Disinfecting Water - the MIOX Solution

Imagine, tap water with no chlorine taste nor the chemicals that burn your eyes! And.......is more effective than Chlorine in disinfecting the water we use. Welcome to the science and technology of Mixed-Oxidants (MIOX™)

UAF has successfully been using MIOX to disinfect the drinking water on campus since April of 1997. Prior to the use of MIOX, UAF was using 1 ton cylinders of chlorine gas to provide disinfection of the water. By moving up to the on-site Mixed-Oxidant generators, UAF has improved the drinking water quality along with increasing our ability to more efficiently and effectively disinfect your drinking water.

By removing the chlorine gas chlorination system, we eliminated all of the hazards associated with the shipping, storing, handling and applying of chlorine gas as a disinfectant. The only thing we do now is add salt to a small storage tank to produce a brine solution which in turn is fed into an enclosed electric cell. The liquid that the cell produces is called the MIOX solution. The MIOX solution being produced by the cell is then collected in a medium sized holding tank that we refer to as the "day tank". The solution is then fed from the "day tank" directly into the domestic drinking water main. The correct feed rate of the solution is determined by the rate of the domestic water flow going to campus. As the flow of water to campus increases, the MIOX feed pump also speeds up in order to maintain the established disinfectant residual. Conversely, as the flow of water to campus decreases, the MIOX feed pump slows down.

The Problem with Chlorination Systems

The use of chlorine gas to disinfect water has prevented disease and saved millions of lives over the past century. However, traditional chlorination equipment is not safe and is frequently unable to meet the requirements of the Surface Water Treatment Rule, Disinfection/Disinfection By-Products Rule, and other US Environmental Protection Agency water quality regulations. Uniform Fire Code and BOCA fire codes require costly containment equipment for chemical handling and safety, but this containment equipment only mitigates the hazards of transporting, storing, and handling hazardous chlorine products. Concerns over possible carcinogens, the hazards of chlorine transport and handling, corrosive effects, and unpleasant tastes and odors from chlorine use are prompting water systems to move to MIOX on-site mixed-oxidant generators to improve water disinfection.

Sometimes, Simpler is Better

The heart of the MIOX system is a patented cell that is simpler and produces a more effective solution than conventional forms of chlorine disinfection or on-site hypochlorite generators. The cell utilizes dilute salt water and direct current to generate a solution of chlor-oxygen mixed oxidants which is more effective than chlorine, and leaves a durable chlorine residual. This solution is collected in a tank and injected into water at rates appropriate to meet treatment objectives.

MIOX systems are fully automated and run unattended for days, self-diagnose fault conditions, and generate a constant concentration of oxidant when needed. No hazardous chemicals are required for operation nor generated by MIOX equipment. MIOX-treated water has been shown in laboratory and pilot tests to kill or inactivate 99.99% of microorganisms (such as Giardia and Cryptosporidium) that are virtually immune to chlorine treatments. MIOX-treated water does not impart a chlorine odor or taste at normal treatment levels. Imagine, tap water with no chlorine taste nor the chemicals that burn your eyes!

Here's How it Works

The MIOX cell, the heart of the technology, generates a mixed-oxidant solution electrolytically from a sodium chloride (NaCl) brine. Electrolysis of chloride solutions has been used for decades to generate chlorine (Cl2) and hypochlorite (OCl­). The key difference is that the MIOX cell has a patented process that separates solutions generated at the anode (oxidants) and at the cathode (reductants). In operation, the MIOX cell generates a solution made up of chlor-oxygen species. The mixed-oxidant solution concentration is determined by the size of MIOX equipment.

The solution must be injected at a concentration necessary to (1) satisfy the oxidant demand of the water, (2) effect the desired degree of disinfection, and (3) meet the standard for disinfection residual. The dosage necessary varies according to the individual water system.

Total Dissolved Solids (TDS)

Although MIOX uses brine to produce the mixed-oxident solution, addition of salt (a component of total dissolved solids (TDS)) is negligible. Most water systems already contain TDS levels around 150 mg/L, which is increased by a small amount when using any form of chlorination for disinfection. The current MCL for TDS is 500 mg/L, and as you can see from the figures below, MIOX does not add enough TDS to be of concern. In fact, research shows that too little salt may actually increase your odds of having a heart attack! An average MIOX unit adds the following levels of TDS and Na+ to the water:

  SAL-80 MIOX-500 TDS: 6 mg/L 4 mg/L Na+: 2 mg/L 1.6 mg/L

Just a side note: a 12-oz. can of Coke contains 140 mg/L of sodium, which is 63 times higher than the level of sodium added to the water by a SAL-80!

Water Analysis Report (.pdf)

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