Femen filter bed is a catalytic manganese dioxide based medium, produced in the form granules from natural, high manganese ores rich in manganese oxides. Femen is used as the filtering medium in the treatment of water, especially groundwater, to remove the manganese and iron compounds. With its oxidizing properties, in the presence of oxygen contained in the water, it dissolves manganese compounds into manganese dioxide that is sparingly soluble. Experiments conducted by Firma Bartosz showed high efficiency of Femen filtering medium in the treatment of ground water.
Conditions of use:
- pH of the water of at least 7.0
- speed of filtration up to 15.0 m/h
- minimum thickness of the filter layer in multi-layer filters of 0.3 m
- minimum thickness of the filter layer in single-layer filters of 0.7 m
Method of application:
- as one of the layers in multi-layer filters,
- as a filtering layer in single-layer filters,
- in pressure and open-type filters,
- appropriate aeration of water before filtration is required,
- water rinsing and air sweeping,
- intensity of air sweeping: 75 m3/h x m2 of the filter,
- intensity of water rinsing: 40 m3/h x m2 of the filter/h.
Recommended water for rinsing: treated or with a small content of iron and manganese.
In the case of single-stage filtration, designed to remove iron and manganese, Femen may remove manganese, which is then stored at the bottom layer of the multi-layer filter. At high level of iron in the water, quartz sand can be used in the multi-layer filtering bed to remove iron in the bottom layer of the filter. In the case of double-stage filtration, it can be used in the second stage of filtration as a single-later bed or as a bottom layer in the multi-layer bed. With the appropriate content of manganese dioxide and use, it removes ammonia. The medium can be used in different types of filters. It is particularly useful as a filtering medium for BART filters, which allow using high beds without limitations. It is recommended to conduct technological research in order to verify the effectiveness of treatment for the given case.
The life of Femen filter medium is unlimited, as it corresponds to the life of other natural deposits, provided that it is used and rinsed appropriately.