Are you worried about manganese quantity in your water and would like to learn how to remove it? Luckily, several water treatment methods can effectively eliminate manganese from water.
Below is a step-by-step process on how to remove manganese from water.
An ideal way to identify the source of manganese in your water is to investigate the water source.
The primary source of water with manganese is wells. Manganese exists naturally in soils, rocks, and sediments. When it rains, water washes manganese from the surface and trickles into the wells.
Rainwater also seeps through the soils that contain this metal, picks it up, and deposits it in the well water.
In the case of deep wells, the manganese level in water might be higher since the water is in prolonged contact with contaminated rocks and sediments.
When manganese comes into contact with well water, it dissolves and might have a purple, blackish or dark brown color.
Manganese in your water can result from human activities such as mining and traffic emissions.
If your water source is near a city with heavy traffic or near a coal-mining area, the soil around might have manganese. When it rains, this metal can find its way into the water source.
Before answering how to remove manganese from water, you need to test its level in your water.
You can quickly identify manganese in water by detecting the bitter, metallic taste in your drinking water. If your water has higher levels of manganese, you will notice staining on your home appliances.
A well water test kit can also indicate the presence of manganese in your water.
Take your water sample and dip a test strip when testing at home. Leave it submerged for a few seconds before removing it. If the strip changes color, your water contains manganese.
The only downside is that these DIY testing methods won’t tell you the level of manganese in the water.
The most effective method for identifying the level of manganese in water is laboratory testing. Be sure to use an accredited laboratory for extensive and reliable tests.
Collect a sample of your water from the entry point and send it off to the lab. Testing water in the laboratory will help you know the exact metal in your water and its levels.
The lab will also inform you if your water has other impurities such as iron, sulfur, or chloride.
After identifying the level of manganese in your water, you can know whether your water poses health risks or not.
If manganese in your water occurs in quantities greater than 0.05mg/L, it might take a toll on your clothes and home appliances. The water might have a bitter, metallic taste and smell and cause various health issues if consumed over time.
Wondering how to remove manganese from water effectively? Unlike chlorine, manganese is a fairly tricky impurity to remove from water.
The effectiveness of your treatment method will depend on the level and the type of manganese in your water.
The two common types of manganese are manganous manganese and manganic manganese. Manganous manganese exists in the dissolved form, while manganic manganese exists in the solid state.
Once you’ve determined the kind of metal in your water, you can remove it using water treatment methods such as:
A water softener is an effective tool for treating hard water but can also work best to remove small amounts of manganese.
The softener uses ion exchanges to substitute manganese with sodium. The process involves releasing sodium into the water that imparts manganese molecules with a charge. As a result, manganese molecules stick to the resin.
When the resin is at capacity, the water softener backwashes its tank and flushes all the manganese out.
For the water softener to remove manganese in water, certain conditions need to be in place:
- The manganese must be in the unprecipitated state (fully dissolved)
- The water must have a pH of more than 6.7
- Your water should have a low amount of dissolved oxygen
- The dissolved iron concentration should not exceed 5 mg/L
- Total dissolved solids in your water should be low
Manganese in its precipitated form and high amount of dissolved oxygen in your water can cause severe damage to the resin. Ensure that your water does not come into contact with potent oxidizing agents such as chlorine or potassium permanganate.
Oxidized manganese and iron in your water will precipitate to a physical form that your water softener can’t handle. Eventually, precipitated manganese will damage your water softener resin.
Dissolved ion concentration that exceeds 5 mg/L can reduce the effectiveness of your water softener at removing manganese.
If the total dissolved solids in your water are high, other minerals will compete with manganese for space on your water softener resin. These minerals might displace manganese attached to the resin and return it to the water.
Oxidation filtration involves injecting oxygen into the water to eliminate impurities. It is an effective method used to remove ions in water.
Manganese usually exists in its unprecipitated state in water. To remove it, you should convert it into its precipitated form.
The easiest way to change unprecipitated manganese into its precipitated state is to pretreat it with a strong oxidizing agent.
You can use compressed air, chlorine, or potassium permanganate to oxidize your water. These strong oxidizers will precipitate manganese. Then, water is passed through a filtration medium.
Use an iron medium like Filox to remove the precipitated manganese with aeration. For chlorination, the best filtration medium to use is catalytic carbon. The good thing about catalytic carbon is that it removes chlorine and manganese.
If you’re using potassium permanganate, you need to have a filter that uses greensand as a medium. Greensand filters will remove manganese and odors from your water.
Reverse osmosis (RO) is a reliable water treatment method that removes most contaminants in water. It is also one of the best treatment options for removing manganese from water.
Reverse osmosis uses a semi-permeable membrane that has tiny pores for sieving water. Water is pushed against the semi-permeable membrane for filtration.
The membrane can only allow small water particles to pass through, leaving manganese and other contaminants behind. These contaminants are later flushed away with wastewater.
The reverse osmosis filtration system is ideal for removing dissolved manganese even in its highest concentration.
You don’t need to backwash your system, unlike other filtration methods. You only need to replace the filter membranes every six months and change the semi-permeable membrane after every two years.
You can install a reverse osmosis unit at the entry point of water and ensure your water has relatively high pressure. The pressure will push water against the membrane. Use a pressure pump to make the system effective.
If handled the right way, any treatment method above should remove manganese from your water. But before using the water for drinking, testing it again can be a great idea. You don’t want to use water that will take a heavy toll on your health and home appliances.
You can use observational self-testing as your first method of testing manganese in treated water. This method involves simple observation to determine if there’s any color, smell, or taste in your water.
If the water has visible dark brown, purple or black color, metallic taste, and sulfur-like smell, your water could have manganese molecules. That means your water treatment option was not effective.
If your water is clear and odorless after treatment, you might want to ensure no manganese molecules are left. The most effective method of testing manganese at home is using a well water test kit.
Observe any color change in your test strip after dipping it in your treated water. If the test strips change color, your treatment method didn’t remove all manganese in the water.
Repeat the treatment method and observe all conditions to ensure an effective treatment option. Alternatively, use a different water treatment method or hire a water professional to test your water and recommend the best treatment option.
Below are frequently asked questions on manganese removal from water.
Well water collects manganese that exists naturally in soils and rocks. Rainwater can also collect manganese on the surface and deposit it in wells or rivers.
In addition, human activities such as industrial discharge or mining can also deposit manganese in water sources.
If your water has manganese, it might appear purple, dark brown, or blackish. The water will also stain your home appliances and clothes. Your drinking water might have a bitter, metallic taste or sulfur-like smell.
Drinking manganese contaminated water above acceptable levels for a long time might affect one’s memory, attention, and motor skills. Infants who drink water with high manganese levels might develop behavior and learning problems.
According to the EPA, the acceptable manganese level for drinking water is 0.3mg/L (milligrams per liter), while for aesthetic purposes, the level should be 0.05mg/L and below.
The cost of removing manganese from water varies depending on the water treatment option used. You’ll spend $500 to $2800 to install your water softener or reverse osmosis system at home.
Once installed, you’ll only need to replace the semi-permeable membrane or buy oxidizing agents.
The cheapest way to get rid of manganese from water is by using a water softener. This method involves an ion exchange process by introducing sodium that replaces manganese in the water. As a result, manganese sticks to your resin and is removed during backwashing.
Reverse osmosis is an effective process of removing manganese, among other contaminants. It has a water purification system with several filtration stages that eliminate all contaminates smaller in size than water molecules.