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Urine—a problem as waste, great as fertilizer

Urine—a problem as waste, great as fertilizer

Urine—a problem as waste and great as fertilizer. Urine could be taken out of the wastewater and then used as fertilizer. This could reduce the amount of nutrients that end up in water bodies. It also makes things more sustainable by using common waste items.


Nitrogen and phosphorus that are in our waste streams in too high of a concentration can cause algal blooms. These are bad for marine and lake ecosystems and for people’s health.

Even though it only makes up one percent of all wastewater, human pee is the source of the majority of the nitrogen and phosphorus that are found in wastewater. This is according to the Rich Earth Institute, which is a firm located in Vermont that is focused on harnessing human waste as a resource.

Urine might be removed from municipal wastewater treatment facilities. This would result in the removal of 75 percent of the nitrogen and 55 percent of the phosphorus. And after that, the nutrients might be used as fertilizer after being recycled.

The challenge is in fighting against established systems that are accustomed to the way things are. Wastewater infrastructure is built up to get waste out of the house without much consideration. This is done by utilizing pipelines that already exist and toilets that people are familiar with.

Urine diversion would need some modification of some of these particulars. This is while putting the material that was diverted to use would call for a greater recognition of waste as something of value.

According to Abe Noe-Hays, co-founder of Rich Earth, the statistics on urine’s place in wastewater are what got the ball rolling on urine diversion. Urine diversion is an attempt to keep urine out of the waste stream in the first place.

Urine—a problem as waste, great as fertilizer

Human anatomy is utilized in the construction of a toilet that redirects pee. When a person is seated on the toilet, urine has a tendency to go toward the opening at the front of the bowl. However, feces gravitate toward the opening at the rear. Therefore, the urine is collected in the front half of a divided toilet bowl. These may be sent to a separate drain that is solely for urine.

However, the rear half of the bowl continues to be linked to a wastewater treatment system as is customary. Urine travels via a separate network of pipes before entering a collection tank. It’s possible that this system isn’t foolproof. You’ll need to have good aim if you use it while standing, and you’ll need to install some additional plumbing. However, improving the functionality of the infrastructure that’s already there can help it work better.

The World Health Organization has criteria for how long pee should be held. That is before it can be used as fertilizer. These restrictions are in place in the event that fecal admixture is even a remote possibility. According to Noe-Hays, when pee has been left at room temperature for six months, it has enough self-sanitized to be used on anything, including raw vegetables.

The most important thing to remember about urine is that, if it consists just of pee, it may be used as a source of nitrogen and phosphorus-rich fertilizer. This is as soon as it is expelled from the body. However, it is essential to achieve a satisfactory separation.

Urine partially sterilizes itself

According to Bjorn Vinners, a professor of environmental engineering at the Swedish University of Agricultural Sciences, the most common source of pathogens found in collected pee is feces. He stated that urine-diverting toilets aren’t ideal and that there will always be some urine mixing.

Isolated beforehand, urine has the potential to partially sterilize itself. Urea, a simple organic molecule, is the form in which nitrogen exits the body after being excreted in urine. Ammonia is generally produced when urea is degraded by bacteria that live in pipes.

The pH of the solution is increased to somewhere between eight and nine when urine is allowed to sit in a container for some time. Vinner’s says that a high pH environment is all that’s needed to kill any germs in the body that may have gotten into the urine.

Noe-Hays made a reference to the lengthy shelf life of urine when he stated, “It’s like a Twinkie.”

Noe-Hays took part in a research project that analyzed the levels of medications found in people’s urine. Ibuprofen and caffeine were among the most widely available and prevalent substances.

However, following the application of urine to the soil, the level of drug content in the crops dropped to an incredibly low level. According to the study’s results, a person would have to eat one pound of pee-fertilized produce every day for almost two thousand years to get the same amount of caffeine as in one cup of coffee.

Garden usage of urine

In addition, urine is frequently used as a form of fertilizer in gardening. Noe-Hays has found that it is quite effective in his own gardening endeavors. According to Noe-Hays, the concentration of nutrients in pee does not need to be very high for it to be utilized as fertilizer. What’s really important is the bulk of its individual components. If one were to dump one thousand gallons of urine over an acre, this would add around fifty pounds of nitrogen.


According to Noe-Hays, the same effect could be achieved. This is by the application of merely one hundred gallons of a concentrate. It has to be ten times more potent than urine that has been diluted. “The hay doesn’t care if you apply the concentrate or the dilute,” he added. “The hay doesn’t care what you put on it.” “The only thing that matters is the total number of pounds of fertilizer it receives.”

It is helpful to make use of the capacity to concentrate urine. That is, if one wants to utilize it as a fertilizer for something other than a personal garden. According to Noe-Hays, a spinoff company of Rich Earth called Brightwater Tools is working on developing a method to concentrate urine by freezing it.

When pee is frozen, the water is removed, leaving behind a slurry that can be utilized locally. It can also be transported to a field to be used for crop fertilization. It is easier to deal with the volume of urine if it has been concentrated. This is especially true in settings where pee-diverting toilets are installed. These are in commercial or office buildings. Rather than requiring repeated trips from pee-specific vehicles to empty the tanks.

Concentration Hardware

The concentration hardware enables the urine to be cleaned, pasteurized, and freeze-concentrated on-site. This eliminates the need for frequent tank emptying. The concentration levels reached a factor of 10 during the tests. This indicates that the collection trucks may only need to arrive once every few months rather than every week.

Vinner’s brought up dehydration as an additional strategy for turning pee into a helpful fertilizer on a larger scale. A portion of his study focuses on finding ways to prevent the breakdown of urea that takes place in pipes. If urea does not decompose, the nitrogen will remain solid after dehydration. This yields a dry fertilizer containing 15 to 20% nitrogen.

Producing a dry product would allow him to capitalize on the infrastructure already in place. That is to manage chemical fertilizer, which is one of the advantages he sees in going that route. Dry fertilizer may be applied with machinery that already exists, and storing it is as easy as stacking bags one on top of the other in a warehouse.

According to Vinners, urine is a frequent kind of fertilizer in Swedish gardening. However, outside of that practice, the practice is not nearly as widespread. He stated that it was either a new way of thinking or an old way of thinking in a new way.

The treatment of waste water was initially implemented with the intention of removing filth and illness from urban areas. The development of early sewer systems helped to alleviate that difficulty. However, the societal assumption that waste would always be managed has been a driving force behind a variety of other problems that are far more difficult to solve.


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Environmental impacts

The vast number of individuals who have a requirement for wastewater treatment is one of these issues. When there is an excessive amount of garbage, the surplus is thrown into the environment, and the natural processes that attempt to clean it up are not completely effective.

According to Vinner’s, this can result in high waste concentrations, which can then induce environmental impacts. Some examples of these effects are dead zones in the ocean and eutrophication of lakes.

The solutions are frequently difficult to implement and prohibitively expensive, particularly in smaller areas. According to Lynn Broaddus, president of Broadview Collaborative, a sustainable water services company based in Minnesota, “Whenever there is a problem, they get a cookie-cutter solution. The cookie-cutter solution is a centralized wastewater treatment plant.”

Urine diversion is a whole new way of thinking about environmental issues, but it has the potential to alleviate many of the problems that are caused by wastewater treatment facilities that are at capacity. According to Broaddus, even if the goals are good, low-income and minority populations are frequently not as open to new ideas as they should be because of fears that they are being used as Guinea pigs. This is the case even when the motives are genuine.

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Climate Change worries

Concerns about climate change have given a lot of attention to water, and Broaddus has noticed that more people are becoming interested in alternatives for treating tiny amounts of wastewater and in creating a circular water economy. According to Broaddus, the more people that are able to understand the system, the more manageable it will become. Wastewater has a lot to offer, including energy, nutrients and information.

By tying together a few loose ends, urine diversion may be included in a closed-loop water economy. It’s possible that the water that people drink and then defecate will eventually be used to fertilize the veggies that are being prepared for a salad.

Changes in how people think about it and how it’s set up are two important next steps that need to be taken for farmers and gardeners to use it more often.

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