Human waste could be biofuel

It's not enough just to keep human excrement out of water supplies and other places where it's not welcomed. Not putting it to practical use is, well, a waste.

Now a Columbia University professor of environmental engineering has teamed up with a social enterprise in Accra, Ghana, to turn "fecal sludge" into biodiesel or methane fuel. The project, called the “Next-Generation Urban Sanitation Facility,” is in cooperation with Waste Enterprisers and is being underwritten by a recently announced $1.5 million grant from the Bill & Melinda Gates Foundation.

“We are delighted to be awarded this project,” says Dr. Kartik Chandran in a news release from Columbia University. “And we are especially pleased that the Gates foundation has recognized the critical importance of sustainable sanitation by investing in our pioneering project. Thus far, sanitation approaches have been extremely resource- and energy-intensive and therefore out of reach for some of the world’s poorest but also most at-need populations. This project will allow us to move forward and develop practical technologies that will be of great value around the world.”

Half the people in the developing world – some 2.5 billion people – lack access to safe sanitation, according the Gates foundation. "1.2 billion people practice open defecation, meaning they have no sanitation facilities at all, and 1.3 billion people use unsafe latrines. Most of these people live in rural areas, but as urbanization increases, the crisis is spreading to towns and cities as well."

Human excrement is "a concentrate of organic material with high energetic value," the Gates foundation says. "Energy can be derived through digestion, extraction, or combustion, simultaneously reducing the volume of sludge that must be disposed."

The Gates foundation is focusing on improving sanitation in poor regions, seeing it as one of the "Grand Challenges" facing the world.

Dr. Chandran and his partners are developing methods to convert organic compounds in human waste into usable fuels. That will keep the waste out of the environment, where it's a contributing factor to disease, and provide an alternative fuel source.

Chandra's work is part of a project by Engineers without Borders, which taps engineering expertise to address human needs.

The world is experiencing a "sea change" in the way human waste is regarded and used, Chandra says. "In fact, the term ‘wastewater’ is already archaic," he says. "Wastewater is, after all, just water with a different chemical and biological composition."