Water Education - Water Quality

Sequestration - Polyphosphates Treatment

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There are, in addition, several other techniques for the control of soluble iron in the water. These make use of polyphosphates to keep the iron in solution.

Polyphosphates do not remove iron from water. Rather they stabilize and disperse the iron so that the water remains clear and does not produce iron stains.

However, polyphosphate treatment may not prevent iron from precipitating when water is boiled for a time, as in cooking or in the brewing of tea or coffee, as boiling can cause reversion to the orthophosphate which has no equivalent sequestering action.

 A positive displacement pump 

Solution- Pot type feeder


Polyphosphate treatment also exerts a dispersing action on old deposits of iron in tanks and pipes. While this is advantageous to the removal of these deposits, and iron problem may be temporarily intensified, and frequent flushing of pressure tanks and hot water storage tanks may be necessary until the old iron deposits are removed.

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