Separating urine from sewage could mitigate some environmental problems
nature.com
nature.com
In order to clean the toilet bowl, people will use highly poisonous cleaning solutions. How will these cleaning solutions mixed with the stored urine affect its usage as a fertilizer? Even if it is eventually dehydrated, wouldn’t some of the cleaning solution still be present?
What happens if you send other types of fluid down the “urine only” toilet or system (ie, blood, vomit)?
People will even flush drugs, dead pet fish, alcohol and other non-human waste products down the drain.
In theory, it sounds like a great way to reduce our carbon footprint. But if they are designing the system on the assumption that people are smart and will only use it as intended then it might actually cause the opposite effect.
An interesting implication of that is that bacteria will break down parts of the urine into ammonia, and a little bit for feces but not as much.
If someone were to dump bleach into it, it might create chloramine gas. Emphasis on might there; I'm in no way qualified to evaluate that risk.
I do see the space for a septic system designed for rotation - ie that uses a pipe material designed to last X number of years that then itself biodegrades, and can be ploughed and the field used once a sufficient safety fallow period has passed.
(That and they're acknowledging that people who haven't chosen composting toilets tend not to like them, because the separating takes some getting used to and if you don't separate urine from faeces the decomposition is much slower and smellier)
Once my compost bin is fully built, I let it sit for at least 1 year.
The only thing to be really concerned with is certain chemotherapy drugs. Some of them not only don't break down in a compost pile, but they can cause cancer in people who don't already have it.
The composting process is pretty amazing. It's vastly more hygienic than sewage (lol).
PFCs may accumulate almost regardless, although I assume composting helps. After all, composting can break down gasoline, diesel, and TNT - though of course you shouldn't add them to a compost bin! Quoting The Humanure Handbook (4th edition) page 115: "About half the sewage sludge (biosolids) produced in the USA is applied to land, providing a significant opportunity for contaminants to enter soil systems and to bioaccumulate over time..." And page 117: "For example, brominated fire retardants were still found at almost eight thousand times higher concentrations than background concentrations in soil samples twenty years after the last application of biosolids. In another study, fifteen out of nineteen pharmaceutical drugs were still present in soil six months after being irrigated with contaminated wastewater."
So PFC accumulation is already happening but not because of composting. It's happening because sewage sludge is being added to farm fields and new housing developments.
This is part of why I cook with clay (in solar cooking) and stainless steel on the stovetop. That way my nutrient loop (eat, excrete, compost, grow more food) has the absolute minimum of PFCs and other contaminants.
For more information, read chapter 10 of The Humanure Handbook (4th edition) by Joseph Jenkins.
https://www.mainepublic.org/environment-and-outdoors/2022-02...
In my area the majority of contamination is from firefighting foams, and I think in the Bay area there's also a lot in groundwater from semiconductor manufacturing. My understanding is the known way to remove PFCs from soil involves baking at very high temperatures (like 500C) which is impractical at any scale.
Even so, there must be some sort of either precaution or processing steps that can be taken to minimize PFC concentration, although I don't quite know what they might be.
They proposed/demostrated a cycle that is basically
Shower -> indoor plants -> toilet -> outdoor plants
New Earthships capture more energy, water & food at lower cost https://www.youtube.com/watch?v=wVp5koAOu9M&t=1m45s
My one concern is sodium accumulation. There are some thermal approaches based on solubility curves that sort of work. I'd also be interested in electrochemical and, ideally, biological approaches (can we use biological cell membranes and ion pumps instead of manufactured ones?).
Weighing difficulty against impact, this seems under-researched.
I briefly had a project called Pee on a Tree that got mocked and got no traction. This is why Earth is doomed: The simple solutions are derided while people overcomplicate things that don't have to be complicated.
Hoomans: Y'all fools deserve your fate and I shall say so in my dissertation for my degree in Human Studies when I get back to Vulcan.
A related article from Low-Tech Magazine, published in 2010.
The end of that article is kind of sad because it details the reasons these very effective low-tech sewage treatment methods are being phased out, and they are some of the same systemic problems that are preventing climate action worldwide: - low cost of fossil fuels (due to negative externalities) driving out sustainable alternatives - global speculation on real estate / urban sprawl - inadequate regulation of destructive activities
Everything will have to change for our civilization to continue in the face of the climate crisis, we must rethink every system our lifestyle relies upon, sewers included.
No need to bring in outside fertilizer, not flushing hundreds of gallons of potable water per month into the sewer, and I get top-notch compost to use for growing veggies.
And the neurotoxin that does the damage also harms people!
For a little perspective, Tampa bay still hasn't recovered from the last red tide event in 2017 which is evident by the specific fishing regulations implemented for the area.
Huh? We're already producing way too much fertilizer from farm animals, which leads to the situation that countries like the Netherlands [1] and Germany [2] experience a massive oversupply of dung that has to be shipped sometimes hundreds of kilometers because otherwise the fields near the dung sources get way too much nutrients or the dung runoff fucks up river ecosystems.
How about using what we actually have right now in abundance instead of building highly complex systems designed to capture tiny amounts of human urine?!
[1]: https://www.noord360.eu/2021/02/10/guelletourismus-warum-deu...
[2]: https://sz-magazin.sueddeutsche.de/deutschland/drecksgeschae...
Absolutely not. Not all types of diets need fiber for your digestive system to function properly.
Way too many people lack a combination of access to fresh groceries (they live in "food deserts" [1]), enough money to afford these groceries [2], enough time to cook healthy food [3], or skills to cook food [4] - and most often these issues collide in poor and otherwise disadvantaged people... which again are at the highest risk of malnutrition, obesity and associated other health problems.
The thing to tackle is poverty because it sits at the root of all of these issues, not making sugary drinks more expensive - all this does is punish the poor people yet again for being poor!
[1]: https://www.aecf.org/blog/exploring-americas-food-deserts
[2]: https://www.nationalgeographic.com/foodfeatures/hunger/
[3]: https://www.reuters.com/article/us-usa-economy-multiple-jobs...
If you split soda into water and candy, then at least candy intake is visible and controllable.
Soda is not cheap. A 2-liter bottle of Coca Cola contains 900 calories of corn syrup and costs $2 at my nearest Walmart. For the same $2, you can buy a 4lb bag of sugar and get 3400 calories if you don’t care that your calories are coming from sugar.
If you want something that at least kind of looks like food you could get 1200 calories of Chips Ahoy cookies for that $2 and while that’s not good for you, it’s gotta be better for you than soda. $2 will also get you about 1200 calories of Wonder bread or Great Value granola. Or $2 will get you a whopping 1500 calories of Kraft Mac and Cheese. Soda is a shitty deal in terms of calories. Even milk costs less per calorie than Coca Cola. And don’t tell me poor people are mostly buying off-brand cola because it’s not rich people making Coca Cola billions. (And it doesn’t change much because I was mostly comparing equivalent brands. You can get calories from Walmart-branded bread as cheaply as you can from Walmart-branded soda.)
People buy soda because it’s tasty, convenient, and widely advertised, not because it’s cheap calories.
Obese people are also not in need of more calories so the idea that they are turning to soda because they need cheap calories doesn’t make a bit of sense.
> The thing to tackle is poverty because it sits at the root of all of these issues, not making sugary drinks more expensive - all this does is punish the poor people yet again for being poor!
These are orthogonal. You can “tackle poverty” and also make soda expensive. This isn’t punishing people for being poor. It’s placing a tax on a very unhealthy habit to make it less appealing, exactly as we do for cigarettes.
This argument might be compelling if people actually needed soda for the calories, but they don’t.
> skills to cook food [4]
This is an odd choice of article. It says literally nothing about poverty or why poor people don’t cook. It’s just some random survey of adults who say they don’t cook and only 23% of them said it was because they don’t know how anyway. Of those, there is some unknown overlap with the 51% who say their spouse does all the cooking and undoubtedly some overlap with other groups such the group who live at home with their parents and the group who have enough money to always eat out.
That's because most pet food is unhealthy crap - the worst offender is food that has sugar added for optics/smell reasons or grains because they are cheaper than meat. Healthy food for pets stinks and looks bad, so manufacturers add sugar that the humans keep on buying it.
On top of that, most pets don't get nearly the amount of movement they need - their owners don't have the time to take their dog on the two to three hours (!) a day that energetic, former work dog breeds need, or they are being kept solitary... if there is one thing that adopting a pair of kittens has taught me it is that they contain absurd amounts of energy that they burn through playing, and solitary cats can't release it.
The problems I see are unintended consequences [0] of the policy. Perverse results could include additional environmental costs to producing and delivering fiber pills and probiotics (there would still be costs if added to the water). Unexpected drawbacks could include side effects from the fiber and probiotics delivered in this way (especially for people with unusual gut microbiomes, or defects in the production of fiber and probiotic supplements), and civil unrest from people who oppose the mandatory additions to the tap water (which may ultimately result in changes in the nation's political power).
Fiber pills do not reduce waste. They increase it. That is the point of fiber. It increases stool. Fiber is also known as “bulk”.
> Should we be introducing these things into the water supply like fluoride?
This is like asking if we should put protein into the water supply. You can’t just dump a bunch of psyllium husk into the water supply. It won’t make it through the water supply and come out of the tap on customers’ homes. It will just gunk up the city pipes, pumps, etc.
If it did somehow work it would make the water supply disgusting to drink and unusable for many domestic purposes.
That's not very far, we used to ship guano halfway around the world. We don't produce near enough manure to fertilize all of our fields. Certainly we should use the manure we do produce, but it certainly isn't close to enough.
Not all ecosystems admit an excess of nitrogen. Many rare species of wildflowers would be quickly replaced by nettles, elder and other common species and vanish.
>According to Simha’s estimates, humans produce enough urine to replace about one-quarter of current nitrogen and phosphorus fertilizers worldwide; it also contains potassium and many micronutrients (see ‘What’s in urine’). On top of that, not flushing urine down the drain could save vast amounts of water and reduce some of the strain on ageing and overloaded sewer systems.
>In a study[1] that modelled wastewater-management systems in three US states, she and her colleagues compared conventional wastewater systems with hypothetical ones that divert urine and use the recovered nutrients to replace synthetic fertilizers*. They projected that communities with urine diversion could lower their overall greenhouse-gas emissions by up to 47%, energy consumption by up to 41%, freshwater use by about half, and nutrient pollution from the wastewater by up to 64%, depending on the technologies used.
[1] http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&d...
That synthetic is the key. Replacing it makes sense - but why replace current wastewater systems at an enormous price tag with "tech magic" when we could simply use existing supplies of animal dung?
> and reduce some of the strain on ageing and overloaded sewer systems.
ETA: Actually, sewer systems are more strained by not enough wastewater flowing through them - they were designed to the load of many decades ago, prior to the invention of water-saving toilets, showers and other appliances. Now, there is not enough water let in, and the sewage doesn't get swept away - the result is smelly [1].
[1]: https://taz.de/Wasserverbrauch-in-Deutschland/!5032936/
>Urine diversion consistently provides improved environmental performance relative to the conventional system for each scenario for all impact categories, except AP, as shown in Figure 2 (see Table S17 for data plotted in this figure). Both diversion alternatives reduced the GWP, CED, freshwater use, and EP categories from anywhere between 24 and 63%.
As a reality check, there are still tens of thousands of homes in the United States using lead pipes for drinking water. The current regulatory and economic climate has made it infeasible to replace infrastructure that literally poisons people. Any reform that proposes to alter the physical structure of the vast majority of existing residential buildings must necessarily be situated in the context of laws, costs and politics that define what is possible for those buildings, and compared in terms of realistic costs and impact to the scores of other proposals to do similar things.
This is a painful and depressing reality that anyone who has studied American urban development for more than a few months comes to understand.
At the end of the day, humans and animals are both part of a cycle of nutrient use and recycling those nutrients from waste, be that human waste or animal waste, is a way to cut down on synthetic fertilizer use.
Some bits from the USA [0] [1] [2] that y'all might find informative. Important part is that manure comes in different varieties and it's not all a 1:1 replacement for synthetics in the way farmers use them today.
Also of note is that, just like in Germany, parts of the USA that concentrate livestock have too much bull shit and that's bad for runoff from the livestock operations. But that's the expected result, ain't it? Concentrating feed from fields all over means you're concentrating what comes out of the animal also, which means you need to truck it off somewhere or end up with a local pollution problem.
One other upside of pursuing human waste streams is that we already have a lot of infrastructure in place to process human sewage. Have a look at [3] right here and you'll see the potential— but that's still less than half the phosphorous that Europe uses in the present day. Good news is that cutting back on fertilizer input doesn't result in a 1:1 linear reduction in cereal yields so a reduction in fertilizer availability (after the phosphates get mined out) doesn't necessarily lead to a bad famine.
These are complex systems here and there's no one-size-to-fit-them-all type solution.
[0] https://www.ers.usda.gov/webdocs/publications/42731/16741_ap...
[1] https://www.ers.usda.gov/webdocs/publications/42731/16744_ap...
[2] https://www.epa.gov/sites/production/files/2015-07/documents...
[3] https://www.nweurope.eu/projects/project-search/phos4you-pho...
https://www.sciencedirect.com/science/article/pii/S097308261...
You Don't Know Shit https://www.youtube.com/watch?v=ZiNiBZiR_uA https://www.youtube.com/watch?v=EVGdmE4_h4c https://www.youtube.com/watch?v=Ra47l7fihZU
> Using an inoculum acclimated to high ammonia concentrations was critical to successful biogas production at these high TAN concentrations.
That's what this part is talking about. They intentionally introduced bacteria that were tolerant of high ammonia levels to work around all the ammonia the urine gives off. The wild-type bacteria aren't tolerant of those levels of ammonia, and do a poor job of digesting the feces when mixed.
It can contain a lot of recreational drugs, alcohol, prescribed drugs, various other toxins that the kidney is able to sort out.
If a person gets really dehydrated the pee is not good at all. (The body can be pretty fantastic at retaining water if it goes all in. What you pee out in this condition is reasonably toxic and there is little of it. Drinking it "survival tip" is not a good idea since the pee is concentrated and toxic.
Large scale use of human pee may experience odd side effects due to these factors.
Eliminate the entropic, commingling contamination problem by separately collecting 1, 2 and everything else for resource extraction.
They have got to be taking the piss.
So worth the downvotes.
The origin of this phrase (I am certain you know and merely detailing for others) is literally in the once-financially-viable business of collecting urine (from public houses, outdoor toilets, and even private houses) because it was a valuable source of ammonia before the invention of the (from memory, Haber-Bosch?) process for its industrial production.