Sunday, August 21, 2011

The Super-Loo

The WHO estimates that 2.6 billion people around the world lack access to a latrine that is not overflowing, that is affordable, and that has a tap nearby to wash hands.  Some one billion people defecate outdoors.  This is the cat method, where feces are rolled in sand or dirt next to the village (my cats utilize the "cat method" - - with the addition of air conditioning, heat, and a roof over their heads). 

The liquid diarrhoea and vomit jetted out by a body infected by the bacterium Vibrio cholerae is a reminder of the danger lurking in the excrement which flows from every human settlement, creating a problem few want to go near.  Not all human waste has the deadly bacterium, but all of it is dangerous and better disposal of feces would go a huge way to stopping cholera and other deadly intestinal diseases (The WHO says that out of two to three million cholera cases a year, 200,000 people die.  The outbreaks are spread over 40 to 50 countries).

Enter the Bill and Melinda Gates Foundation and their mission - - a better toilet.  Where "better" means no connection to a sewer system, no water or electricity, and must cost less than pennies per person a day to use.  The program and competition, "Reinvent the Toilet" has awarded $3 million to researchers at eight universities.  One team, the Swiss Federal Institute of Aquatic Science and Technology (Eawag), utilizes a system to divert and collect urine.  Dealing with urine separately, by siphoning it off to local storage tanks, simplifies wastewater management.  The urine can then be collected, treated, and recycled as fertilizer.  Cost is still an issue, along with little boys having difficulty aiming correctly between the compartments (a universal problem regardless of the loo).

Other teams are working on solar power and electrochemical (regardless of the stated goals, some form of energy is needed to go from Waste A to Usable Product B) technology.  For example, one toilet uses the sun's energy to power an electrode system in the wastewater; the electrodes  drive a series of cleansing chemical reactions, converting organic waste is the water into carbon dioxide and producing hydrogen that can be stored in a fuel cell for night operations.

Not exactly going to the moon, but a super-loo would be rather complex.  Mixing design, engineering, biochemistry, and microbiology - - combined with sociology - - makes this a contest to watch!!

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