Clean
Drinking Water for Everyone
(April 30,
2012) Nearly 80
percent of disease in developing countries is linked to bad water and
sanitation. Now a scientist at Michigan Technological University has developed
a simple, cheap way to make water safe to drink, even if it’s muddy.
It’s easy
enough to purify clear water. The solar water disinfection method, or SODIS,
calls for leaving a transparent plastic bottle of clear water out in the sun
for six hours. That allows heat and ultraviolet radiation to wipe out most
pathogens that cause diarrhea, a malady that kills 4,000 children a day in
Africa.
It’s a
different story if the water is murky, as it often is where people must fetch
water from rivers, streams and boreholes. “In the developing world, many people
don’t have access to clear water, and it’s very hard to get rid of the
suspended clay particles,” says Joshua Pearce, an associate professor of
materials science and engineering. “But if you don’t, SODIS doesn’t work. The
microorganisms hide under the clay and avoid the UV.”