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cferiante

Lesson Three: Ammonia and Chloramine - Safe Drinking Water Foundation - 0 views

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    DRIVER-TREATMENT-WATER-INFRASTRUCTURE-CHEMISTRY-CHLORAMINE One new option that communities with ammonia problems have is biological filtration. This is a safe, chemical-free, method of removing ammonia. In a biological filtration facility, one of the stages of filtration is to pass the water through a special filter that is full of nitrifying bacteria. These bacteria take in the ammonia and some oxygen and perform a bio-oxidation reaction. They oxidize the ammonia into nitrite NH3 + O2 -> NO2- + 3H+ Then further oxidize that into nitrate, NO2- + H2O -> NO3- + 2H+. The bacteria gain energy from these reactions and are specialized to do them very efficiently. This process is part of the natural nitrogen cycle and does not produce any harmful byproducts. The nitrate that is produced by this process can easily be removed from the water by the reverse osmosis membrane in the final stage of the filtration process. The reaction between chlorine and ammonia can be written as NH3 +HOCl -> NH2Cl + H2O. In this chemical equation, NH3 is ammonia and HOCl is hypochlorous acid which is formed when the chlorine is first dissolved in the water. The primary result of this chemical reaction is NH2Cl, a chemical known as chloramine. Chloramine is a disinfectant like chlorine, it is a weaker disinfectant than chlorine but it lasts much longer in water. The chlorine concentration in water can gradually decrease as the chlorine evaporates out but chloramine does not do this. This makes it useful for making sure water stays disinfected throughout drinking water distribution systems. In areas where there is no, or very little, ammonia in the raw water treatment facilities might still want to use chloramine for this purpose. After chlorinating (disinfecting) the water, as the last step in the treatment process, they add ammonia and more chlorine to the water so that they react and create chloramine.
cferiante

Ozone Water Treatment for Well Water: The 6 Things You Need to Know - 0 views

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    DRIVER-WATER TREATMENT TECHNOLOGY Ozone water treatment oxidizes iron, manganese, and sulfur in your well water to form insoluble metal oxides or elemental sulfur. These insoluble particles such as rust, are then removed by filtration which is typically activated carbon, manganese dioxide, or other media such as filter sand. Ozone is much faster at killing bacteria and oxidizing iron and manganese compared to chlorine or peroxide. One advantage for home use is that ozone is quite unstable and will degrade over a time frame ranging from a few seconds to 30 minutes.
ingridfurtado

Corrosion Rate | American Galvanizers Association - 0 views

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    "Approximately 85% of all steel produced is carbon steel and therefore susceptible to natural oxidation and galvanic corrosion. The rate of corrosion is well understood in typical atmospheric conditions, but for the design engineer, the precise localized or micro-environment conditions must be well understood for him/her to have confidence in the ultimate durability of the design. Other micro-environments include exposure to fresh and salt water (in or very near) or in soil. "
ingridfurtado

Corrosion Basics: Corrosion and the Environment - 0 views

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    "Formation of a surface layer, whether it is based on an oxide, carbonate, sulfate, or any other compound, is a major factor in corrosion resistance, particularly if the layer effectively isolates the metal substratum from the environment. Such a naturally formed coating must be diffusion- and moisture-resistant to be effective. Ordinary iron does not naturally form an effective barrier; its rust permits oxygen and moisture to penetrate and continue rusting. Thus, unless precautions are taken, such as applying a protective coating over the surface, failure will eventually occur."
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