Ozone for Iron Removal

Thought I would share my quarterly maintenance report for an ozone iron removal system serving a hog farrowing operation. Iron in the water had been causing high maintenance costs on the power washing equipment used to maintain a sanitary environment. We sized an ozone well water treatment system to remove the measured iron levels at a rate of 20 gallons per minute. The system injects ozone with a venturi, circulates it through a contact tank, and filters the oxidized iron with two sand filters. It has been running for a year and a half now and continues to provide excellent iron removal results. The picture shows two water filters, grey one with clay silt from the well water prior to entering the system. The red one is a post system filter to remove any iron the sand filters missed. I used the Chemetrics iron test kit we sell to verify results. The clear ampule reflects a post-filtration reading of 0.2 ppm total iron. The medium colored ones reflect a pre-treatment sample of 1 ppm iron. The dark-colored one was a test of the backflush water indicating what the sand filters are removing. Overall, the system is operating very well. I changed filters and check valves, measured system performance, and prepared a report for the customer. This summer the demand will be higher on the system, so I will try to get there a little before the next scheduled visit. Ozone can provide excellent results when properly applied and maintained. We are happy to provide quarterly maintenance to keep your ozone system operating at peak performance. Give us a call at 515 635-5854. We’d be happy to provide service for any ozone equipment on the market.

Iron In Your Water? Ozone Can Help.

Rusty stains. A sure sign of iron in your water.

High iron content in water often results in disagreeable metallic taste and unappealing color in cooked vegetables. Although not a health threat, iron bacteria thrive in this water and contribute to biofilm and discoloration. Dissolved iron eventually leads to ugly stains on fixtures and clogged pipes. Removing iron from your water supply is well worth the investment.

The most common piece of water treatment equipment for homeowners is the water softener. Your water softener is designed to remove calcium from the water. It may remove some of the iron, but iron is prone to stick to the resin bed and is difficult to flush out.

An iron filter is a much more effective method for removing iron. There are a variety of filter systems, but they all follow the two step process of oxidizing the iron and then filtering it out. Iron that is dissolved in water can’t be filtered out until it is oxidized or made into larger rust particles that are large enough to be filtered.

Simply aerating water containing dissolved iron will begin the oxidation process needed for filtration. This method is simple, but can introduce some new problems such as increased bacteria growth. It is also slower and difficult to control effectively.  

Some compact home iron filtration devices contain media which accelerates the oxidization process and also serves as a filter to remove the oxidized particles. Like a water softener, these systems require periodic back flushing and eventually require chemical regeneration. The effectiveness of these systems is dependent on PH levels and do not disinfect the water. Iron bacteria can still cause problems by leaving ugly stains on water fixtures.

Adding a chemical feed pump to introduce chlorine, calcium hypochlorite or potassium permanganate increases the oxidation. These systems are able to remove higher iron levels and also serve to disinfect the water. The disadvantage is the ongoing cost of dangerous chemicals.

Ozone is one of the most powerful oxidants. Using ozone to oxidize iron before filtration not only quickly oxidizes all the iron, it oxidizes magnesium and Sulfur compounds as well. Ozone also provides complete disinfection and leaves no chemical residue.  “Ozone can be very effective at treating well water for residential, commercial, or agricultural applications.” Ozone is powerful and requires robust, well-designed equipment to harness its power. Our CWS Ozone Water Filtration System will provide years of service.

Ozone has been used for water treatment for over a hundred hears. It is used extensively for bottled water treatment because it is an effective disinfectant and improves taste and color. Oxidation Technologies specializes in harnessing the power of ozone for a variety of water treatment needs.

Ozone to remove Iron and Manganese from well water

Ozone use for well water treatment

Ozone can be very effective at treating well water for residential, commercial, or agricultural applications. Ozone is also commonly used for municipal water treatment, click here for information on ozone used for municipal water treatment.

Ozone implementation can be very simple, reliable and efficient. Ozone equipment is a one time cost with no salt, or other chemicals to buy. Only minor long term maintenance and electrical costs are incurred. Long term, ozone can be a more cost effective solution, while minimizing lugging of salt bags and chemicals!

When considering ozone for well water treatment keep in mind total water consumption in a day, but also peak water demand. Remember, ozone cannot be stored and must be produced as it is used. Therefore, the ozone generator must be sized based on peak water demand, not average water flow.

Also consider when sizing an ozone system for one application, like iron removal from water, that TOC in the water, while potentially not a primary concern, will need to be considered, as this TOC will also consume ozone and create ozone demand. Be ready to provide complete water quality data when trying to determine the size of ozone system for water treatment.

Every water is different. Also, each contaminate will require different ozone demand, and may require excess contact time, or filtration to remote contaminate. Below we outline considerations when trying to determine the right ozone system for your application. This is by no means a comprehensive list, for specific recommendations for your water, contact our ozone experts today!

Why use ozone for water treatment

Iron removal and filtration:

Iron in water is typically found in the dissolved (Fe+2) state. In this state, iron will pass right through normal filtration but will stain appliances and fixtures over time.

Ozone is used to oxidize iron from Fe+2 to Fe+3. Iron will now bind to filter media, or anything else it touches. Using back-washable filters after the ozone contact tank will capture the now oxidized iron and remove it safely from the water.

To oxidize iron from water 0.43 ppm ozone is required for each 1 ppm of iron in the water. Therefore, multiply your iron level in water by 0.43 to establish the baseline ozone dosage rate for iron oxidation, and removal from water.

The real advantage of ozone use in iron removal from water is the complete elimination of iron bacteria. The reality is that any well water with iron, likely also carries iron bacteria. While this bacteria is not pathogenic in nature it will cause bio-film and other issues on filter beds, piping, and anywhere it can grow. When using ozone, these problems are completely eliminated.

Ozone Injection and filtration system
Example of a complete ozone system to oxidize and filter iron and/or manganese from well water, click on image for a larger view.

 

Manganese removal and filtration:

Manganese in water is commonly accompanied by high levels of iron in water. Thankfully, iron and manganese both oxidize and filter from water similarly and allow for the use of the same basic system.

Manganese is found in water in the elemental Mn form. In this dissolved form manganese will flow through most filters, yet cause staining on all appliances and fixtures over time. Manganese is easily oxidized by ozone to MnO2. MnO2 can be filtered from water, as it will bind to the filter media when in the MnO2 form. Using back-washable filters after the ozone contact tank will capture the now oxidized manganese and remove it safely from the water.

To oxidize manganese from water 0.88 ppm ozone is required for each 1 ppm of manganese in the water. Therefore, multiply your manganese level in water by 0.88 to establish the baseline ozone dosage rate for manganese oxidation, and removal from water.

An important note about manganese oxidation is that if done improperly, a further oxidization state of manganese can be formed. Soluble permanganate MnO4- can be formed with excess ozone, or excess ozone contact time. It is best to use a properly designed and sized system to prevent these MnO4- from forming in your water.

CWS Ozone Filtration System
Ozone system for iron and manganese removal

Ozone for difficult to treat water

Ozone is commonly used for water treatment.  However, ozone alone is not the answer.  Ozone does a great job oxidizing organics, or disinfection.

But when metals, or minerals need to be removed from the water ozone should be used in conjunction with filtration, settling tanks, and ion exchange softeners.  How do you know what filters, and components you need?  Let us help.  We have turn-key prefabricated water treatment systems.

ozone water treatment system
ozone water treatment system

We have designed turn-key systems implementing the following:

  • Ozone Generator from oxygen or dry air
  • Injection system with pump and venturi
  • Ozone contact tank used as a settling tank
  • Back-washable sand filters
  • Ion exchange water softener

We have the experience necessary to make this system work for you.  We can treat the most difficult water, thus saving you money from drilling a new well, or piping water in from an other location.

Ozone filtration system

Common applications are:

  • Iron removal from water (up to 10 ppm)
  • Manganese removal from water
  • Hydrogen Sulfide (H2S) removal
  • Sulfide removal
  • Calcium, or hardness removal

Should you have hard to treat water and need a new solution, contact us, we would be glad to discuss your application.