Champaign, Illinois – The future link between human waste, sanitation technology and sustainable agriculture is increasingly clear. According to research by the University of Illinois Urbana-Champaign Civil and Environmental Engineering Teacher Jeremy guestCountries could get closer to using human waste as fertilizer, closing the cycle for more circular and sustainable economies.
A new study describes the spatial distribution of nutrients derived from human urine (nitrogen, phosphorous and potassium) and the demand for agricultural fertilizers to determine supply and demand patterns, their global spread and implications for resource recovery. The results were published in the Journal of Environmental Science and Technology.
said Geist, who also serves as co-director of research at Institute of Sustainability, Energy and Environment In the U. de I. “Everything that enters through food and drink must exit through urine, faeces, and sweat. Knowing this, we can estimate the amount of each of these nutrients in a population’s body waste if we know their diet.”
Previous studies by Geist et al. have assessed the potential for nutrient recovery from human waste around the world and identified places with an excess of nutrients derived from human waste compared to the local demand for agricultural fertilizers.
“The new study is the first to describe the relationships between supply and demand for nutrients derived from human waste using a single mathematical equation,” Geist said. The quality of sanitation infrastructure varies greatly around the world, as does the diet of people and the availability of suitable land for agriculture. Having the means to quantitatively identify and compare nutrient recovery potential can go a long way in informing decision makers regarding future agricultural and sanitation policies. “
The team conducted large-scale numerical and geographic analyzes of food, population, health and agriculture data from 107 countries to perform this quantitative characterization on a global scale. The research revealed three different patterns of supply and demand: countries with a common supply and demand; Countries with displaced supply and demand; Countries with proximity to supply and demand.
The United States and Australia, for example, fall into the joking supply and demand classification. They have extensive cultivation in areas far from large cities, Geist said, so the supply of nutrients derived from human waste is far from where it is needed. Even with a well-developed sanitation infrastructure, this means that nutrients must be transported over long distances, either as heavy liquids or converted into concentrated crystal products. Economically, Geist said, it would make sense to work with a concentrated producer to implement compost derived from human waste in these countries.
The study notes that in countries with balanced supply and demand patterns, such as India, Nigeria and Uganda, human populations are closer to agricultural areas, making local reuse possible. However, in many supply and demand communities that share the same building, there is a need to improve sanitation infrastructure. The guest said that implementing a fertilizer program derived from human waste can be very beneficial for sanitation and agriculture in these places.
Countries such as Brazil, Mexico, China and Russia show a continuum of co-location of changing the supply and demand of nutrients. The study suggests that policy makers should address the use of nutrients derived from human waste with more regional strategies and a variety of local reuse and transport approaches. “High-income countries in this group may have the infrastructure and financial support for different technologies, but those with limited financial resources will need to prioritize resource recovery technology in some areas,” Geist said.
The team was surprised to discover that the models closely matched United Nations Human Development Index.
“Countries with higher HDI scores such as the United States, Western Europe and Australia tend to fall into the jostling supply and demand ranking and countries with lower HDI scores tend to conform to the co-location pattern of supply and demand. Of course, there are exceptions, but we have not We expect to find such a strong association,” Geist said.
The team hopes that this research will help clarify the salient economic, health, and agricultural characteristics of countries around the world, so that decision makers can prioritize investments, policies, and technologies that advance circular economy goals and provide sanitation for all. .
Desarae Echevarria, a former graduate student in civil and environmental engineering from Illinois, is the study’s lead author.
This study was supported by the University of Illinois Urbana-Champaign Graduate Scholarship, the SURGE Scholarship from Grainger College of Engineering, and the Graduate Distinguished Scholarship in Civil and Environmental Engineering.
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