Dutch mark European progress for Ostara wastewater phosphate recovery process

  • Features


This month has seen the official launch of the upgraded Amersfoort sewage treatment plant in the Netherlands which features the first Dutch installation of the phosphate recovery process of Vancouver-based Ostara Nutrient Recovery Technologies Inc.

The technology is at the heart of an ambitious project at the 300,000 population equivalent plant. The Vallei en Veluwe Regional Water Authority set out to transform the Amersfoort plant into one that produces energy and recovers raw materials and to achieve this in an economically viable way that can be replicated elsewhere in Europe.

Building on Dutch plans to implement an ‘Energy Factory’ concept at a number of sewage treatment plants around the country, the authority has taken this further with its ‘Omzet●Amersfoort’ project. ‘Omzet’ is the Dutch for revenue, linked to the project implementation site by the ‘●’ point character, hence the project’s web url is www.omzetpuntamersfoort.nl.

‘Amersfoort is a real-world example and it can be inspiring for other wastewater treatment plants.’

Cora Uijterlinde, STOWA

The Omzet project at Amersfoort combines sludge digestion and thermal hydrolysis to optimise energy production with introduction of biological phosphorus removal and use of Ostara’s Wasstrip phosphate stripping and Pearl phosphate recovery technologies. It is expected that the plant will produce a 30% electricity surplus of 2 million kWh/year and an estimated 900 tonnes of Ostara’s CrystalGreen high quality fertiliser.

The authority has partnered with the Dutch water authority research body STOWA and has received funding from the EU’s LIFE+ programme to support both implementation of the project and dissemination of its findings.

The contract for the project was awarded to SH+E, which now operates under the name of Eliquo Water and Energy as part of the Eliquo Water Group, owned by German investment company SKion. The Euro10 million contract involved supply of the company’s LysoTherm thermal hydrolysis process as well as the Ostara technologies. The overall expectations are to increase biogas production by 60%, recover up to 80% of phosphates, reduce sludge production by 17%, and reduce plant operational costs by 15%.

Cora Uijterlinde is the wastewater coordinator with STOWA. ‘We have an intensive research programme on resource recovery, and phosphate is one of the resources,’ she comments. ‘We now have the first Pearl reactor in the Netherlands – that hasn’t been done before. At other plants we recover struvite, but at this one with the Pearl system, you reach another quality of recovered phosphate. We want to monitor the Pearl reactor and also the other items of the new wastewater treatment plant,’

The official launch at Amersfoort was used as an opportunity for a seminar on phosphate recovery developments and to bring together a number of other LIFE projects, including those in which STOWA is participating.

‘I think we are now in a very interesting phase with resource recovery because we are exploring a lot of leads,’ says Uijterlinde. The coming period, in which approaches will be tried in different locations and results will show which options are of interest and which are less so ‘will be very exciting’, she adds. ‘Amersfoort is a real-world example and it can be inspiring for other wastewater treatment plants.’


  • Netherlands, resource recovery, phosphates, sewage treatment, Ostara