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Given how often animal manure was used as fuel for fires in the past, I'm surprised that most people didn't pre-burn their dried feces before using it as fertil
by bilegeek 4y ago
Given how often animal manure was used as fuel for fires in the past, I'm surprised that most people didn't pre-burn their dried feces before using it as fertilizer.
I get why - it's too much extra work - but I would've figured it would be seen as worth it; provides fuel for fires, removes the stench, and makes it easier to spread on the crops.
(I know they weren't aware of germ theory, but even then I figured they would see advantages.)
- deepdriver 4y agoWould combustion affect poop’s fertilizing qualities, or spread bad stuff around in the steam and smoke?
- masklinn 4y agoAssuming the point is mostly nitrates and minerals, I don’t think they would be would be much affected, though the aggregation properties of the manure may be? On the other hand, combustion could also help with destroying the antibiotics found in the manure, which spread to the soil and accumulate in produce.
- masklinn 4y ago(Obviously that’s a modern manure issue, not historical).
- deepdriver 4y agoDid some searching, looks like pyrolysis can convert waste into biochar in way that eliminates pathogens: https://www.susana.org/_resources/documents/default/2-1832-2-1624-von-herzen.pdf https://www.susana.org/_resources/documents/default/2-1832-2... >Complete elimination of pathogens from Human Solid Waste (HSW) is a priority of our biochar reactor. By heating an appropriate flow of input material to high temperatures above 450 C for about 15 minutes, the material thoroughly chars, causing a 100% elimination of pathogens. Doesn't say anything about heavy metals or pharmaceuticals. In particular I don't know whether heat can denature or destroy birth control hormones like ethinylestradiol. If it's suspended in water, it can be removed through a reverse osmosis or activated charcoal filter. Maybe leaching before charring and filtering the runoff would help? Dunno.
- deleted 4y ago[deleted]
- riffraff 4y agoI am not sure human feces burn as well as herbivore manure. Cow and horse feces look pretty different from human feces, drier and "herbal", and I would be surprised if they share the same combustive properties. Sheep/goat/rabbit also seem naturally much drier than human tho I've never investigated their internals :) Edit: on a second thought, cow shit is not particularly dry
- bongoman37 4y agoSun dried cow shit is still used as a fuel source in India. You can even buy it on Amazon [1]. [1] https://www.amazon.in/Fresh-Cakes-Religious-Purpose-Handmade/dp/B0B8JZ7CZ4/ https://www.amazon.in/Fresh-Cakes-Religious-Purpose-Handmade...
- noduerme 4y agoWow. There's something absurd about selling dung branded and in bubble wrap.
- xhevahir 4y agoA lot of people there put it on the walls of their houses, too, for reasons that aren't clear to me.
- bongoman37 4y ago
- 4y ago
- biorach 4y agoIt's quite hard too dry out faeces in the British climate. It's common in hot countries.
- sampo 4y ago> I'm surprised that most people didn't pre-burn their dried feces before using it as fertilizer This paper is about incineration of sewage sludge. They consider incineration at temperatures like 700C to 900C. Seems like you end up burning 98% of the nitrogen, which is then released as gas (bottom of page 12, just before Conclusions). The output ash only contains 2% if the input nitrogen. Kind of defeats to point of using the output as fertilizer. https://sci-hub.se/https://doi.org/10.1021/acs.energyfuels.5b01109 https://sci-hub.se/https://doi.org/10.1021/acs.energyfuels.5...