Low-Cost, Portable Toilet Inspired by Evapotranspiration in Plants

Innovation: Industry

change:WATER Labs

2020

Capture, Absorb, or Filter Liquids

The most common liquid used by living systems is water, which they require to survive. But there are many other liquids that provide nourishment, play a role in defense mechanisms, or serve other purposes. Water varies in its availability; it is sometimes plentiful and sometimes very scarce or only available as fog or mist. To minimize the energy required to capture, absorb, or filter liquids, living systems have strategies that take advantage of the unique properties of the given liquid. For example, water moves from a gaseous to liquid state when it encounters a surface colder than the air. Plants in forests that experience fog and clouds more than rain have strategies that condense liquid water from moist air.

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Store Solids

Living systems, especially organisms, must sometimes store solids, often pieces of material (such as mud, seeds, stones, or leaf fragments). They use these solids for building structures, feeding during periods of low food availability, or other purposes. To be effective, the storage strategy must be appropriate to the sizes of solids and to the media in which they exist, whether air, water, or other solids like soil. It must also safely arrange the solids for storage in a location appropriate to either short- or long-term storage. An example is the Clark’s nutcracker, a forest bird that can collect up to 150 pine seeds and temporarily hold them in an expandable pouch under its head, where it doesn’t interfere with the bird’s daily activities.

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iThrone from change:WATER Labs uses evaporation to dispose of human waste without using energy or plumbing.

Benefits

Reduced water use
Reduced waste
Improved sanitation

Applications

Refugee communities
Rural communities
Residential buildings

UN Sustainable Development Goals Addressed

Goal 3: Good Health & Wellbeing
Goal 6: Clean Water & Sanitation
Goal 10: Reduced Inequalities
Goal 11: Sustainable Cities & Communities

The Challenge

Globally, 2.6 billion people lack safe toilet access. Chronic under-investment into sanitation infrastructure means people in many poor and vulnerable communities live with their sewage. Within the 40% of the world who lack proper access to sanitation, a deeper problem lies for women and girls. 20%-40% of girls drop out of school because of inaccessible or inappropriate toilets. In many areas, women and girls are at risk of violence with their current solution. In addition, refugees, indigenous groups, and communities in need that are completely off-grid are left with few ineffective – often dangerous – options to deal with their lack of proper sanitation. In many camps and disaster-relief arenas, aid agencies struggle to mount acceptable responses to the immediate pressures of providing safe sanitation. For the growing number of post-crisis situations in urban and coastal areas, which displace around 25-50 million people per year, there are no good options for rapid-response sanitation.

Innovation Details

changeWATER: Labs has developed a new way to dispose of human waste by evaporating out the water. These low-cost, portable toilets use a simple membrane to rapidly evaporate 95% of sewage without using any type of energy. This provides homes with a working toilet, without the need for power or plumbing. The compact, contained, stand alone units can be dropped into any space quickly, and the ‘self-flushing’ technology works while being completely waterless and environmentally safe. This technology emerged from work done for NASA on wastewater recycling on the International Space Station, and is now being deployed in off-grid rural and refugee communities.

Watch how change:WATER Labs was inspired by plants to create a more sustainable toilet.

Biological Model

This evaporative approach to “flushing” by change:WATER Labs mimics the natural process of evapotranspiration, where plants pull water from the soil up through the plant, where it evaporates through the stomata on their leaves.

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Biological Strategy

Leaf Pores Draw Water Through Plants

Plants

Pores in leaves allow water to escape as vapor, drawing more water up through the plant from the roots.

Ray of Hope Prize

The Ray of Hope Prize® celebrates nature-inspired solutions addressing the world’s biggest environmental and sustainability challenges. Created in honor of Ray C. Anderson, founder of Interface, Inc. and a business and sustainability leader, the $100,000 Ray of Hope Prize helps startups cross a critical threshold in becoming viable businesses by amplifying their stories and providing them with equity-free funding. The prize shines a light on the innovative, nature-inspired solutions that we need to build a sustainable and resilient world. change:WATER Labs was selected as a finalist for the 2020 Ray of Hope Prize.

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