Transcript Diapositiva 1

Today, we call ourselves highly developed and with the
growth of industrial sector pollution has growth to a whole
new level. Huge amount of pollution leads to
contamination and contaminated water leads to diseases.
So now the question here is can the old basic filtration
methods still produce the best drinking water or we need
something else? Are more intense purification methods to
combat the modern contaminants in our water supply
needed?
The answers to these questions could be found by
analyzing and comparing the traditional and modern water
filtration methods.
Boiling
From ancient times, boiling is what has been
used to disinfect water from microorganisms. In
fact, when done correctly, it can kill most
bacteria, but not all. Bacteria and protozoa are
killed at the first bubble, and it takes about three
minutes to kill the rest.
However there are a few drawbacks here.
• It can require lots of fuel and cooking equipment.
• Water cannot be used immediately, as it needs to cool
down.
• Since the boiling water is so hot, some of the water may
evaporate before its use.
• The water can still contain particles. So further filtering
through a handkerchief could be necessary.
• Finally, boiling water does not eliminate chemical
pollutants (including chlorine), poor taste of foul odors,
and in fact can leave a stale taste.
Chemical
There are two primary chemicals used to purify
water: iodine and chlorine. Both these chemicals are
lightweight, low cost and easy to use. Iodine has
been proven effective in killing off viruses, bacteria
and protozoa. However, the colder the water is, the
more time it will take to purify with iodine. Iodine can
also absorb into the dirt and debris naturally found in
water, so the dosage will always vary. Also, pregnant
women or those with thyroid conditions cannot not
drink water with the chemical. Usually, iodine is just
used for short-term purposes, and should not be
used for more than three consecutive months. Also it
leaves a taste behind that is not favored by many.
Chlorine bleach is the second chemical purifier. The process of
chlorination causes dirt and debris to settle to the bottom of the water
container and making the water visually clearer. When using bleach to
purify, it is recommended that one adds 16 drops of bleach per gallon of
water, stir, and let stand for 30 minutes. If the water does not have a
slight bleach odor, one needs to repeat the dosage and let stand
another 15 minutes. There are many drawbacks to the chlorination
method. If the household bleach is over six months old, it may not have
enough potency to disinfect. Also, chlorine is very poisonous and
adding too much can cause illness, internal organ damage or even
death. Chlorine has been linked to many health problems. Also, if one
decides to use bleach, be sure to add it at the time intended to use the
water, not when storing.
Seeing the drawbacks of these traditional filtration methods brings us to
understand why more advanced water purification are required
nowadays.
Water filtration by definition simply means to
strain out the impurities from a water source. It
is believed that larger the impurity particulate,
the easier it is to filter. However, the truth is the
smaller the impurity particulate, the harder it is
to remove. Thus, the size of the filter pore and
the durability of the filtering element are
important to the filter's longevity and its ability
to perform. Most filtering elements are made of
ceramic, glass fiber, hard-block carbon, or
materials that resemble compressed surgical
paper.
Reverse osmosis is highly effective in removing several
impurities from water such as total dissolved solids,
turbidity, asbestos, lead and other toxic heavy metals,
radium, and many dissolved organic. The process also
removes chlorine, and nuclear radiation such as radioactive
plutonium or strontium in the drinking water.
Therefore, reverse osmosis combined with activated
carbon seems to be the most advanced water purification
method developed till date.
ADDRESS:
D - 11, Diamond Park, G.I.D.C. Naroda,
Ahmedabad - 382 330.