Manganese Dioxide is a high rate, granular whole house water filter media used for removing Hydrogen Sulfide, Iron and Manganese compounds from water supplies. The media operates both as a classical filter working with an oxidant and as a catalytic media due to its ability to accelerate the reaction between the oxidizing agent and any prevalent dissolved Oxygen with Sulfide, Iron and Manganese present.
Dissolved iron, Manganese and Hydrogen Sulfide will stay in solution unless the equilibrium is changed. Iron and Manganese that is not oxidized become catalytically precipitated and then adsorbed directly on the media. The media is a very dense media that stops oxidized (precipitated) forms of Iron, Manganese and Hydrogen Sulfide from passing through the bed. Most of the Manganese is rapidly removed in the first few inches of the media where it is further oxidized to Manganese Dioxide. The adsorbed Manganese, Iron and precipitated Sulfur are expelled during backwash. Any insoluble ferric hydroxide particulate growths are also expelled during backwash.
The media must be properly backwashed to break loose and remove the filtered contaminants and precipitated Iron, Manganese and Hydrogen Sulfide. (Every day is typical). System sizing of the control valve and tank are necessary to sustain media performance. A continuous reaction occurs with the addition of an oxidant, regenerating the media surface and replenishing the media. For difficult applications, Manganese Dioxide filters can be enhanced with aeration, chlorination, and ozone. Manganese Dioxide filters are recommended before softeners to protect the ion exchange resin from fouling.
Advantages
- Efficient reduction of manganese, iron and hydrogen sulfide
- Long service life
- Only regular backwashing is necessary
- Ability to process high flow rates with low pressure drop
- Continuous regeneration
- Ability to be utilized with common oxidants including Chorine, Sodium Hypochlorite & Potassium Permanganate
- 10 – 30 second reaction time with oxidant additive
- Converts ferrous iron to ferric iron
- Converts H2S to Sulfur
- Converts Manganese to MnO2
- No chemical regeneration is required but may reduce service life
- NSF/ANSI Standard 61-2002 Certified
Requirements
- Service flow rate – 6 GPM / cu ft.
- Backwash flow rate – 12 – 15 GPM per square feet of media
- Bed depth – 20” minimum
- Freeboard – 30% – 50%
- pH range – 6.0 – 9.0
Applications:
- Removal of Iron up to 27 ppm
- Removal of Manganese up to 11 ppm
- Removal of Hydrogen Sulfide (rotten egg smell) up to 17 ppm
Note:
Not recommended for Iron Bacteria and Manganese bacteria removal. Not recommended for tannin and organics.
ORP requirements
Manganese Dioxide acts as a catalyst to use the Oxygen content of the water for oxidation. Using an ORP Meter, any reading above a negative 170 millivolts indicates Manganese Dioxide can be used effectively without the use of additional oxidants. Any reading below indicates oxidants will be required.