NoMix toilets make a splash in European study
By Ben Coxworth
March 14, 2010
If you’ve ever considered the humble urinal, you might have noticed that it uses much less water than a toilet. It only makes sense - since they don’t receive any feces, urinals don’t need all the water necessary to carry such solid waste through to the sewer line. When you use a toilet and just urinate, however, you’re still flushing away just as much water as if you, uh, went “Number 2.” If you were using a NoMix toilet, however, the Number 1 and Number 2 would go separate places, with the flushes being needed for solid waste only. It’s a good enough idea that in a recent pilot project, users in seven European countries gave the device a thumbs - or should that be bottoms? - up.
The NoMix has what is essentially a urinal in the front half of the bowl, near the top. The urine runs from there to a storage tank. The back half of the bowl is like a conventional toilet, where the solid waste lands and gets flushed away.
The pilot project was conducted by the Swiss Federal Institute of Aquatic Science and Technology. It included feedback from 2,700 NoMix test-pilots in Switzerland, Germany, Austria, Luxembourg, The Netherlands, Sweden and Denmark. The results showed that around 80 percent of users liked the idea, while 75 - 85 percent were satisfied with the design, hygiene, smell, and seating comfort.
The obvious advantage of such a system, as already mentioned, is the conservation of the water that would have been used in urine-only flushes. Its good points don't stop there, however.
By keeping urine out of the sewage system, wastewater treatment plants would reportedly have 80 percent less nitrogen and 50 percent less phosphorous to process... or more accurately, to try to process. The pharmaceutical residues present in urine would also be largely kept out of the waterways, where they presently pose a threat to fish and other wildlife.
Instead of being flushed, it is proposed, the urine could be used as an agricultural fertilizer. What, you think that sounds kind of gross? Apparently, 85 percent of the NoMix users don’t think so. Farmers, however, aren’t so keen on the concept - only 50 percent of them liked the idea, while only 34 percent said they would use or purchase such a fertilizer.
The bugs in the system
Indeed, there were some noted drawbacks to the NoMix. For the waste separation to work most effectively, men needed to sit down to pee - God forbid! And when women were finished with a urine-only sitting, they needed to do something with their used toilet paper other than flush it. Overall, 60 percent of the users encountered problems of some sort, most notably phosphate precipitate blockages in the urine drainage system.
Hopefully, this kind of feedback will lead to a more user-friendly NoMix, which will in turn lead to less pollution and water wastage. The full report on the project can be read at the website of the scientific journal, Environmental Science & Technology.
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