Why Turn Your Urine into Fertilizer?
|Watch a video of the artists explaining the overall concept to workshop participants.
Normally, we'd flush our pee down the toilet.
It would go through a bunch of pipes and eventually emerge into a sensitive aquatic ecosystem.
Unfortunately, sewage treatment plants don't really treat pee and it's the really potent stuff.
Our pee carries most of the excess nutrients our body can't process.
Out in the ocean, concentrated nutrients overfeed algae and suffocate vast tracts of ocean life.
Our pee also carries our unmetabolized medicines (up to 80% of intake goes right back out).
These meds not only dose unsuspecting sea creatures,
they've been showing up in our collective drinking water supply.
Guess what. We've been drinking each others' pee. Evidently, it doesn't go away when we flush.
Scientists are working on mass solutions to these problems of overgrowth of algae and pharmaceuticals in the water supply. These solutions are interesting, but they involve ripping up the entire infrastructure of our cities.
We looked at the chemistry behind what the scientists were doing and saw that there's actually a way we could do it ourselves. We figured out how can we take this out of the big R&D labs and make something that we can do at home. The result of this workis the Urine to Fertilizer Kit.
The reaction that is done with the Urine to Fertilizer Kit turns your pee's nutrients into a houseplant-ready fertilizer and may keep up to 98% of the meds in your pee out of the drinking water supply.
From the scientists at EAWAG Aquatic Research:
Although urine makes up only 1% of the total volume of wastewater, it accounts for 50–80% of the nutrient content. Nutrients have to be removed by resource-intensive processes at wastewater treatment plants. In the absence of these processes, nutrient discharges pose a risk of eutrophication – threatening in particular coastal waters and fish stocks. Many problematic substances, such as residues of medicines or endocrine disrupters, also enter wastewater via urine and may subsequently be released into the environment. The Swiss Federal Institute of Aquatic Science and Technology (Eawag) has now shown that separate collection and treatment of urine could make significant contributions to water pollution control and nutrient recycling worldwide . . .
Novaquatis tested various methods of processing urine. Ideally, treatment should permit recycling of nutrients as fertilizers and, at the same time, removal of problematic micropollutants. For example, 98% of the phosphorus in urine can be recovered by precipitation with magnesium. The product – struvite – is an attractive fertilizer, free of pharmaceuticals and hormones. In Switzerland, nutrients from human urine could serve as substitutes for at least 37% of the nitrogen and 20% of the phosphorus demand that is currently met by imported artificial fertilizers.
What's the problem with urine in wastewater?
While urine accounts for less than 1% of total wastewater volume, it contains 50–80% of all the nutrients in wastewater. Many micropollutants, i.e. residues of pharmaceuticals and hormones from human metabolism, also enter wastewater via urine. On average, for all medicines and hormones ingested, 60–70% of the active ingredient is excreted in the urine.
85-90% of the nitrogen and 50-80% of the phosphorus are concentrated in the urine. These nutrients are desirable in agriculture, but not in waterbodies. It may therefore make sense to separate urine from wastewater and use it for fertilizer production.