urine is helping solve the fertilizer crisis

I never imagined that one day I would find myself in the position of calculating how much human urine Spain produces each year, but here we are: adding permanent residents and international tourists, the country produces 23,948 million liters of urine per year.

23,000 million that we are literally flushing down the toilet and that, in short, could help us solve the enormous problem that is approaching us with the fertilizer crisis.

Use urine as fertilizer? It’s not a new idea. In fact, it has been around for more than fifteen years and there are already commercial fertilizers on the market (the Swiss Aurin, for example) and others that are under development (one in Spain by the ICTA-UAB).

In places as diverse as the United States, France or the International Space Station, the use of urine is the order of the day. For years the Rich Earth Institute Vermont (USA) has a program dedicated to examining the safety and efficiency of using urine for this purpose. As they themselves explained on the BBCthe idea of ​​recycling urine responds to two basic reasons: the first is “the fertilizers it produces, which are valuable for agriculture”, the second is “the pollution it avoids”.

Resolved. As if that were not enough, as our DAP colleagues explainthe University of Surrey has just solved one of the key processing problems: clouding of membranes in the concentration process.

And then? If we have been working for 15 years, why do we still depend on the Gulf? Because the barrier is not scientific, the barrier is infrastructure and regulation. Let’s think about it for a moment: yes, Spain produces almost 24,000 million liters of urine, but how the hell are we going to collect it?

We would need an entire circuit of toilets with urine separation, a channeling, collection and processing system on a national scale. Plus, if we had all that, there would still be a ton of regulatory issues and associated risks (like pharmaceutical waste).

The thing is moving. That is true: the rising price of Gulf urea makes all these alternatives more attractive. And it does it automatically. In that sense, the 473 liters of urine produced by each adult can be a small ‘gold mine’.

The issue, as I say, is that it is not simple: studies indicate that in the sewer urine is diluted up to 100 timesso it must be separated at source and collected with separate circuit toilets (something that, well, right now is anecdotal in urban environments).

But it starts somewhere. Because, as said Siddharth Gadkari, lead author of the study published in the Journal of Environmental Chemical Engineering, human urine hides a kind of paradox: “although it contains the essential nutrients we need for agriculture, we currently treat it as waste.”

With a little luck, these connection tests will move legislation and in a few years we will begin to see how that begins to change.

Image | Philippe Murray Pietsch

In Xataka | Going to the bathroom is a waste: urine is the real liquid gold and is full of valuable things