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Q:
What is the green / blue staining on bathroom fixtures,
clothes and hair?
A: The source of the green or blue stains is copper which
is leached from copper piping by naturally acidic water.
The problem is most noticeable in the hot water recirculation
loops in high-rise buildings. Use a detergent (such as
Tide) for laundry as anything made of pure soap (such
as Ivory Snow) will make the staining worse as the soap
precipitates the copper out of the water. As part of any
Drinking Water Treatment Program, the implementation of
a pH and alkalinity adjustment (corrosion control) will
substantially reduce this problem.
Q:
I have red stains in my sinks and other fixtures. Kindly
advice any help.
A: Red stains are normally caused by iron in the water.
You must test to determine the amount and the type of
iron you have. Some types are: oxidized, soluble, colloidal,
bacteria or organic-bound. All are a problem! It only
takes 0.3 ppm to stain clothes, fixtures, etc.
Oxidized:
This type of iron is usually found in a surface water
supply. This is water that contains red particles when
first drawn from the tap. The easiest way to remove
this type of iron is by a fine mechanical filter. A
cartridge type filter is usually not a good solution,
due to the rapid plugging of the element. Another method
or removal is by feeding a chemical into the water to
cause the little particles of iron to clump together,
and then fall to the bottom of a holding tank, where
they can be flushed away.
Soluble:
Soluble iron is called "clear water" iron.
After being drawn form the well and contacting the air,
the iron oxidizes, or "rusts", forming reddish
brown particles in the water. Depending on the amount
of iron in the water, you may solve this problem with
a water conditioner, or a combination of softener and
filter. You may use an iron filter that recharges with
chlorine or potassium permanganate, or feed chemicals
to oxidize the iron and then filter it with a mechanical
filter. You can sometimes hide the effects of soluble
iron by adding chemicals that, in effect, coat the iron
in the water and prevent it from reaching oxygen and
oxidizing.
Colloidal:
Colloidal iron is very small particles of oxidized iron
suspended in the water. They are usually bound together
with other substances. They resist agglomeration, i.e.,
the combining together of like substances forming larger,
heavier, more filterable ones, due to the static electrical
charge they carry. This iron looks more like a color
than particles when held up in a clear glass, as they
are so small. Treatment is usually one of two: Feed
chlorine to oxidize the organic away from the iron,
thus allowing agglomeration to occur, or, feeding polymers
that attract the static charge on the particles, forming
larger clumps of matter that is filterable.
Bacterial:
Iron bacteria are living organisms that feed on the
iron found in the water, pipes, fittings, etc. They
build slime all along the water flow path. Occasionally,
the slimy growths break free, causing extremely discolored
water. If a large slug breaks loose, it can pass through
to the point of use, plugging fixtures. These types
of bacteria are becoming more common throughout the
United States. If you suspect bacteria iron, look for
a reddish or green slime buildup in your toilet flush
tank. To confirm your suspicions, gather a sample of
this slime and take it to your local health department,
or water department for observation under the microscope.
This type of iron problem is very hard to eliminate.
You must kill the bacteria, usually by chlorination.
You must use high amounts of chlorine throughout your
plumbing system to kill all organisms. You may find
it necessary to feed chlorine continuously to prevent
re-growth. A filter alone will not solve this problem.
Organic
bound: When iron combines with tannins and other
organics, complexes are formed that cannot be removed
by ion exchange or oxidizing filters. This iron may
be mistaken for colloidal iron. Test for tannins; if
they are present, it is most likely combined with the
iron. Low level amounts of this pest can be removed
by use of a carbon filter, which absorbs the complex.
You must replace the carbon bed when it becomes saturated.
Higher amounts require feeding chlorine to oxidize the
organics to break apart from the iron and cause both
to precipitate into a filterable particle.
Q:
I have blue or green stains on my fixtures. Kindly suggest
any help.
A: You either have copper in your water supply, or you
have copper pipes and corrosive water. Test for copper
in your water. Test the pH, total dissolved solids content
and the oxygen content of your water.
Copper:
Copper can be removed by ion exchange, i.e., a water
softener. The removal rate is about the same as it is
for iron.
Copper
pipes and corrosive water: If your pH is from 5
to 7, you may raise it by passing the water through
a sacrificial media. By sacrificing calcium carbonate
into the water, the corrosively will be reduced. If
the pH is below 5, you will need to feed chemicals into
the water. If the corrosively is caused by excess oxygen,
the hot water will be much more corrosive than the cold.
Treatment is by feeding polyphosphate or silicates to
coat and protect the plumbing, or to aerate the water
to release the excess oxygen.
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