Poop could be a significant part of a circular economy

It is a great resource for many fields

Sustainability seems the approach we should take in the years to come to reduce waste, and poop has the potential to be employed in many fields: medicine, fertilizer, biomethane, recycled water, etc…

Not only on Earth but also in space. According to Steve Sepka, project manager for the NASA Ames Research Center’s Trash Compaction and Processing System. One goal is to produce polymers from organic waste that could be used in planetary surface missions as well as propulsion systems for spaceflight.

The space agency had first considered making fuel from materials found on Mars for a return trip. However, NASA is now debating whether using waste from the astronauts’ own crew may actually help them launch.

According to a CNN article, scientists have proposed that the density of molecules in wastewater could provide a solution for shielding crewmembers from dangerously high radiation levels in space during an extended mission. A NASA plan with many uses, called “Water Walls Architecture“, imagines a spacecraft lined with numerous water compartments as well as treated trash that is used as radiation shielding. Water is the main component of both urine and feces, and compared to metals, water has a higher density of cosmic ray-blocking nuclei due to its closely packed hydrogen and oxygen atoms.

According to Peter Guida, a scientist at Brookhaven National Laboratory in New York and the liaison biologist for NASA’s National Space Radiation Laboratory, a water-based shield could be effective at blocking radiation rays.

Imagine now that wastewater treatment facilities on Earth also serve as multifunctional resource recovery facilities. Researchers are making progress in creating secure and biodegradable bioplastics from currently available waste streams as an alternative to plastics generated from fossil fuels, for instance.

According to Zeynep Cetecioglu Gurol, an associate professor of industrial biotechnology at the KTH Royal Institute of Technology in Stockholm, Sweden, producing eco-friendly bottles, containers, and other bioplastic goods from what we leave behind is still a work in progress. Even yet, finding a cost-effective way to turn wastewater into new goods could reduce the amount of time, money, and effort treatment facilities must invest in order to fulfill discharged water quality regulations. It’s a win-win situation, she claimed.

Anaerobic digestion is a microbe-dependent method that many wastewater treatment facilities now use to convert sewage into biomethane gas, a sustainable fuel substitute. Researchers Cetecioglu Gurol and others have discovered that the organic compounds produced during the biogas production process make an excellent source of carbon for the production of bioplastics. The current objective is to increase production efficiency. But she said we are still in an early stage.

Some bacterial species spontaneously make polyhydroxybutyrate (PHB), a kind of bioplastic, as they consume organic matter. According to tests, PHB can replace a number of petroleum-based polymers and, unlike them, degrades quickly in a typical environment.

Researchers like Kung-Hui Chu, a professor of environmental, water resources, and coastal engineering at Texas A&M University, have been interested in a bacterial strain known as Zobellella denitrificans ZD1. Chu and colleagues have found that the strain, which generally thrives in mangrove wetlands, can also flourish on glycerol (an industrial byproduct), wastewater, and sewage sludge. It is a viable option for converting garbage into bioplastics or other useful goods like fish food due to its capacity to accumulate PHB when growing in such a variety of settings.

Sewage solids that have been cleaned are nevertheless frequently burned or buried worldwide. But even if the amount of ash produced by incinerating waste is reduced, it is still frequently disposed of in landfills. Researchers are working hard to figure out how to turn the solids and ash in this area into valuable products.

Many bricks could be produced by such recycling procedures. Engineers at the Royal Melbourne Institute of Technology in Australia are working to reduce the environmental impact of digging up clay soil to make bricks, in part by experimenting with the incorporation of biosolids, or treated sewage solids, into fired bricks. If creating poop bricks seems like an odd use, keep in mind that animal excrement has been used for ages to create pottery and build homes.

Clay bricks with varied proportions of processed biosolids from Melbourne residents weren’t quite as durable as their conventional counterparts after being burnt for 10 hours at close to 2,000 degrees Fahrenheit. Although they were indistinguishable in terms of appearance and odor, they were lighter and better insulators. Theoretically, bricks built with at least 15% biosolids might still exceed engineering criteria while theoretically recycling the millions of tons of residual feces, according to a 2019 paper by institute civil engineer Abbas Mohajerani and colleagues.

Another team of scientists at the Melbourne institution conducted a follow-up study that provided evidence that raw biosolids, biochar (charcoal derived from biosolids), and burned sewage sludge ash could all be employed as cement substitutes. Other researchers in the UK have proposed that it would be feasible to reuse sewage sludge ash in tiles and glass ceramics as well, with the potential for a variety of building industry applications.

In fact, using a mixture of cow pie and clay, the Museo Della Merda in Lombardy, Italy, has already produced terra cotta tiles, flowerpots, and dinnerware. It is known as Merdacotta.

Of course, the yuck factor may be a bigger deterrent for consumer goods made from recycled feces, such as bioplastic cups, and ceramic plates. However, the harsh conditions of outer space and the growing difficulties in resource extraction on our own planet are assisting researchers in discovering a wealth of raw materials that could support exploration and boost investments in sanitation infrastructure by turning waste streams into income.