Removal of Iron and Manganese

In water with a high level of carbonate, FeCOj and MnCOj may be precipitated directly by raising the pH above about 11.5 by the addition of sodium carbonate or lime. However, this approach is less popular than oxidation. 

Relatively high levels of insoluble iron(III) and manganese(IV) frequently are found in water as colloidal material, which is difficult to remove. These metals can be associated with humic colloids or peptizing organic material that binds to colloidal metal oxides, stabilizing the colloid. 

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The Relationship Between Manganese and Iron in Sediment Ponds. To under-stand the behavior in and removal of iron and manganese from water, it is important to know the interactions of these two metals. A common occurrence in sediment ponds is the sudden development of a dissolved manganese problem. The cause may be ferrous iron from the incoming water due to the disturbance of a new site. The ferrous iron can react with insoluble manganese oxide (Mn02) in the sediments at the bottom of the pond according to Equations 12.5 and 12.6 ... 

As such, it is used in water treatment to control taste and odors, remove color, and control biological growth. It promotes the removal of iron and manganese species by rendering them insoluble through oxidation ... 

Part III covers the various unit processes employed in water and wastewater treatment including water softening water stabilization coagulation removal of iron and manganese by chemical precipitation removal of nitrogen by nitrihcation-denitrihcation removal of phosphorus by chemical precipitation ion exchange and disinfection. 

Iron and manganese may be removed by reverse osmosis and ion exchange. The unit operation of reverse osmosis was discussed in a previous chapter the unit process of ion exchange is discussed in a later chapter. This chapter discusses the removal of iron and manganese by the unit process of chemical precipitation. 

Van Beek, C. G. E. M., 1980, A model forthe induced removal of iron and manganese from groundwater in the aquifer in 3rd Water-Rock Interaction Symposium, Edmonton,... 

Removal of iron and manganese from water involves both oxidation and precipitation, and is thus, a typical example of chemical oxidation precipitation. 

For the removal of iron and manganese from water, the low solubility of hydroxides of the higher oxidation states of these metals is employed. 

The technique for the removal of iron and manganese during water treatment employs the oxidation of bivalent well-soluble forms to multivalent low-soluble hydrated oxides, which can be removed from water either by sedimentation or filtration. Oxidizing agents in this case are atmospheric oxygen, chlorine, potassium permanganate, ozone and chlorine dioxide. 

Perron J. and D. Turner, Purification of Cobalt-Containing Ore-Leaching Solution by Removal of Iron and Manganese with Oxidation by the 02-S02 Gas Mixture , WO Patent 2000056943, 2000... 

Groundwater is typically not turbid (cloudy), so it does not require the type of treatment used for surface water. At minimum, it requires disinfection. Removal of iron and manganese by aeration may be needed, and if the water is very hard, it may be softened by ion exchange. 

This can be colored, as turbid surface water may contain humus as well as iron and manganese, either in the oxidized form or bound to organic matter. Water of this type is treated by aeration + coagulation + addition of alkali + clarification + sand filtration. The removal of color and organic compounds usually requires a method based on chemical precipitation. Some reduction in organic matter content, of course, can be achieved by simple filtration. The removal of iron and manganese, on the other hand, usually requires ... 

In large applications, automatic gravity Alters are often nsed for the treatment of mains or groundwater, including aeration, removal of iron and manganese, and deacidiflcation. 

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