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Water & Sanitation in Africa

Water & Sanitation in Africa

According to the World Health Organization, “2.4 billion people do not have access to any type of improved sanitation facility. About 2 million people die every year due to diarrheal diseases; most of them are children less than 5 years of age.” The United Nation’s Millennium Development Goals Report from 2012 states that “sanitation coverage increased from 36 per cent in 1990 to 56 per cent in 2010 in the developing regions as a whole. Despite progress, almost half of the population in those regions … still lack access to improved sanitation facilities.” As sanitation goals remain out of reach, the associated health hazards and poor living conditions persist.

Unfortunately, established sewage system standards in developed countries do not provide a feasible model for developing countries which do not have sewage infrastructure, lack the economic means to build and sustain such elaborate systems, and do not have the water required to operate them. Resolving the sanitation issue in developing countries will require new, innovative sanitation solutions.

The Water, Sanitation and Hygiene program of the Bill & Melinda Gates Foundation has identified the sanitation challenge as their top priority. The foundation fosters the development of new technologies and tools that can help deliver sustainable sanitation where it is needed. As part of this strategy it is funding numerous investigations into a wide variety of potential technologies by universities and commercial entities worldwide. In April, 2013, Duke University received a ‘Reinvent the Toilet Challenge’ grant from the Gates Foundation to develop a demonstration unit for community scale sewage treatment. 

The project is being led by Marc Deshusses of Duke University’s Department of Civil and Environmental Engineering in collaboration with Jay Golden of Duke’s Center for Sustainability and Commerce and the Carbon Recycling Center, led by Bill Jacoby of the University of Missouri’s Biological Engineering Department.

Dr. Golden and students have been conducting field research in South Africa examining informal settlements and rural schools where there are needs to provide water and sanitation solutions.  Two of our key partners in South Africa are the University of KwaZulu-Natal in Durban as well as the eThekwini Municipality.

The Technology

The Gates Foundation diagram above depicts a sanitation solution that starts with the individual and the toilet, includes the storage, transportation and treatment of human waste, and ends, ideally, with safe, usable byproducts such as fertilizer, fuel or clean water. Engineers at Duke University and the University of Missouri are designing a unit that addresses the treatment of human waste and possible reuse of the system’s byproducts. It will sanitize the collected waste of approximately 1200 people—a neighborhood-scale solution. The goal of this project is to produce a demonstration unit that fits into a 20 ft. shipping container and will be ready for testing in a developing country by summer 2014. A successful design will have a running cost of less than 5 cents per person per day at commercial volumes.

The technology being employed to meet this challenge, supercritical water oxidation (SCWO), is promising because it works quickly and generates energy in the forms of hot water and steam from the treatment of human waste. Furthermore, it does not require prior dewatering or drying of fecal sludge, and it effectively eliminates all types of harmful organisms. SCWO technology has already been implemented in several research and commercial applications to treat waste products, including polychlorinated biphenyls (PCBs), chemical weapons and sewage sludge. Duke and the University of Missouri seek to demonstrate that both SCWO and supercritical water gasification (SCWG), a related technology, have prominent roles to play in solving the world’s sanitation challenges. In addition, we will produce a business model plan that quantifies and optimizes the economic, environmental and social benefits of the unit. 

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