Clack Birm Filtration Media

Birm® is an efficient and economical media for the reduction of dissolved iron and manganese compounds from raw water supplies. It may be used in either gravity fed or pressurized water treatment systems. Birm acts as an insoluble catalyst to enhance the reaction between dissolved oxygen (D.O.) and the iron compounds. In ground waters the dissolved iron is usually in the ferrous bicarbonate state due to the excess of free carbon dioxide and is not filterable. Birm, acting as a catalyst between the oxygen and the soluble iron compounds, enhances the oxidation reaction of Fe++ to Fe+++ and produces ferric hydroxide which precipitates and may be easily filtered.

ADVANTAGES

• Under the proper conditions, no chemicals to purchase for maintenance. Regeneration not required.

• Iron removal efficiency is extremely high.

• Negligible labor cost: only periodic backwashing required.

• Durable material with a long life and wide temperature range.

• Weighs only 35-40 lbs./cu. ft.

PHYSICAL PROPERTIES

• Color: Black

• Bulk Density: 35-40 lbs./cu. ft.

• Mesh Size: 12 x 50

• Specific Gravity: 2.0 gm/cc

• Effective Size: 0.48 mm

• Uniformity Coefficient: 2.7

CONDITIONS FOR OPERATION

• Alkalinity should be greater than two times the combined sulfate and

chloride concentration.

• Maximum water temp: 100oF/38oC

• Water 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.

• Freeboard: 50% of bed depth (min.)

• Backwash rate: 10-12 gpm/sq. ft.

• Backwash Bed Expansion: 20-40% of bed depth (min.)

• Service flow rate: 3.5-5 gpm/sq. ft. intermittent flow rates and/or favorable local conditions may allow higher flow rates