July 10, 2014 by John Crapper
Not long ago Dutch officials lined up some not-so-private urinals in an Amsterdam park and asked local men to come pee. But instead of having the pee flush down the drain and piss it away the local water district turned it into fertilizer.
Phosphorus extracted from the temporary park urinals will go to a green roof in the city. And today, the water utility will launch a new recovery plant designed to mine the phosphorus out of all of the wastewater in the region. Amsterdam’s pee alone can fertilize 10,000 football fields’ worth of plants, according to officials.
Who cares about phosphorus? For starters, every living thing on Earth—including humans—since all the crops we eat depend on it to produce healthy cells. Until the mid-20th century, farmers maintained phosphorus levels in soil by composting plant waste or spreading phosphorus-rich manure. Then new mining and refining techniques gave rise to the modern phosphorus fertilizer industry—and farmers, particularly in the rich temperate zones of Europe and North America, quickly became hooked on quick, cheap, and easy phosphorus. Now the rest of the world is scrambling to catch up, and annual phosphorus demand is rising nearly twice as fast as the population.
Our addiction to cheap P (as it’s known in the periodic table) is risky for two reasons. The first, better-known one is that not all the phosphorus that farmers put on their land is absorbed by crops. A lot leaches into water, ending up in lakes and rivers, where it causes algal blooms—which, as they decompose and suck up oxygen, create dead zones.
But the scarier reason is that, like any mined material, phosphate rock is a finite resource, and there’s fierce debate about just how long our supply can last. “Peak phosphorus” doesn’t get a lot of buzz, but it should. In a recent essay in Nature, Grantham, who also runs an environmental foundation, put the case bluntly: Our P use “must be drastically reduced in the next 20-40 years or we will begin to starve.”
This idea all started because phosphorus in the urine was causing problems by forming crystals in the sewage pipes and clogging them.
“We thought, if we have to remove it, why not do it in a proper way,” said Peer Roojimans, who serves on the board of the water authority. “Phosphorus is needed for survival for everything in life, but it’s a limited product, and the mines are exhausted. Since everyone takes it with us every day–and supplies it to our sewage treatment plant when we go to the toilet–we wanted to develop a device that could reuse it.”
So the Dutch are developing a sewage treatment facility that will separate the nitrogen and phosphorus from the urine and transform it into a slow release fertilizer called struvite.
Lest it seem that poo has been left out of the plan, Roojimans points out that the entire wastewater treatment plant for the Amsterdam area–which serves a million people–runs entirely on electricity that is produced from solid waste.
Now Amsterdam residents can be proud to know they’re cleaning up their environment, recycling and helping to alleviate a growing scarcity of phosphorus every time they flush.
As Poop John the First of the Church of the Holy Shitters I declare this a first class example of ass-forward thinking which puts waste-end considerations up front and center.