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Researchers Try To "Close the Nutrient Cycle" Through Better Waste Recycling
An anonymous reader writes "Converting human waste into usable fertilizer may become the next important development in sustainable living. 'Most conventional farms invest in synthetic fertilizer, which requires energy to produce and is associated with many environmental problems of its own. But by separating out human urine before it gets to the wastewater plant, Rich Earth cofounder Kim Nace says they can turn it into a robust fertilizer alternative: a "local, accessible, free, sanitary source of nitrogen and phosphorous."'"
A colleague of mine works on phopshorus (P) removal from waste water treatment plants. In his presentations he always talks about the P lost down the toilet, how much that costs to treat and how much could be made recovering it and selling it for fertilizer, and then throws out the phrase "there's a gold mine of P in there". The crowd never seems to know how to take that.
"The massive wastage of human sewage is probably a modern phenomenon." I can tell you, from a wonderful tour of the Stickney sewage treatment plant outside of Chicago, that in the 70's the solid-waste output was determined to be too contaminated with cadmium to be safe for human food crops. Cadmium comes from the blue dye in jeans, which is washed away in the laundry.
Nowdays, as a poster below has pointed out, pharma and it's metabolites will probably be the challenge.
Abe Noe-Hays here--Research Director at the Rich Earth Institute. One thing I should add is that starting this spring we are participating in a two-year study (headed by the University of Michigan) measuring the levels of pharmaceuticals in urine collected from public toilets, and tracking the movement of those pharmaceuticals into soil, groundwater, and plant tissues. The soil ecosystem is very good at breaking down complex compounds, but some drugs are considerably more resistant to decomposition than others and we are interested to see how they behave. If you want to follow our progress, please sign up for our newsletter! Thanks, mellon, for quoting our FAQ into the conversation.
That's quite a different problem. Cadmium is an element. Pharmaceuticals and their metabolic products are organic, and consist of the same elements as the desired stuff. Unlike cadmium, you can often get rid of them simply by applying high-enough temperatures.
Ezekiel 23:20
To the countries listed in your first link, I'd add Korea. My father was there in the late 1940's with the US Army, and he said human waste was widely used as fertilizer (Korea was a very different place back then). The army even offered their waste to the locals (an offer genuinely meant to be helpful), but the farmers said that Americans used too much toilet paper.
Re your 2nd link, it's interesting that even in 1909 there were Americans who were interested in how there are parts of East Asia where the same fields have been used for millennia, and are quite productive.
Obviously using raw human waste is a major health problem, but processed stuff works great. The National Geographic article mentions urine in specific, apparently because it takes less energy and effort to separate out the useful stuff. It surprises me that it "contains 80 percent of the nitrogen and 55 percent of the phosphorous", because I usually think of manure being used for fertilizer. Does the animal urine go to waste, or is it used by, for example, having livestock graze in fallow fields?