| 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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