Aqua Strategy review: Process progress with sewage phosphate recovery

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Momentum is growing around the recovery of phosphates from municipal wastewater. In this and the following article, Keith Hayward reviews some of the notable project and process developments in Europe and North America this year with commercially-available and emerging technologies.

Phosphate fertiliser © shutterstock / Fablok
Phosphate fertiliser. Fertilisers are one of the main product options for recycled sewage phosphate. © shutterstock / Fablok

Nutrients represent one of the main pollutants of the aquatic environment, especially due to fertiliser washed from agricultural land or inputs from livestock manure or human sewage. At the same time, phosphates in particular are increasingly seen as a concern given that the rising global population depends on a finite supply of this essential resource. It is against this backdrop that initiatives are progressing on both sides of the Atlantic in order to promote nutrient recycling.

In the US, the Environmental Protection Agency is leading the Nutrient Recycling Challenge, aimed at promoting nutrient recycling using livestock manure. Earlier this year the EPA announced the first phase winners. A total of 34 entries were then selected to continue to the second phase of the challenge, running from October to March 2017. In this non-competitive part of the challenge, the entrants are being called on to develop technology designs based on their initial concept proposals. The third phase anticipated for next year will see prototyping and proof of concept, with a fourth phase involving demonstration units on farms.

The initiative therefore recognises that technology has a part to play in developing alternative approaches, and the first phase winners included the AnSBEAR process, which features two-step electrocoagulation of anaerobic digestion supernatant, the AirPrex process, and systems from Paulee Cleantech Ltd and Bravespec Systems.

In Europe, the interest in nutrient recycling will gain in the long term from the wider commitment to building a circular economy. Last December, the European Commission launched a new circular economy initiative. Europe’s long term goal is to achieve a vision by 2050 of ‘living well within the limits of the planet’.

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Keywords: 

  • resource recovery, phosphates, nutrients, Ostara, NuReSys, Colsen, Veolia, Outotec, Paques, Ovivo, Black & Veatch