A better way to purify water – use the sun (SODIS)
Dangerous water put in plastic bottles and on roofs in Africa is safe to drink, and tastes better than boiled
Franziska Bosshard confirms that sunlight kills bacteria, but not how
Simplicity and truth triumph in Ron Rivera’s pottery, too, contrary to NIAID policy
Franziska Bosshard at EAWAG Aquatic Research in Switzerland has been investigating the extraordinarily simple way villagers in Kenya have been making their otherwise dangerous drinking water healthy. The villagers pour it into plastic bottles (glass works too) and lay them on the grass roofs of their huts for about six hours in the bright sunlight.
They have done this for eleven years with great success – the fluid, though it is still a rather alarming light brown in color, tastes better than when the water is boiled, they say, and according to Deutsche Welle TV, children have been found in the local clinic to be much less susceptible to water borne disease.
Water quality and drought plague Kenya where the tap water is generally not safe to drink even though Nairobi is Masai for “place of cool waters”. (On the positive side, it is worth mentioning in passing that Kenya is a bird watcher’s paradise, with 1,137 species and 60 bird dense areas where 100 species a day can be counted.)
Bosshard’s group has found that the sunlight does indeed break down offensive bacteria and in about four and a half hours exposure to ultraviolet light in the range 300-400 nm (which appears to be the main agent) they are permanently destroyed, unable to repair themselves when the water is stored.
The inactivation process taking place during exposure of microbial cells to sun and artificial light is now being investigated in our research group. First experiments with Escherichia coli showed that the primary damage of the cells affects transport processes on the cell’s cytoplasmic membrane. Hence, the inactivation mechanism seems to be distinctly different from that caused by UVC light where primarily DNA is damaged. Since a single method cannot give adequate information on the way a cell is injured and finally dying, we are employing a range of different methods to study cell inactivation by sunlight; this includes traditional plating, ATP-content of cells, and several flow cytometry-based methods that can give information at the single cell level.
So far Bosshard has been unable to find out exactly why this occurs, in terms of mechanism. Nonetheless, we nominate her for Environmental Health Scientist of the Year, for confirming that this incredibly simple and cost-free life saving process is scientifically valid.
Given that 2 billion people in the world have no toilets and simply “go” outside somewhere and that diarrhea kills as many as two million children annually, this validation should help save countless lives. Unsafe water and sanitation cause 80 per cent of all sickness and disease, according to this rock-it-up video (soundtrack is Beck “Time Bomb”) from charity:water on YouTube (where it plays smoothly, though not for us at the charity:water site, otherwise the best designed popular Web appeal on this number one global crisis), and 1.1 billion people have no access to safe drinking water:
Scott Harrison finds soul in wells
Of course, there are limitations in the method – chemicals remain, quantity is limited, and two full days are needed if the weather is cloudy – and obviously the best answer is a new well, as the sparkling fresh and clear liquid images in this video, World Water Day Video from charity: water suggest. A contribution of $20 will bring this elixir of life to one person for two decades, promises charity:water.
Founder Scott Harrison, 33, a night club promoter in NYC who decided at 28 he was living a soulless life, has raised with cool graphics and put-yourself-in-their-place ads (showing New Yorkers collecting brackish drinking water from Central Park) $10 million in three years for 1400 well projects at $5000 each. As he says, “Water changes everything!”
However, the Kenyan method at $5000 less than a well is an excellent start, which demands nothing but bright sun and a plastic bottle.
Its simplicity surpasses Ron Rivera and his pottery device which filters enough water daily for a family of six who might otherwise have to drink directly from the polluted rivers and streams of the less developed world. But Ron’s water is clear, we assume, and not light beige, as is the Kenyan water even after treatment by the sun.
Ron Rivera’s pottery
The last New York Times Magazine of 2008, an indispensable annual edition called Lives They Lived, which celebrates the achievements of worthwhile lives that had ended in the year, gave Ron a page, describing how he had died Sept. 3 in Managua, Nicaragua, after contracting falciparum malaria, the most dangerous form, while traveling the world promoting his simple contraption and the factories needed to build it.
Ironically, the same week featured Oprah Winfrey taking a group of American children to Africa where they were horrified and tearful at the sight of the filthy water drunk by the village children they visit, yet there was no mention of this simple solution.
Then one day in October 1998, Hurricane Mitch hit Central America, flooding roads and triggering mudslides, killing an estimated 11,000 people. At home in Managua, knowing how readily bacterial disease follows on the heels of disaster, Rivera remembered an object he encountered years earlier in Ecuador, a simple terra cotta pot that looked like the sort of thing in which the rest of us — the earth’s less vulnerable — might plant our springtime geraniums. Made of clay mixed with some grist — usually sawdust or ground rice husk that would burn off later in the kiln — and then shaped carefully, this pot had thousands of micropores. And those pores, along with a coating of antibacterial silver solution, allowed it to perform a small but significant miracle: removing 98 to 100 percent of the bacteria from contaminated water, making it safe to drink.
Convinced that he could help indigenous potters mass-produce clay-pot water filters for their own communities if the process for making them could be standardized, Rivera began to experiment, calculating the optimal size and clay composition. He then designed a mold for the filter and a special clay press that was operated with a tire jack, which he figured was one of earth’s more universally available bits of technology. Rather than applying for a patent, Rivera posted his work, in painstaking detail, on the Internet. The filter, which costs roughly $15 to make, rests inside a lidded five-gallon plastic bucket with a spigot. It purifies enough daily water for a family of six.
Other sites, however, eg Design for the Other 90, say that a Guatamalen chemist designed an earlier version:
Originally designed by Dr. Fernando Mazareigos, a Guatemalan chemist, the Ceramic Water Filter combines the filtration capability of ceramic material with the anti-bacteriological qualities of colloidal silver. This filter has basic, yet impressive, impact on the lives of the rural poor, dramatically decreasing diarrhea, days of school or work missed due to illness, and medical expenses. A sociologist and potter, Ron Rivera of Potters for Peace redesigned the filter to standardize mass production in sixteen small production facilities in fourteen different countries. It is estimated that over 500,000 people have used the filter.
In other words, there are simple but effective solutions available for the worst plague in the world, filthy water, if only a hundredth of the budget of the absurd and egregiously misguided war on World AIDS was redirected to a proper goal.
With villagers in the Himalayas increasingly out of snow, glaciers and water, however, global warming is bringing on the threat of no water at all in places around the planet, so no doubt the rich will be preoccupied with that next, while the poor languish in neglect except for the rapid delivery of a bounty of misery inducing drugs, courtesy of global celebrities Bill Clinton, Bill Gates, etc.

Qualified outsiders and maverick insiders are very often right about the need to replace received wisdom in science and society. This site exists to back the best of them in their uphill assault on the massively entrenched edifice of resistance to and prejudice against reviewing, let alone revising, ruling ideas. 
The inactivation process taking place during exposure of microbial cells to sun and artificial light is now being investigated in our research group. First experiments with Escherichia coli showed that the primary damage of the cells affects transport processes on the cell’s cytoplasmic membrane. Hence, the inactivation mechanism seems to be distinctly different from that caused by UVC light where primarily DNA is damaged. Since a single method cannot give adequate information on the way a cell is injured and finally dying, we are employing a range of different methods to study cell inactivation by sunlight; this includes traditional plating, ATP-content of cells, and several flow cytometry-based methods that can give information at the single cell level.
Convinced that he could help indigenous potters mass-produce clay-pot water filters for their own communities if the process for making them could be standardized, Rivera began to experiment, calculating the optimal size and clay composition. He then designed a mold for the filter and a special clay press that was operated with a tire jack, which he figured was one of earth’s more universally available bits of technology. Rather than applying for a patent, Rivera posted his work, in painstaking detail, on the Internet. The filter, which costs roughly $15 to make, rests inside a lidded five-gallon plastic bucket with a spigot. It purifies enough daily water for a family of six.
September 10th, 2009 at 9:55 am
Yes, but the fact that it doesn’t remove the chemicals is a big problem, as most developing countries I’m familiar with have big time chemical pollution. We’re more interested in an idea we recently found out about — condensation as a source of drinking water. Whether or not it is pure is a question we don’t have the answer to yet.
http://www.youtube.com/watch?v=OnGR-j93JEw
http://www.opur.u-bordeaux.fr/angl/question1_ang.htm
http://www.google.com/search?hl=en&num=100&q=condensation+drinking+water&btnG=Search&aq=f&oq=&aqi=
Perhaps we can interest those swell humanitarian Bills, Clinton and Gates, in pursuing this promising method of minimizing the misery that will be caused by “Global Warming.” We on this blog do admire the two men inordinately, so perhaps the blogmaster himself might make the approach.