Clack Birm Filtration Media
light-weight media for the removal of iron
Birm® is a relatively light-weight and economical media for the reduction of dissolved iron. Like most iron removal medias, Birm® acts as an insoluble catalyst to enhance the reaction between dissolved oxygen and the iron compounds to form ferric hydroxide which is then removed through mechanical filtration in the media bed. As a catalyst, Birm® is not consumed in the iron removal process and it does not need to be regenerated. Over time, mechanical wear and fouling by other contaminants will reduce Birm®’s effectiveness and it will need to be replaced.
- economical price – cheaper than most other iron removal medias
- light weight (under 40 lbs per cubic foot) allows for less frequent backwash and lower backwash flow rate
- no regeneration required
While popular due to its economical price and light weight, Birm® is not ideal for all iron treatment applications. It has specific operating conditions that must be met for successful treatment. While in the right conditions, Birm® can be successfully used to remove manganese as well as iron, it is our opinion that other media options generally have better manganese performance characteristics. If used for manganese reduction, the pH of the raw water should be between 8.0 and 8.5 if you are also attempting to treat iron, or 8.0 and 9.0 if treating only manganese. pH greater than 8.5 could cause formation of colloidal iron which is very hard to filter.
Other important considerations when using Birm® media:
- Manufacturer recommended service flow rates are much lower than other iron removal flow rates – locally favorable operating conditions may allow higher flow rates
- pH must be at least 6.8
- Birm® should not be used if organic matter exceeds 4 ppm, or if oil or hydrogen sulfide (rotten egg odor) are present
- If the dissolved oxygen content is not at least 15% of the iron level (and 29% of manganese content), pre-aeration is required (we recommend pre-aeration with all Birm® filters)
- Free chlorine levels above 0.5 ppm may greatly reduce Birm®’s effectiveness and may damage the media, reducing its service life
- Alkalinity should be 2 times the combined sulfate and chloride concentration
- Do not pre-treat with polyphosphates
- NOT FOR INSTALLATION IN CALIFORNIA