rycee@lemmy.world 8 months ago
What about the nutrients in the waste? Why not compost it, capture the methane offgassing, and store that?
using human waste as fertilizer isn’t a good idea.
human waste contains everything that a person has consumes. this includes disease causing pathogens and parasites.
if it were to be used as a fertilizer it would need to go through multiple stages of expensive processing and testing to ensure safety. it’s far more cost effective and safer to use food by-product like fish cuttings to create fertilizers.
Treated waste water sludge is very commonly used here in Sweden albeit using anaerobic digestion rather than regular composting. High temperature composting would kill any pathogens so you can absolutely get permission to use a composting waste system in small scales. For larger scale waste treatment it is with anaerobic digestion, as mentioned.
The captured methane is typically used for fuel, e.g., in public transport.
As far as I know the sludge used for fertilizer needs to be certified under something called REVAQ. Some controversy does exist surrounding safe levels of the various harmful substances and perhaps PFAS in particular.
Just gotta lie on the questioner:
Has any PFOAS filled American pooped on this toilet in the past process cycle?
That’s a trap question, we’re all PFOAS filled.
Engineer here. We arent talking about directly tossing it on fields. We are talking about having it be anaerobically fermented at high temperatures for about 30 days, with the biogas captured and used for energy.
the new thing to do then is burn the remains and recover the phosphate from the ashes, where certainly no biological threat remains
I’m curious how much phosphate we would be able to capture with this method?
I know it is a critical resource we are flushing away daily and -SHOULD- be doing this. Just like peak oil there is a concept of peak phosphorous.
In the EU recovering phosphor from wastewater could cover about one third of the EU countries total phosphor demands.
This is why the EU made tge strategic decision to have such recovery systems developed and built.
The pathogens are less of a problem. But chemicals from medication and contraceptives, as well as heavy metals, are.
less about infection and more environmental. some people don’t wash their produce and get sick because of it.
Not to forget: It contains a ton of medicine as well. If you want to have antibiotics in your salad, use human waste as fertilizers.
Probably mucroplastics too?
you’re absolutely right, I forgot about those and it’s probably worse than the parasites.
interdimensionalmeme@lemmy.ml 8 months ago
But what do you do with the methane, can’t story it and if you burn it, you release the CO² which was the point of burying fertilizer while it’s CO² carbon credit value is less than the price of the fertilizer itself.