Birm Iron Filter Media

In ground water dissolved iron is usually in the ferrous bicarbonate state.  This is due to the excess of free carbon dioxide, and the iron is not filterable. By acting as a catalyst between oxygen and soluble iron compounds, Birm filter media enhances the oxidation reaction of Fe++ to Fe+++.  This produces ferric hydroxide which precipitates and may be easily filtered.

The physical characteristics of Birm provide an excellent filter media which is easily cleaned by backwashing to remove the precipitant. Birm is not consumed in the iron removal operation.  It offers a tremendous economic advantage over many other iron removal methods.

Other advantages of Birm include:

• Long material life with relatively low attrition loss
• Wide temperature performance range and extremely high removal efficiency
• Negligible labor costs
• Does not require chemicals for regeneration, only periodic backwashing

When using Birm for iron removal, it is necessary that the water contain no oil or hydrogen sulfide. Organic matter can not exceed 4-5 ppm. Lastly, the Dissolved Oxygen (D.O.) content must be equal to at least 15% of the iron content with a pH of 6.8 or more.

If the influent water has a pH of less that 6.8, neutralizing additives such as Corosex®, Calcite or soda ash may be used prior to the Birm filter to raise the pH. A water having a low D.O. level may be pretreated by aeration.

Birm Specifications

• Color: Black
• Bulk Density: 36-38 lbs./cu. ft.
• Mesh Size: 12 x 50
• Temperature Range: 35-100oF
• pH range: 6.8-9.0
• Dissolved Oxygen (D.O.) content must be equal to at least 15% of the iron and 29% of the manganese content
• Bed depth: 30-36 in
• Backwash rate: 10-12 gpm/sq. ft.
• Service flow rate: 3.5-5 gpm/sq. ft

Birm Iron Filter Media Examples