A Miniature Sanitation System in a Box
July 22, 2019
In many countries such as the United States, using the bathroom ends with a flush. But for the billions of people around the world that don’t have that luxury, open defecation or substandard restroom facilities create health challenges. Untreated human waste mixes with water sources used for drinking, causing illness and disease. The burden of poor sanitation is particularly high for women and girls, who suffer increased violence and harassment when seeking safe places to go to the bathroom, and who shoulder the responsibility of securing drinking water for their households. The World Health Organization estimates that 525,000 children under the age of five die each year from diarrheal illnesses linked to poor sanitation, and many more miss school and work due to sanitation-related illnesses.
In 2011, the Bill & Melinda Gates Foundation ignited a challenge to this issue by initiating the Reinvent the Toilet Challenge, funding and working with researchers around the world to create innovative approaches for the safe and sustainable management of human waste. The challenge aims to develop a single system that:
- Removes germs from human waste and recovers valuable resources such as energy, clean water and nutrients.
- Operates “off the grid” without connections to water, sewer, or electrical lines.
- Costs less than US $.05 per user per day.
- Promotes sustainable and financially profitable sanitation services and businesses that operate in poor, urban settings.
- Creates a truly aspirational next-generation product that everyone will want to use—in developed as well as developing nations.
Answering this challenge, Duke University’s Center for WaSH-AID worked with the R&D team at MSR to create the Reclaimer, a stand-alone human liquid waste processing unit designed to rapidly treat blackwater – wastewater from toilets – to ISO 30500 standards. Developed in partnership with Cranfield University and Triangle Environmental, the Reclaimer is the result of years of iterative research, development and production by the collaborative teams at these organizations.
Smart Device Combines Trusted MSR Technologies
The Center for WaSH-AID approached MSR for their expertise in early prototyping and product development, including technologies for water treatment. The scientists in MSR’s water research laboratory have hands-on experience with nearly every water treatment technology available to modern science.
Essentially a miniature sanitation plant in a box no larger than a closet, the Reclaimer combines three treatment modalities into a compact, automated system for use in households or community toilet facilities. First, liquid waste with the bulk of the solids removed by coarse separation and settling enters the Reclaimer and is pumped at high speed through the ultrafiltration unit—a nanoporous plastic membrane that takes out the remaining suspended solids and turbidity. The liquid exiting the ultrafiltration unit passes through an activated carbon filter that removes the soluble organic material responsible for color and odor. Finally, the liquid moves to another tank, where the chlorides from the urine are converted into chlorine, using a technology similar to that found in MSR’s Community Chlorine Maker. This electrochemical treatment disinfects the liquid, resulting in clean, safe water. This clean water can safely be reused in other applications such as flushing, irrigation or washing.
The Reclaimer operates automatically, processing batches as needed to reduce power consumption. Using smart technology, a computer-programmed “brain” controls all functions, constantly reading, monitoring, and reacting to the processes inside the device.
Putting the Reclaimer to the Test
As with any prototype, the Reclaimer needs to be tested beyond the laboratory to prove its effectiveness and fit for the communities it will ultimately serve. The device is currently in field trials in India, where the team from Duke University is monitoring its performance.
“We know from our testing at Duke University that this system works really well,” says Brian Hawkins, Research Scientist at Duke University’s Center for WaSH-AID. “What we’re trying to do with field trials is test the technology in the field to see how well it can handle stress, real use, and the unexpected.”
For the billions of people around the world who don’t have access to modern sanitation solutions, the Reclaimer is a game-changer. By processing and sanitizing human waste in a small footprint and without the need for costly infrastructure, the device disrupts the current stream of pathogens that leach from open toilets and into water. By preventing the contamination of drinking water around the world, the technology has the potential to save lives, increase gender equality, and increase economic output through the creation of safer, healthier communities.
Photos by Brian Hawkins