When life was literally full of crap
rootsofprogress.org
rootsofprogress.org
A century from now will our descendants be cursing batteries and silicon PV panels? I suspect so.
Agriculture has gotten by with synthetic fertilizers for a while, but N, P, and K aren't everything plants need... they also yearn for the countless micro-nutrients in our bodily wastes which are lost when we flush. And while N (Nitrogen) and K (Potassium) aren't likely to run out any time soon, P (Phosphorus) is in limited supply and finding enough of it for our agricultural needs may become a serious problem later this century. Not to mention the fact that producing NPK fertilizer takes a lot of energy.
Hopefully most of us won't have to give up the flush toilet, but we absolutely will have find better ways of dealing with the "downstream" product and start recovering its significant value. In the not-so-distant future shit will be valuable again.
Is that the standard way of handling sewage?
I have only toured one sewage-processing plant, and I am sure that there are many different types, but that one had huge (as I recall, building-sized) machines pulling all of the solids out of the sewage; this sludge was then loaded on trucks. I do not remember, now, if it was carted to landfills or composted, but of course it could be composted.
Before using it for agriculture one would want to consider whether the medications and other contaminants are a problem.
One cool thing about that plant I remember is that the water it produced was well within drinking-water standards: it could be connected straight to the water system.
We've just removed most of the human shit.