Some recent studies have been conducted to look at the effectiveness of a variety of methods to remove iron and manganese from well water. These two contaminants are only harmful to health in large concentrations, but they can affect the taste and appearance of well water and cause laundry stains. One of the most thorough studies on this subject was carried out by a University of Pittsburgh graduate student. The study was intended to figure out the ideal treatment method to remove the most substantial amount of manganese while leaving behind the smallest amount of disinfectant byproduct. Let’s take a closer look at the findings that should be interesting for well water users.
Conducting the Study
Three different chemicals were used in the study; they are chlorine, chlorine dioxide and hydrogen peroxide. Removing iron and manganese requires that their ions are broken down. This requires an appropriate injectant and the substance that gets the extra electrons is known as the oxidizing agent. In order to be deemed an effective oxidizing agent, the chemical would have to break down ions at different pH levels.
The Oxidizing Agent
This study discovered that hydrogen peroxide tested with a variety of pH levels wasn’t an effective oxidizing agent for removing manganese. Iron was a different story; hydrogen peroxide was an adequate oxidizing agent in this case. So, there was no particular benefit to be gained by using hydrogen peroxide. The peroxide would not oxidize the manganese, and it even created complications with the chlorine that was needed for disinfection. The manganese removal varied a great deal depending on the different injectants used. Another interesting discovery was that it takes more than 100 minutes to perfectly oxidize manganese with chlorine.
Combining Chlorine with Media Iron Filtration
When chlorine is combined with filtration media that is specifically designed to remove iron, the manganese can also be removed. This happens because of a catalytic reaction that occurs between the chlorine used for disinfection and the filter media. This causes the manganese to become instantly oxidized across the surface of the iron filtration media. Then, a strong backwash of around 10 gpm can be used to flush away the accumulated manganese oxide deposits. So, by pairing together a chlorine feed and a good iron filter, manganese can be removed effectively.
Using Less Chemicals
Any water treatment method that can be used without adding extra chemicals is ultimately a good thing. After all, one of the goals of water treatment is to provide clean water that’s safe and pleasant to use for activities, such as drinking, cooking, bathing, and cleaning. This often involves taking steps to remove as many chemicals and associated byproducts as possible. We have become accustomed to chlorine being used as a disinfectant, but many people dislike the “swimming pool” odor and taste. Of course, chlorine can be easily removed with an appropriate water filtration system to provide a more palatable water supply for drinking and cooking.