Removing Manganese and Iron From Raw Water (Options: Pros, Cons)

Iron and Manganese are two minerals that occur naturally in raw water. These minerals aren’t harmful, but essential to human life. However, their presence can lead to bad smells in potable water, as well as unsightly stains on homeowners’ faucets. For this reason, water treatment plants use various methods to remove or reduce these minerals during the water treatment process, some of which require the use of chemicals.

Here are 3 methods of removing iron and manganese from raw water, plus some chemicals that are commonly used in this application. Note that while these products are very effective when used properly, any one of them can have an effect on another aspect of the water treatment program. For this reason, one or the other may not always be the best solution for your water.

 

Oxidation

One way to remove iron and manganese from water is by oxidizing the dissolved minerals to convert them into a different form. Oxidized, iron becomes iron oxide (which is essentially rust), and manganese becomes manganese dioxide. These can be removed by filtration or with coagulants. Products used for oxidation should be added as close to the raw water source as possible. For potable water applications, only NSF/ANSI 60 certified product should be used.

Hydrogen Peroxide

  • Pros: This product is both very effective and economical. This liquid solution is commonly available in a variety of concentrations.
  • Cons: Higher concentrations of this product are regulated by the DHS.

Potassium Permanganate

  • Pros: This product is a powerful oxidizer. Also, more usable product per pound means that it is more cost effective.
  • Cons: This product is an ultra-fine powder, which means that you have to get it into a solution before using it. It has a deep, dark, crimson color that leaves long-lasting stains on your skin after handling. Also, this is a regulated material.

Sodium Permanganate

  • Pros: This is a liquid product that is both ready-to-use and easy to use. This product comes in a drum or tote and is simply fed into the water.
  • Cons: This product is less cost effective per actual product pound, as the majority of the liquid solution is water.

 

Coagulation

Coagulants work by neutralizing the charge of suspended particles allowing them to bond to one another. Particles are then able to flocculate for easier removal. Coagulants are multi-functional and effective to use with many types of suspended particles.

Polyaluminum Chloride (COREPAC)

There are many variations of polyaluminum chlorides, some of which work better for removing manganese and iron than others. Using the wrong coagulant, or using the coagulant incorrectly, may cause your coagulant to technically ‘work’, but not fully strip manganese and iron from the water. To select the best COREPAC product for this concern, testing (on-site or possibly jar testing) must be done.

  • Pros: To some degree, COREPAC can be customized to your raw water source. You can get a more cost-effective coagulation using COREPAC than other traditional coagulants, as much less product is needed for effective results.
  • Cons: COREPAC is more costly per pound.

 

Absorption

Absorptive materials can be added to water for a period of time, then filtered and removed.

Powdered Activated Charcoal

  • Pros: This is an all-natural substance. Also, it is multi-functional; this will effectively remove both seen and unseen impurities such as color bodies, organic carbons, dissolved minerals, smells, tastes, etc.
  • Cons: There are a limited number of quality manufacturers in the market, so this material can be costly.

 

A water treatment plan should be designed specifically for your raw water source. To discuss the best way to remove iron and manganese from your water, or to ask about coagulation tests, contact us and a representative will be in touch shortly. We look forward to speaking with you!