Iron and manganese are commonly found in groundwater sources. The limits for iron and manganese are 0.3 milligrams per liter (mg / lt) and 0.05 mg / lt, respectively. Exceeding the maximum levels can cause problems such as reddish water, staining with sinks, and damage to pipes. There are different treatments for iron among which we can mention the green sand filters and the Pyrolox and Filox filters.
Birm is an effective and inexpensive means of reducing dissolved iron and crude manganese compounds in water. It can be used under gravity or in pressurized water systems. Birm acts as a catalyst to enhance the reaction between dissolved oxygen (DO) and iron. This reaction produces ferric hydroxide which precipitates and can be easily filtered. Birm's physical characteristics provide an excellent filter media, easy to clean and backwash to remove precipitation.
Birm does not have excessive wear with every backwash and therefore offers a good economic advantage over many other iron removal methods. Other advantages of the Birm; In addition to its low wear and tear and long life, it is efficient at high temperatures, and low maintenance cost since it does not require chemical products for its regeneration, only periodic backwashing is mandatory. When Birm is used for iron removal, it is necessary that the water does not contain oil or hydrogen sulfide, the organic matter does not exceed 4-5 ppm, the dissolved oxygen equal to or less than 15% of the iron content with a pH of 6.8 or more.
If the water influent has a pH lower than 6.8, you can use media such as Clack Corosex, Calcite or soda ash, these before going through the Birm bed. A water with low dissolved oxygen can be raised by aeration. Chlorine disinfection greatly reduces Birm activity. High concentrations of chlorine compounds deplete the catalytic coating.
Clack Birm can also be used for manganese reduction with the same reliability as for iron removal. In these, the application of the water to be treated must have a pH of 8.0-9.0 for best results. If the water also contains iron, the pH should be less than 8.5. High pH can cause colloidal iron in the formulation that is very difficult to filter. All other conditions remain the same, whether for manganese or iron.