Sequestration
Sequestration is
a technique to prevent a contaminant such as iron from precipitating from the
water. This solution does not remove the contaminant but ties it up,
hampering it from oxidizing and fouling the water supply.
Polyphosphates keep iron in
solution by stabilizing and dispersing the iron so preventing it from
oxidizing.
Considerations
When Polyphosphate treatment is
initiated it exerts a dispersing action on old deposits of iron from within the
system. Frequent flushing of pressure tanks and hot water system may be
required.
Heating, such as by hot water
tank or cooking can cause reversion of Polyphosphate to a simpler phosphate
compound, which has no sequestering ability, thereby losing its ability to
keep iron from oxidizing.
Polyphosphates are only
effective in the control of dissolved iron. They will not control
precipitated iron, organic iron or iron bacteria.
Testing should be done first.
| 
