Fe and Mn can be removed from ground water by using KMnO4 treatment process followed by filtration. this process can be performed at pH 7.0

Amongst several methods to eliminate manganese, biological oxidation seems to be the most appropriate to this occasional pollution problem. Indeed, if filters are continually contaminated by manganese, the bacteria are likely to oxidize the divalent manganese, resulting in an immediate ceasing of the pollution, without human intervention.

As with iron, many bacteria allow, in an aerobic environment, the biological oxidation of manganese by oxygen.

For some bacteria, the oxidation of Mn2 + is indirect: it is due to an increase in pH associated with the growth of these bacteria, which allows the oxidation of Mn2 + by oxygen at an appreciable rate. For other bacteria, it is caused by the action of an intracellular enzyme. For others, dissolved manganese begins by adsorbing to the surface of the cell membrane. It is then oxidized enzymatically. The manganese then concentrates in a sheath surrounding the cell or a group of cells.

Advantages of the process:

In this process, there are no reagents in normal operation. However, it may be useful to use an oxidizer, usually potassium permanganate, during the start-up period.

Contact time is short on most waters. This is the time required for the redox potential to rise. The aeration can be carried out in line (under pressure) or by cascade (gravity).

The solidity of the biological flock makes it possible, as for biological iron removal, to adopt high filtration speeds, which can go, in certain cases, up to 30-40 m · h – 1, on filter materials of which the effective size is higher (1.35 mm) than in the case of physicochemical manganese removal.

The retention capacity is 5 to 10 times higher than in physicochemical mode.

Regards

Iron and Manganese is removed in three steps i.e precipitation, flocculation, sedimentation and

filtration steps. In aerobic environments, the iron and manganese can be oxidized to insoluble forms of

Fe(III) an Mn(IV) compounds. Precipitated solids can be filtered out The simulated groundwater containing iron and manganese is removed by adding ferrous sulfate heptahydrate (FeSO4.7H2O) and manganese sulfate mono-hydrate (MnSO4.H2O) to tap water. Potassium permanganate (KMnO4) with 99.90% purity and aluminum sulphate hexadecahydrate

Al2(SO4)316H2O) were used as sources of Potassium permanganate and alum. Sodium hydroxide (NaOH) was used to adjust pH.

See the following link for details.

https://www.google.com.pk/url?sa=t&source=web&rct=j&url=https://www.mdpi.com/2073-4441/9/7/498/pdf&ved=2ahUKEwjNj9v1x6fyAhXSxIUKHbh2CgAQFnoECDYQAQ&usg=AOvVaw3Ke8PwtMkoknkuJbdc6HA1

https://www.google.com.pk/url?sa=t&source=web&rct=j&url=https://www.matec-conferences.org/articles/matecconf/pdf/2018/21/matecconf_bcee32018_05018.pdf&ved=2ahUKEwjNj9v1x6fyAhXSxIUKHbh2CgAQFnoECCcQBg&usg=AOvVaw3kjiMCma2yoou3W2dgOeW-