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."'"

Comments

Night Soil

[ObsessiveMathsFreak]

I believe "nightsoil men" used to sell the human waste they carried away to tanners and farmers. In any case, the idea of using human waste as fertiliser is very a very old one. The massive wastage of human sewage is probably a modern phenomenon.

Re:Night Soil

[Savage-Rabbit]

I believe "nightsoil men" used to sell the human waste they carried away to tanners and farmers. In any case, the idea of using human waste as fertiliser is very a very old one. The massive wastage of human sewage is probably a modern phenomenon.

Not entirely but the extent to which we fail to recycle human excrement and urine is quite new. Many ancient societies used human waste for fertiliser although that can be a health hazard. In Roman times tanners, people who dyed cloth and other such businesses actually had pissoires outside their shops and big signs inviting customers to please come over and relieve themselves. Apparently tanners and dyers processed the urine to get Ammonia rich solutions which they used to prepare their products. I remember a QI episode where Stephen Fry dropped this fact-bit about how the House of Lords in London used to reek of stale piss on rainy days because of the quantities of urine used to in the production of tweed fabric which was popular with the upper classes in the late 19th and early 20th centuries

Re:Night Soil

[K. S. Kyosuke]

The night soil was untreated, though, and therefore extremely dangerous for public health. Also, they were dealing with feces, and urine is less dangerous even when untreated.

Re:Night Soil

[retroworks]

The nightsoilmen (toshers) processes, while imperfect, were much less toxic than what they were replaced by - Whitehead's flush toilet (which drove them out of business). The outflow from flush toilets in London were directed into the same dry pits as the toshers worked from, making the pits impossible to manage. With no downstream plan for the new flush toilet technology, "The Great Stink of London" came from the stormwater runoff into the Thames, which caused thousands of death in cholera epidemics.

You are right, the work should not perhaps be romanticized, but was not given any incentive to improve... it was flushed away by the new million dollar flushable toilet technology industry. The fact is that the toshers/nightsoil industry created better than average pay in London, certainly much better than blackleg coal mining. But the marketers of "flush toilet technology" stigmatized them, and the sewage treatment plants of today are seen by many in the environmental community as a "correction" to a technological advance. http://retroworks.blogspot.com...

During the mid 1800s another "technological advance" was the sale of mercury as a laxative. I guess it gives great bowel movements (Lewis and Clark's expedition can be tracked today by the mercury laxative residue - they ate a lot of elk and not much fiber). What I find fascinating are the parallels between the toshers and the past decade of private sector electronic waste management. Most of the "export market" buyers of used CRTs turned out to be not primitive wire burners but factories formerly licensed by Proview, BenQ, Wistron, Foxconn etc., which were purchasing very specific models of CRT for refurbishment and sale to markets like Cairo, Lagos, Jakarta and New Dehli. Like the nightsoil workers, they were flooded with product and then denigrated as "primitive recycling". The CRTs were diverted to a shredding industry designed for scrap metal. Leaded glass cullet doesn't shred well, and the glass diverted from reuse private markets still lies around. At one of the largest sites, in Hallstead PA, floodwaters engulfed the CRT cullet piles twice in the past decade, leading to the closure of the recycling facility last summer. http://resource-recycling.com/...

Re:The chemistry works out...

[mellon]

From the FAQ:

What about pharmaceutical residues in the urine? When we take prescription or over-the-counter drugs, a portion of the dose passes through us unchanged and is excreted in our urine. When we use flush toilets that are connected to sewers, these residual drugs pass largely unchanged through the treatment plant in about twenty-four hours and then go directly into rivers, lakes, or the ocean, where they can harm sensitive aquatic life and end up in our drinking water. If we spread the urine on agricultural land instead, the robust soil ecosystem has a chance to break down the drugs and biodegrade them over a much longer period of time, greatly reducing or eliminating their levels before they ever reach a body of water. In this way, soil application is a great improvement over current practice. On the other hand, plants have the ability to absorb some pharmeceuticals, which could potentially affect people eating crops grown with urine. We plan to investigate pharmaceutical levels in crop plants and, if necessary, test methods of removing pharmaceuticals from urine before using it as a fertilizer.

Re:Ick is right

[SirGarlon]

Not just illegal drugs, either. Antidepressants have been found in urban drinking water supplies.

Real numbers: urine-to-bread conversion analysis

[Noe-Hays]

Here's an analysis we did on how many pounds of wheat (and loaves of bread) could be grown using only the fertilizer contained in one person's yearly urine output. This figure didn't make it into the National Geographic article, but it's really important for understanding the potential for urine recycling to replace synthetic fertilizers at a large scale. Of course urine-derived fertilizer could be applied to any other food or non-food crops, but we thought the huge pile of bread was the more accessible measure.

And if you look closely at the numbers, you'll see one of the most surprising things of all: that nearly 90% of the nitrogen (and 2/3 or better of the potassium and phosphorus) in human waste is in the urine!

Abe Noe-Hays, Research Director, Rich Earth Institute