Starting with the end in mind: Nitrogen

[Riventree]

Hello everyone. I've just begun researching composting, and I was surprised that googling "composting forum" actually came up with pages of results for forums, much less for posts on the subject, so I'm a bit overwhelmed. There is a huge body of (very dispersed) knowledge out there, but most of it seems to be oriented toward producing generic fertilizer rather than a particular set of chemical components.

Likewise, should one dare to search amazon books for "composting", there are a veritable plethora of sources. Unfortunately they too are focused on the resulting mixture and levels of K, P, Ca, and other nutrients taken as a whole.

What I'm looking for is information which can take me towards a composting system where mammal urine goes in one end, and a liquid stream rich in soluble nitrates exit the other. The other components (methane, solids, etc) are completely secondary.

I see MANY general texts, webpages, etc., out there. I've familiarized myself with a lot of them. Can anyone recommend a text, paper, webpage, or expert who might take me "the next step" toward my goal?

Thank you for your consideration,
-Riventree

[rainbowgardener]

Why do you want this? Why are you focusing only on the N?

Most of us do general composting, trying to include as much diversity of materials as possible, because plants need not only NPK but a whole bunch of micro/trace nutrients and minerals and vitamins and the microbiology to help them make use of it all.

Plant nutrition when you start to understand it better is a living, complexly interactive, system that is based in biology, not in chemistry. Just giving your plants a few chemical elements is not really feeding them.

[DoubleDogFarm]

Not sure if this is what you are asking about. This video is large scale, but maybe there is a DIY or small scale system out there.

https://www.youtube.com/watch?v=vHQ2O9PsNM4

Eric

[Riventree]

Wow, what a great bunch of responses. I hope we can get somewhere from here.

The short version of the reason that I'm doing this project is: I have a stream (no pun intended) of urine on the order of 10-100L per day, and I'd like to turn it into something useful rather than dumping it down the drain.

Ammonia is one possibility: Drop in some urease from soybeans and capture the ammonia via air-stripping. Simple, but there are two downsides: First, the volume doesn't change much (urine -> NH4(aq)) Second, leaks are smelly.

On the other hand, if I can further bioconvert the urine/ammonia to nitrates, those can be dried and transported easily, and have no odor in the case of a leak in the system or the transport.

Please keep the ideas coming! I'm open to any suggestions out there, in terms of chemistry, physical setup, "right" compost mix, temperature, etc.

All help welcomed thankfully

[rainbowgardener]

The simple solution is pee on your compost pile!


(Or in case you are female like me, pee in a jar and dump it on your compost pile.)

[Riventree]

Um, rainbow, that's exactly what I want to do. I have 10-100L of urine arriving each day, and I want to design a compost pile that can turn that into something useful. My understanding is that you won't be able to flush (no pun intended) that much through a 55gallon drum composter, nor will I have a lot of NON-urine waste to balance it out, so I'm asking for scaling, design, temperature, composition, etc. advice.

I'm pretty sure this isn't a trivial question, even though I feel like you've dismissed it as such twice now.

-Riventree

[applestar]

What about neutralizing the other biologicals? Is there any chance of bio-hazard contamination? Infectious organisms?

A possible non-chemistry oriented processing method can be found at fungi.com (Fungi Perfecti) in one of their articles -- Paul Stamets proposed a mushroom bed to filter agricultural/farm animal run-off. ...but it sounds like that's not when you are talking about? You want to create a "product" rather than simply neutralizing?

[rainbowgardener]

OK sorry, I think the last time through I missed the 10 to 100 L PER DAY! Wow! I was thinking more of the 10 L or less a week a person might produce.

So here:

https://www.treehugger.com/green-food/pe ... lizer.html

are some people adding magnesium oxide to liquid urine to turn it in to a powdered fertilizer.

[ElizabethB]

RB

Thanks - I needed that

[Dillbert]

>>10 - 100 L per day

okay, that's
2.642 gallons to 26+ gallons of urine per day.

no individual human / human pair produces that much urine.

some part of this story is not being told.

[rainbowgardener]

yeah, took me awhile to get that. " I have 10-100L of urine arriving each day, " that is arriving from elsewhere. This isn't "home-made" urine Not even specified if it is human.

[Riventree]

Yes this is definitely NOT a for-my-home project. It's a case of "I have a chunk of land, upon which people and animals spend some amount of time each month, which I'd like to handle in an environmentally sound way" The solid waste is already accounted for, and the liquid is something I'd rather treat than dump.

I really haven't meant to be "sneaky" or hold anything back... what other info do you need?!?

So far the MgO additive looks best: it crystallizes the majority of the solutes in the urine and leaves the water relatively clean. I had originally expected to compost it, or de-ammonify it (as I talked about above) but maybe in this case chemistry is the answer.

Seriously: If you guys need any more info, just ask! I'm all ears.

-Riventree

[applestar]

Not sure if you are interested, but I found the article and relevant paragraph that made me think of it:

At our farm which included a small herd of Black Angus cows, I established two King Stropharia beds at the heads of ravines which drained onto a saltwater beach where my neighbor commercially cultivates oysters and clams. Prior to installing these mushroom beds, fecal coliform bacteria seriously threatened the water quality. Once the mycelium fully permeated the sawdust/chip beds, downstream fecal bacteria was largely eliminated. The mycelium in effect became a micro-filtration membrane. I had discovered that by properly locating mushroom beds, "gray water" run-off could be cleaned of bacteria and nitrogen rich effluent. Overall water quality improved.

https://fungi.com/blog/items/permacultur ... twist.html

A little different, but this is apparently one of their newest projects:
https://fungi.com/blog/items/mycofiltrat ... nding.html

[Riventree]

Excellent data. Perhaps that could work as well. Mushrooms don't take that much maintenance.

[rainbowgardener]

You said people and animals.... for the people part of it, I am a big believer in composting toilets, which handle both the solid and liquid wastes.

Where I used to live we had a big fancy (expensive) one with heated tray to dry the resulting product and fan assisted vent. It is a big electricity consumer, which seemed to defeat some of the green/ lower your footprint usefulness of it. You can do a simple bucket system, inexpensive and no power.

[Dillbert]

veddy interstink . . .

regrets my experience is limited to dairy barns, it all gets scooped into a pile or drains into a tank thenceforth to be spread on the fields....

zero.zip experience with chemically treating urine/liquid components to make them more "instantly useable" - typically a bit of aeration 'solves' that problem....