Windmill 2014 even "greener": Phosphorus recovery from wastewater

Windmill 2014 even "greener": Phosphorus recovery from wastewater

Written by Enna Klaversma and Aljaž Gaberšek.

So you know all about phosphorous and the world food supply, etc. OK, but did you know we're making Windmill even more sustainable this year? By pooping and urinating (in the designated areas, of course) at Windmill Windup, you can do your part in the circle ... the Circle of Life!

Phosphorus (P) is an essential element for all growth on Earth, but its sources are becoming scarcer. It comes mainly from mines in China and Morocco, and some studies estimate these mines will be empty within 50 years. Enter: P recovery systems.

Usually, phosphorus contained in our faeces and urine is flushed away from the toilets to the wastewater treatment plants (WWTP). At these, it is concentrated in wastewater sludge, which is then incinerated. After incineration, the phosphorus ends up in the ashes, and after becomes embedded in concrete or bitumen. So, the phosphorus is "gone"! 

The ‘FosVaatje’ is a new installation at the WWTP Amsterdam, built to recover phosphorus from wastewater sludge. It is done so in the form of ‘struvite’ (magnesium ammonium phosphate), which can be then directly used as fertilizer. With urine, recovery from 'pure form' makes even more sense, as 50% of all P at the WWTP comes from pee (geddit?). Also of note: Amsterdam is bound to start with P recovery from pure urine in August this year.

So, there you have it: some of the feces and urine we produce during Windmill will be used in phosphorus recovery! We’ll demonstrate how it works with urine, with the now famous ‘peeing cross’ (see video).

For more information, you can watch the phosphorus issue explained in this video, or add to your existing knowledge of the thing that makes the yellow snow, by checking how fertiliser is made from your pee, here.