IRON AND MANGANESE REMOVAL
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IRON REMOVAL (with Katalox-Light®)
Iron is a common water contaminant. It can be difficult to remove because it may change its valence state that is change from the water soluble ferrous state (Fe2+) to the insoluble Ferric state (Fe3+). When Oxygen or an oxidizing agent is introduced, ferrous states changes to ferric which is insoluble and it precipitates, leading to a rusty (red-brown) appearance in water. This change can occur when deep well water is pumped into a distribution system where it adsorbs oxygen. Ferric iron has to be removed before it destroys valves, piping all other water treatment equipments and water-using devices. Katalox-Light® provides a large filtration area and high catalyst to speed up the process. Chemical OxidationThe atmospheric oxygen which is introduced into water during aeration is usually effective in the oxidation of Iron (II). However, when the iron is organically complexed , aeration alone is not sufficient. Secondly, IRON OXIDATION is very slow at pH <7.0. Alternative Oxidants like OXYDES, Chlorine or Hydrogen Peroxide could be employed for Iron Oxidation when aeration is not satisfactory. Chemical oxidation is frequently applied when Iron and Manganese are to be removed simultaneously in a single filtration step and Manganese Oxygenation is very slow at pH <9.5; The Oxidation of IRON (II) by different oxidants can be described by the following chemical reactions: 1.OXYDES (solid state H2O2):
2Fe2+ + H2O2 + 4H2O →2Fe(OH)3 + 4H+ 2.Chlorine:
2Fe2+ + Cl2 + H2O → 2Fe(OH)3 + 2Cl- + 6H+ 3.Hydrogen peroxide:
2Fe2+ + H2O2 + 4H2O → 2Fe(OH)3 + 4H+ |
MANGANESE REMOVAL (with Katalox-Light®)
If Manganese is not removed it can lead to health problems, staining or discolored water in the distribution systems. The removal of dissolved manganese from water requires a strong catalyst such as Katalox-Light® to handle pH and an oxidant such as OXYDES, Chlorine or Hydrogen peroxide. Manganese precipitates out faster with higher pH-values and greater concentration of oxidant. The reaction with Katalox-Light: 2CO2 + Ca(OH)2 = Ca(HCO3)2 Mn(HCO3)2 + O + Ca(OH)2 = MnO2 + Ca(HCO3)2 + H2O Waters containing carbonate hardness and a little free Carbon dioxide (CO2) have a pH of about 7.5 to 8.5 or over. Fast reaction with Katalox-Light®Mn(II) + MnO2 (Katalox-Light) Mn (II) MnO2 Because of its adsorptive properties, Katalox-Light® (MnO2) accelerates the removal of Mn(II) form solution and causes the mixed oxide to form. It is the presence of this manganese dioxide ratio on the ZEOSORB filter media that makes the removal of Mn(II) during oxide coated media filtration so effective. It makes it the most effective media available in the water treatment industry. Another benefit to use Katalox-Light® media is that comparatively higher filtration rates are possible with the application to remove iron and manganese as it raises pH. The increased pH rate can increase higher filtration rate, reduced filter size and construction costs. With Katalox- Light ® Filtration velovity of 10 - 12 gpm/ft2 ( 24 – 30 m/h) can be achieved.
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