https://en.wikipedia.org/wiki/Aachi_%26_Ssipak
https://www.imdb.com/title/tt0972542/
Maybe those researchers have been inspired from that movie. Ah, how life imitates art...
The plot (highly NSFW by the way):
"Somewhere in the future, mankind has depleted all energy and fuel sources, however they have somehow engineered a way to use human excrement as fuel. To reward production, the government hands out extremely addictive, popsicle-like "Juicybars" to citizens, which in turn also makes them constipated. Aachi and Ssipak are street hoodlums who struggle to survive by trading black market Juicybars. Through a chain of events involving their porn-director acquaintance Jimmy the Freak, they meet a porn star named Beautiful, who gets a pink ring inside her butt which makes her defecations rewarded by exceptional quantities of Juicybars. For that reason, Beautiful is also wanted by the violent blue mutants known as the Diaper Gang (led by the Diaper King), the police (most notably the cyborg police officer Geko), and others."
So it seems like a commonish theme.
I am happy to see a growing number of headlines about "rethinking" human waste management at any scale. Flushing toilets with potable water seems just very wrong, and a luxury I always thought western societies can afford only.*
The system that the article describes is a funny one, or at least is sold with humor ("get paid as you poop"). Apart from the technology itself, I think a good amount of being easygoing on the topic is important here: as how sex sells clothing, fart jokes sell novel feces-recycling systems!
Another example (no affiliation) is Kompotoi here in Switzerland:
https://www.kompotoi.ch/ (English available)
I was honored to do a particular type of business on these $5.000 toilets in the Swiss alps at 6.500ft, and admittedly felt like a king sitting on the throne of recycling!
Bottom line: drinkingwater-flushed toilets are not sustainable, nor accessible/affordable for the majority of the world, so let's stop being ignorant and seek for solutions.
Happy pooping!
* disclaimer: I grew up in Eastern European countryside, with no daily access to water flush toilets until I was around 8yo
It was genius! So simple and cheap yet effective. An interesting side effect is that after you flush the toilet the sink's faucet runs for quite a long time, which really makes you appreciate how much water is going in to each flush. Why don't all toilets work that way?
> https://www.cnbc.com/2017/11/16/body-of-north-korean-defecto...
Also, human feces can contain anti-biotics and other stuff that you shouldn’t be spreading over soil. There is a reason why hospital waste water gets special treatment before disposed of into the sewers.
I don’t think using human feces as fertilizers is a good idea.
See more on wikipedia about fertilization using human feces [1] and in general, applications of composting toilets [2].
[1]: https://en.wikipedia.org/wiki/Human_feces#Use_as_fertilizer
[2]: https://en.wikipedia.org/wiki/Composting_toilet#Applications
I assume the cost and potentially even environmental impact of reusing existing potable water infrastructure to provide water for toilet-flushing is much less than manufacturing, installing & maintaining separate local systems (to collect rainwater, etc) for this purpose.
There are still places on this planet where clean drinking water is a scarcity, and therefore - along multiple other reasons - water-flush toilets and accompanying infrastructure cannot be (easily / justifiably) built.
However, as we can see there are different solutions to the problem itself (health-risk free, humanic way of taking a dump) without using up gallons of water.
Source (in Romanian, published by an investigative reporter): https://recorder.ro/harta-apei-contaminate-din-satele-romani...
The most famous surviving example is next to The Savoy hotel on The Strand [https://www.historic-uk.com/HistoryMagazine/DestinationsUK/F...]
Why do it this way? Uses no water while not allowing the accumulation of smelly material. But why seal the product into bags?
The waste needs to be disinfected before it can be disposed of in a casual manner. And ideally the smell should be neutralized. I think the best way to do this is by heating it up. Incinerating your poop every time you poop is too energy intensive. Instead, you can save up the bags and then burn them in large batches. Or send them off to be processed elsewhere.
I'd use a squat toilet in my house if it had some kind of air lock. Maybe like the Tidy Diaper Pail. https://www.walmart.com/ip/Tidy-Diaper-Pail-Pearl/900658925 Pure frikkin genius.
MFCs (Microbial fuel cells) are waiting to feast on all manner of horrible stuff and produce energy. I'm not sure where economic incentives for peeing and pooing would go long term though.
Can it be used as a manure or is it safe to be dumped underground or in rivers?
Absolutely! A danger of human waste is that it carries a lot of pathogens that might be benign or beneficial in the lower intestine of one person but cause disease in the stomach of another, but the solution to that problem is to let it ferment/decompose for a bit and let all the bacteria kill themselves off through starvation and cooking in their own metabolic heat, and during that process is when you collect the methane. You'll often see large piles of cow manure composting in big piles for similar reasons, though the methane isn't always captured.
The danger to dumping any kind of waste into a river, treated or not, is that it will start killing anything that finds it toxic (most likely your fish and amphibians) and feed anything that finds it nutritious (algae, bacteria), which can cause ecological imbalances and generally screw up your ecosystem. For an adjacent example, look at the Gulf dead zone caused by fertilizer runoff from the American corn belt: Fertilizer feeds algae, which then chokes out other plants fish need to survive and absorb oxygen when the algae dies off, leaving a large swath of ocean without fish or anything that relies on fish.
https://www.forbes.com/sites/christinero/2019/07/06/from-fec...
IIRC the problem was that they were using improperly treated waste.
In some cases it might be worth it or necessary, in others I think the process of processing & delivering potable water could be made (or is already) so efficient that building & maintaining separate infrastructure for non-potable water would be a net negative both in terms of cost and environmental impact.
[0] https://www.reuters.com/article/us-northkorea-unicef-idUSKBN...
In practice there is a reservoir where the "almost clean" waste water (i.e. what comes out of the bath sink, bidet and shower/bath tub) is accumulated.
Toilets are fed by a pump with water coming from this reservoir, in practice you use the same water two times.
I’m guessing it never took off because we don’t have that much of a water shortage in most places that washing hands is a luxury.
Note this was many years ago...