dws-waternet-fosvaatje-sh-e-770px-1SH+E Group started the construction of an Airprex unit at the waste water treatment plant Amsterdam-West, the Netherlands. The wwtp is operated by the city's water utility company Waternet who already digests its activated sludge for conversion to biogas. Early next year when the Airprex unit is ready, also valuable phosphate will be recovered from the sludge.

SH+E placed three recovery reactors that will produce 1,000 ton magnesium-ammonium-phosphate fertilizer (MAP) annually. This will be Europe's largest phosphate recovery at a municipal waste water treatment plant.

Double benefits
At the Amsterdam treatment works, currently phosphate is removed from the waste water by utilizing a biological P-removal process. By this process the phosphate is accumulating in the treatment work’s sludge’s and causing significant operational problems due to struvite blocking in pipelines, pumps and other treatment machinery. The new phosphate recovery unit will remove phosphate from the waste sludge streams and so eliminating the cost expensive blocking of various equipment.

Waternet is benefitting in two directions: elimination of cost expensive repair works as well the production of a valuable magnesium -ammonium -phosphate fertilizer (MAP).

dws-waternet-airprex-scheme-350pxThe AirPrex unit adds air (CO2 stripping) and magnesium chloride to the digested sludge. The formed struvite (MAP) is intermittently tapped from the conical reactor bottom.

Running out of phosphate rock
Most of the phosphorus used in fertilizer comes from phosphate rock, a finite resource formed over millions of years in the earth’s crust. Ninety percent of the world’s mined phosphate rock from e.g. Marocco and China, is used in agriculture and food production, mostly as fertilizer.

The expectation is that within 50 years the worlds natural resources of phosphor are exhausted.

This urges the necessity to re-use the valuable phosphorus as much as possible, taking the growing world population into account.

Currently changes in Dutch law and regulations are undertaken to allow recycled phosphate being used for the production of commercial fertilizers.

SH+E Group provided Waternet with the Best Economic Offer during a public tendering procedure. The Airprex-technology applied is licenced to the SH+E Group. Recently projects with the Airprex-technology were realized by SH+E in Germany and at the Dutch wastewater treatment plant Echten.

Recently the SH+E Group secured a new contract for the transformation of the Dutch Amersfoort treatment works into an energy and fertilizer producing wastewater treatment plant by the year 2015.
(read more on this website: Waterboard Vallei & Veluwe starts construction energy and nutrient facility at WWTP Amersfoort, the Netherlands, 8 September 2013)

This news item was originally published as a press release by SH+E Group.

More information
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