Are you worried about manganese in your water and would you like to learn how to remove it? As excess manganese can have negative effects on your health, it’s something that you should definitely consider.
So, how is manganese removed from water? The easiest and most effective way to remove manganese from drinking water is through either Air Injection Oxidation, Reverse Osmosis Filtration or Ion Exchange (Water Softener).
To remove manganese via Air injection oxidation, you’ll need to get a whole house filtration system with NSF certification for iron and manganese removal. The best air injection oxidation system is currently the Springwell Iron & Manganese Filter.
To remove manganese via Reverse osmosis, you’ll need to get an RO system with NSF certification for manganese removal. We like the Waterdrop G3 800 filter for this purpose, although the Aquatru filter is more portable and equally efficient at removing manganese.
If you want to go the Ion-exchange route to remove manganese, get a salt-based whole house water softener that uses Ion-exchange technology. A good example is the Springwell SS1 Water Softener.
Here’s a step-by-step guide to help you identify and remove the source of manganese in your water
- Identify the source of manganese
- Test manganese levels in your water
- Choose appropriate manganese treatment method
- Re-test your water after treatment
Step 1: Identify the Source of Manganese in Your Water
An ideal way to confirm that manganese is in your water is to investigate your water source, either municipal or well water. The primary source would be wells since they’re more prone to natural contamination than municipal city water. Manganese exists naturally in soils, rocks, and sediments. When it rains, water washes this naturally existing element from the surface into wells.
Rainwater also seeps through 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 it comes into contact with well water, it dissolves and might have a purple, blackish or dark brown color. Other telltale signs include a bitter and metallic taste and staining on home appliances and clothes, even if the water isn’t necessarily colored. That’s how you’ll know for sure that you have manganese in your water source, but if it’s not as apparent, you’ll need to run some tests.
Step 2: Test Manganese Levels in Water
Even before deciding to remove manganese from your water, you’ll need to first test the manganese levels in your water before choosing an appropriate treatment method.
You can do that via a well water test kit. Take your water sample and dip a test strip in it. 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 exact level of contamination. Therefore, you won’t know if it’s above the allowable limits of manganese in water, which is 0.05 mg/L according to the EPA (Environmental Protection Agency) standards.
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 and send it off to the lab. The laboratory will give you a list of all the metals present in the water with their contamination levels.
If manganese in your water is greater than 0.05mg/L, it might have an effect on your clothes and home appliances. The water will have a bitter, metallic taste and smell, and cause various health issues if consumed over time. So, it’s very important to remove it.
Step 3: Choose a Treatment Method to Remove Manganese From Water
Unlike chlorine, manganese is a fairly tricky substance to remove from water. The effectiveness of a treatment method depends on the type of manganese in water. The two common types of manganese are manganous manganese and manganic manganese. Manganous manganese exists in dissolved form, while the manganic version exists in a solid state.
Once you’ve determined the kind of manganese in your water, you can start the process of removal by choosing any of the treatment methods below:
Option 1: Use Air Injection Oxidation to Remove Manganese
Oxidation filtration involves injecting oxygen into the water to eliminate impurities such as iron, arsenic, and manganese. It is an effective method used to remove ions that form manganese in water.
Manganese usually exists in its unprecipitated state in water. Removing manganese via oxidation would convert the manganese into its precipitated form. The easiest way to change unprecipitated manganese into its precipitated state is to pre-treat it with a strong oxidizing agent.
You can use compressed air, chlorine, or potassium permanganate to oxidize water. These strong oxidizers will precipitate manganese. The water is then 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 both chlorine and manganese, so there are no side effects even if you use chlorination to remove 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 its odor) from your water.
What’s the best air injection system for manganese? Springwell Iron & Manganese Filter
Option 2: Use Ion-exchange (Water Softener) to Remove Manganese
Water softener is an effective tool for removing hard water minerals, but it can also remove small amounts of manganese.
To remove manganese, the water softener substitutes manganese ions in water with sodium ions via ion exchange. 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 full capacity, the water softener backwashes its tank and flushes all the manganese out.
For a water softener to remove manganese in water, there are certain conditions that needs 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
- The water should have low amount of dissolved oxygen
- The dissolved iron concentration should not exceed 5 mg/L
- Total dissolved solids (TDS) 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 water softener resin. Ensure that the water doesn’t come into contact with potent oxidizing agents such as chlorine or potassium permanganate. These oxidizing agents are largely removed by RO systems, not water softener.
Oxidized manganese and iron in water will precipitate it 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 also reduce the effectiveness of your water softener. Therefore, it’s important to frequently check the resin.
If the TDS is high, other minerals will compete with manganese for space on the softener resin. These minerals might displace and return manganese attached to the resin into the water.
So, what’s the best water softener for manganese? We recommend the Springwell SS1 Water Softener
Option 3: Use Reverse Osmosis to Remove Manganese
Reverse osmosis (RO) is a reliable water treatment method that removes most contaminants in water. It’s also one of the best treatment options for removing manganese.
RO uses a semipermeable membrane that has tiny pores for sieving water. Water is pushed against the semipermeable 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 via wastewater.
The RO filtration method is ideal for removing dissolved manganese even in its highest concentration. Unlike other methods, you don’t need to backwash your system. You only need to replace the filter membranes every six months and change the semipermeable membrane after every two years.
You can install a RO system at the entry point of water and ensure your water has relatively high pressure. The pressure will push water against the membrane. If your water supply has low pressure, you can use a pressure pump to make the system effective.
Step 4: Re-test Your Water After Treatment
If done correctly, any of the above treatment methods should easily get rid of manganese, but testing the water again is a good idea.
The first testing method can be an observational approach. This method involves simple observation to determine if there’s any color, smell, or taste in your water. If the water still has visible dark brown, purple or black color, metallic taste, and sulfur-like smell, there’s a good change that manganese is still in your water. This means that your water treatment option for manganese wasn’t effective.
Even if your water is clear and odorless after treatment, it’s best practice to conduct another water test to be absolutely sure there’s no trace of manganese in your water.
Frequently Asked Questions
Manganese gets into well water through soils and rocks. Rainwater can also wash it from surfaces into wells and rivers. In addition, human activities such as industrial discharge or mining can also deposit manganese in water sources.
The most common sign of manganese in water is color change. The water might appear purple, dark brown, or blackish. The water will also a bitter, metallic taste and a sulfur-like smell.
According to the Drinking Water Health Advisory prepared by the EPA, drinking manganese-contaminated water above acceptable levels for a long time can affect one’s memory, attention, and motor skills. Infants may develop behavior and learning problems.
According to the EPA, the acceptable manganese level in water is 0.3mg/L (milligrams per liter), while for human consumption (drinking) the level should be 0.05mg/L and below.
It varies depending on the treatment method. A good water softener or reverse osmosis system can cost $500 to $2800. An air injection oxidation system will cost at least $1000.
Reverse osmosis is the cheapest way to remove manganese in water. You can get a good RO system for under $500.
Reverse osmosis is an effective treatment method for manganese, as well as many other contaminants.