Oxidation Initiated by Venturi Nozzle
A form of oxidizing agent is through the use a venturi nozzle to add
air (oxygen) to water in order to precipitate and remove iron (Fe) and Manganese
For those that prefer not to add "foreign" chemicals to their water
supply in order to remove iron and manganese the venturi systems fits the bill. This
method is effective for very high levels of iron (Fe) and Manganese (Mn).
Ordinary air is added to the water by a special venturi nozzle. The mixture
of air and water then pass into a detention tank where the oxygen dissolves
into the water. Oxygen is used to oxidize iron, manganese and hydrogen sulphide. Systems will consist of 3 parts: Venturi, air release tank, and
filter tank. An air release valve allows the unused nitrogen and excess air
to bleed off. The water then enters the media filter tank filled with a
media catalyst called "brim", Filter Ag, and Pyrolox. The
media acts as a
catalyst to force the completion of the chemical reaction between the dissolved
oxygen and Fe/Mn so as to form Fe/Mn rust particles. The precipitates are
then physically caught by the catalyst media which is backwashed periodically to
remove the precipitates Chemical rejuvenation of the media is not required.
- No chemicals are added to the water.
- Handles a wide range of Fe/Mn levels.
- Reduces some objectionable odor.
The pH should be over 7.0+ for iron and 8.0+ for manganese. If both Fe/Mn are
substantially present, the pH should be under 8.5 so as to not produce colloidal
Organic material should be less than 5 ppm. Effectiveness of the birm media
will be reduced by long term exposure to chlorine. Manufacturer's
recommend that tannins and hydrogen sulphide should be low.
The precipitate of Fe/Mn tends to lower the pH and thus the alkalinity or pH
adjustment may be needed.
Other manufacturer comments recommend that tannins and hydrogen
sulphide should be low. These other contaminants will produce a precipitate that fouls
the media. Organic material should be less than 5 ppm. Effectiveness of the birm
media will be reduced by long term exposure to chlorine however, short term
chlorination to kill Fe/Mn bacteria is acceptable. No appreciable phosphate
should be present. An "enriched" media is often necessary to
pre-filter, often in the form of bag filtration is often used to remove iron and
manganese which has already oxidized ad it came from the well.