Its a quirk of human beings that certain research topics are neglected because of their proximity to humor. Whether its the hydrodynamics of the penis, or the musculature of the vagina, or the mechanics of excretion. Unless its funny, we reject whole areas of investigation as unworthy or repulsive.
There are so many urine tests I can't count them. But how many over-the-counter poop tests are there? Maybe one. Because, you know, its disgusting.
The issue is probably all the contaminants in human poo, especially medical: anti-bacterials, hormones, radioactive tracers. Maybe it isn't so much purifying the phosphate that matters, but removing components that would be bad to recirculate into our food chain.
Serious and funny - to me - are not mutually exclusive. The idea of wombats stacking their poop is very funny, but if I was a biologist, that would make me want to investigate the matter even more.
During my Zivildienst (https://en.wikipedia.org/wiki/Zivildienst), I had lots of contact with all kinds of things leaving the human digestive tract. You get used to it surprisingly quickly, as long as you have and endless supply of rubber gloves and disinfectant. OTOH, the revulsion feces inspire in most humans serves a purpose, evolution-wise, so finding a middle ground would be rather difficult.
Errr.....no? Human waste in water is a major cause of disease. Sure, a turd or two won't be a problem. And sure, it'll decompose. But all kinds of pathogens remain. There are billions of people, and as the eponymous book says: everyone poops.
I didn't even want to joke about that on HN, but it did cross my mind. Find a happy healthy person and (somehow) ask them for some fecal matter and do a transplant. Or just start licking butts... ugh
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