Manganese is a widely occurring mineral substance with a key role to play in human nutrition. Yet manganese can also present a problem if found in well water in quantities greater than 0.05 mg/L. In that case, manganese can give the water an unsightly brown appearance, while also often lending the water an unappealingly bitter taste.
Manganese may also cause films on the surface of toilet water, as well as pellet-like debris inside of your dishwasher. If you believe that your residential well system may suffer from elevated manganese levels, keep reading. This article takes a closer look at three effective strategies a well contractor can use to remove manganese from your water supply.
1. Water Softener
Manganese may exist in one of two states: unprecipitated or precipitated. Unprecipitated manganese has essentially fully dissolved into the water, making detecting the manganese hard aside from the characteristic brown color. If present in high enough quantities or subject to certain chemical conditions, manganese may precipitate into the physical form of small bits of dark debris.
Although generally used to remove minerals such as calcium and magnesium, water softeners also demonstrate a strong ability to remove manganese in its unprecipitated form. Water softeners work by means of ion exchange, imparting the manganese molecules with a charge that causes them to cling tightly to resin beads in the softener.
Water softeners offer effective results, but only under ideal conditions. Problems may ensue if any precipitated manganese happens to be present. Manganese in this form can cause serious harm to the resin beads used to accomplish the ion exchange. Likewise, the water must have a pH value greater than 6.7, because otherwise the manganese may precipitate and create problems.
Likewise, the presence of iron in the water can reduce the effectiveness of water softeners at removing manganese. If dissolved iron concentrations exceed 5 mg/L, then a water softener may not yield effective results.
2. Filtration System
As noted above, a water softener cannot remove manganese that exists in a precipitated state. Instead, a well contractor must employ some form of physical filtration. Simple cartridge filters offer perfectly adequate and effective results. These filters use fine mesh screens to physically intercept manganese and other small pieces of debris present in the water stream.
Be aware that physical filters will cease to deliver effective results once they have reached their maximum capacity. For that reason, you must have a well technician regularly inspect your filter. You should often clean a clogged filter to restore proper functionality. A well technician may need to replace other types of filters entirely once they reach capacity.
Manganese rarely exists entirely in its precipitated state. In other words, a certain proportion of the manganese remains in its unprecipitated state. In order to remove this manganese, it must first be coaxed into its precipitated form. The easiest way to do this involves pretreating the water with oxidizing agents.
A professional may employ a variety of different oxidizing agents to precipitate manganese. The most basic method involves venting air into the well water. As air bubbles move through the water, the oxygen reacts with the manganese, causing it to fall out into its physical form.
Chlorine offers even more potent oxidizing results. That said, the chlorine must remain suspended in the water for a longer period in order to achieve complete precipitation. A well professional may add chlorine to the well itself or integrate the chlorine into the water lines used to supply the pump and/or pressure tank with water.
Manganese in your well water can be a real nuisance and may even pose health risks if present at high enough concentrations. Fortunately, many ways exist to remove manganese from your water supply. For information about the best manganese removal method for your well water, please contact the experts at Brown & Cox.