By: Amanda Froelich,
Campaigns commonly ask for plastic, aluminum, and clothes to recycle, but urine is definitely a first. In effort to find alternatives for natural fertilizer, Amsterdam has created an initiative which will recycle human urine to maximize plant growth and save energy on sewage treatment.
While the topic may make some squeamish, reprocessed waste water has increasingly gained traction as a sustainable fertilizer; it has been shown to promote plant growth, and if produced and dispersed in large-scale applications, may save energy on sewage disposal.
Launched by Amsterdam’s city utility company, Waternet, the program Green Urine is currently collecting urine from residents to fertilize rooftops across the city. Avoiding the awkwardness going door to door could stir, Waternet has instead set up rows of temporary urinals in one of the city’s public squares. Once it’s collected, the urine will be processed to extract its phosphates, turning them into struvite, a powdery substance used as fertilizer. The struvite will later then be dispersed across several acres of rooftop garden.
Traditional phosphate fertilizers have been used since the 1800’s, but the global dependence on them to grow our food has many concerned that the Earth’s resources are being depleted. This concern could easily be alleviated by sourcing the compound from human urine, which is why pee-cycling is receiving praise for its resourcefulness.
According to environmental scientist Helvi Heinonen-Tanski in Scientific American, “It is totally possible to use human urine as a fertilizer instead of industrial fertilizer.” Along with making agricultural methods more sustainable, utilizing urine-based fertilizer has the potential to help boost food production and heighten sanitation in developing countries. This may be particularly relevant in small communities where waste water treatment simply isn’t available.
Not all believe that phosphorous is a resource the world needs to be concerned about, however. Some argue that we have about 300 years’ worth of phosphorous in our reserves, while others strongly believe the planet could run out within the next century. Regardless, if the ability to recycle and re-use is within humanity’s ability, it should be utilized to reduce stress on the planet and save resources.
Waternet isn’t the first to jump onto the pee-cycling bandwagon. In 2007, researchers in Finland actually went door-to-door collecting urine from locals. The untreated waste water was then used to successfully fertilize small crops of vegetables such as cucumbers and cabbage -all which were reported to taste delicious.
The city’s campaign doesn’t stop in the streets. The Green Urine campaign is also a test case for the sewage treatment plant Waternet is set to open up next year. It will feature a dedicated collection center for human waste water and researchers have a goal of collecting urine samples from 1 million Amsterdam residents. This amount could produce 1 million tons of fertilizer annually.
With the pee-cycling breakthrough, chemical engineers at the University of Florida have also joined the cause. They successfully tested methods for extracting phosphorous from urine before it had a chance to reach the sewage system, where it can become diluted and difficult to collect. Their goal was to inspire the use of diverting systems, such as waterless urinals and composting toilets, both of which could cut down on water usage and simplify waste streams.
The method of pee-cycling has been proven to pose no health risk and offers new solution for reducing humanity’s taxation on the planet. Perhaps next time you feel your vegetable garden needs ‘perking up’, you’ll consider this rather unorthodox fertilizer.