Filter Element For Iron And Manganese Removal In Circulating Water
The iron removal process of manganese sand filter material
Natural manganese sand mainly adopts contact oxidation, catalytic process, and wedge wire screen filter element, which is mainly suitable for the process of iron removal in groundwater with iron content less than 20mg / L.
The high valence manganese contained in natural manganese sand can oxidize ferrous iron to trivalent iron in water, and form an active filter membrane with a catalytic effect on the surface, which further improves the iron removal effect.
After aeration, the whole process of iron removal can be completed only by once filtration of natural manganese sand.
Working principle of iron removal by manganese sand filter material
Natural manganese sand filter material has the characteristics of dense grain, high hardness, corrosion resistance, less loss, long service life, insoluble in water, and no increase of manganese content in filtered water. Therefore, natural manganese sand is the most difficult purification agent to dissolve in water. Johnson wedge wire screen filter is the best solution.
Principle of removing iron from manganese sand: the main component of natural manganese sand is manganese dioxide (MnO2), which is a good catalyst for the oxidation of ferrous iron to ferric iron.
The content of MnO2 in natural manganese sand is relatively high, and its iron removal effect is ideal. If the pH value of groundwater containing iron is higher than 5.5, Fe2 + can be oxidized to Fe3 + by contacting with natural manganese sand. The reaction is as follows:
4MnO3+3O2=2Mn2O7 a Mn2O7+6Fe2+3H2O=2MnO2+6Fe3+60H.
The resulting Fe3 + is immediately hydrolyzed into flocculent iron hydride precipitate, Fe3 + 30h = Fe (OH) 3 ↓ C Fe (OH) 3 precipitate is removed by the manganese sand filter layer.
Therefore, manganese sand plays a double role in catalysis and filtration.
The mechanism of iron removal by manganese sand depends not only on its own catalysis but also on the formation of a layer of iron membrane on the surface of manganese sand filter material as an active filter membrane when passing through the wedge-shaped wire screen filtration system.