Ada sesiapa tahu bagaimana untuk membersih air yang
berlumpur untuk selamat dijadikan minuman dan masakan dengan cara yang paling
mudah dan murah? Artikel ini dari penyelidik di Michigan Technological
University mengatakan garam biasa boleh menjernihkan air.
Kalau ada idea yang mudah dan murah ini, perlu difikirkan
dan dikaji untuk kemudahan mangsa banjir di pantai timur.
Clean Drinking Water for Everyone
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.
Thus, to purify your water, you first have to get the clay
to settle out, a process called flocculation. Working with student Brittney
Dawney of Queen’s University in Ontario, Pearce discovered that one of the most
abundant minerals on Earth does this job very well: sodium chloride, or simple
table salt.
Salt is inexpensive and available almost everywhere. And it
doesn’t take very much to make muddy water clear again.
“The water has a lower sodium concentration than Gatorade,”
Pearce says. This would still be too much salt to pass muster as American tap
water, but American tap water is not the alternative.
“I’ve drunk this water myself. If I were somewhere with no
clean water and had kids with diarrhea, and this could save their lives, I’d
use this, no question,” he says.
Salt works best when the suspended particles are a type of
clay called bentonite. The technique doesn’t work as well with other kinds of
clay. However, by adding a little bentonite with the salt to water containing
these different clays, most of the particles glom together and settle out,
creating water clear enough for SODIS treatment.
