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De-ferrisation and manganese removal from water

In groundwater, iron naturally occurs in dissolved state in the bivalent form as Fe2 + and Fe (OH) +. The trivalent form occurs in water in the colloidal form as iron (III) -hydroxide.

The removal of iron from water, de-ferrisation, usually occurs through aeration and filtration. Other oxidation methods such as the use of active chlorine are also possible, but due to the large amounts needed for this it is expensive. The formed Fe (OH) 3 can be collected and removed as a brown precipitate in a sand filter.

For a proper process of iron oxidation the right pH is required. The de-ferrisation process is accelerated (catalyzed) by the presence of already formed iron hydroxide present on the sand filter. Therefore, it is important to take into account when starting a filter process that the removal of iron does not always starts immediately and completely and needs some time. This is called the filtration start-up time of a filter.

If manganese is present in the water, this will only be removed after almost all of the iron has been removed. The manganese removal process is complex and proceeds through the formation of Mn3O4 (as catalyst) to MnO2. By adding a manganese oxide, the process can be accelerated or improved, but this  will not always have a long-term effect.

Please keep in mind that the presence of Methane and Ammonium in groundwater has a disturbing effect. This problem can however be solved.

During excavation and construction works it is possible that well water has to be removed.. This groundwater often contains iron and manganese and is often discharged to surface water. The iron and manganese must be removed first in order to comply with the disposal requirements. There are also mobile water purifiers for rent at Logisticon Mobile Water Rental solutions.

For optimization or improvement of your own de-ferrisation or manganese removal please feel free to contact one of our specialists.