience with this new technology, we intend to evaluate its suitability for installation at other Thames Water plants in the UK.”

He added: "Slough has taken some stick over the years, from the likes of poet John Betjeman and Ricky Gervais, but this scheme is rebranding it as an eco-warrior at the forefront of the global effort to save the planet.”

Europe's first nutrient-recovery reactor made by Ostara According to the company the price of phosphorous, the key ingredient in fertiliser, had increased by 500 per cent since 2007 as the availability of mined phosphate rock dwindles from non-renewable reserve, with experts predicting complete depletion of reserves within 100 years.

Peter Melchett, policy director at the Soil Association, said: "With the world's affordable mineable reserves of phosphorous set to start running out in the next 20 to 30 years, this new technology could offer a solution to securing global food supplies over the coming decades.

"Without fertilisation from phosphorous, wheat crop yields will fall by more than half. Meanwhile, as the planet's population is predicted to hit nine billion by 2050, demand for food will increase. Sustainable alternative sources of phosphorous, like this reactor at Slough sewage works, are vital if we are to keep pace with this demand."

The UK uses 138,000 tonnes a year of phosphate fertiliser, all of which is imported from abroad, but the reactor will produce 150 tonnes a year.

Phillip Abrary, president and chief executive of Ostara, said: "This new facility is a model for sustainable innovation in the UK and indeed across Europe.

"Removing nutrients from where they shouldn't be, in our waterways, and using them to create a new generation of enhanced-efficiency fertiliser is the smart thing to do economically and the right thing to do environmentally."

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