All posts by Aileen Culling

MIOX Short Film: Eliminating Chlorine Gas in Richland, WA

Richland, Washington is home to a variety of environmental habitats ranging from arid shrub-steppe to marshlands. The area is recognized as one of the most diverse, scenic and biologically productive eco-systems in the entire Pacific Northwest. Thus, water conservation and protection are very important to the community.

Richland, Washington provides reliable, high quality water services to their citizens by using proven treatment techniques and best management practices. MIOX is proud to be one of their trusted water treatment technologies.

Alternative to Bromine Improves Cooling Water Microbial Control and Overall Treatment

Andrew Boal, PhD
MIOX

Presented at the 2015 Cooling Technology Institute Annual Conference New Orleans, Louisiana – February 9-12, 2015

ABSTRACT

Ammonia in the cooling loop poses an additional challenge for hypochlorite or oxidizing biocides in controlling the microbiological activity since chloramines are typically seen as less effective biocides as compared to free chlorine. Often, cooling tower biocidal treatment is accomplished with bromine based non-oxidizing biocides coupled with the occasional application of isothiazolin or gluteraldhyde. This paper demonstrated that Mixed Oxidant Solution (MOS), a biocide produced through the electrolysis of sodium chloride brines, is a highly effective biocide. Without overcoming ammonia, and in high pH environments, MOS was able to successfully control the microbial populations in the cooling tower waters of a major semiconductor facility in the US, where ammonia contaminated wastewater is used as part of the makeup water for cooling towers.

Download CTI Article

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Technical Brief: Electrochemical Generation

The applications and scientific mechanisms of disinfectants generated on-site using salt, water and electricity

By Andrew Boal, Ph.D.

When you are researching a product, how frustrating is it to conduct your due diligence only to find answers segmented across dozens of sources? I’ve been there before.

That is why I wrote this digestible, technical overview of electrochemical generation, also known as on-site generation (OSG), to outline the applications and scientific mechanisms of this revolutionary technology in order to make your life easier and help you do your job better.

Many water treatment professionals are moving to OSG to produce disinfection chemistry on-demand, leaving traditional oxidizing and non-oxidizing biocides behind.

The benefits Continue reading

Hospital Eliminates Legionella Outbreak in 3 Weeks

This wasn’t a happy story. At least at the beginning… They had a Legionella outbreak that their previous water treatment solution didn’t eliminate.

You can read the full story here, but with MIOX they were able to:

  • Eliminate 100% of Legionella within 3 weeks
  • Lower their oxidant dosage
  • Remove hazardous chemical drums from inside the hospital
  • Reduce water and energy footprint

Click here for the full story.

OSG Process Flow

On-site generators (OSGs) produce chlorine when a solution of sodium chloride is passed through an electrolytic cell and electricity is added. In essence, OSGs take a solution of sodium chloride (salt) and water and apply electricity, which produces chlorine and other oxidant species.

Water coming into the OSG goes through a softener, and then splits into two lines. One line is used to feed a salt filled tank, creating a saturated brine. The other line enters the OSG, acting as a dilution stream prior to the electrochemical process. Saturated brine is then precision mixed with the softened water stream prior to entering the electrolytic cell. Application of an electrical current to the cell results in the production of an oxidant solution from the diluted brine.

After leaving the electrolytic cell, the oxidant solution is temporarily stored in the oxidant tank. Then it is metered or injected into the water moving through the treatment process, typically with similar equipment as an existing chlorine system.  Injection options include a venturi or other eductor -, centrifugal feed pumps, or chemical metering pumps. Sites with multiple injection points may use a combination of these options.

Hydrogen gas is also produced inside the electrolytic cell and is removed from the cell and the oxidant storage tank through vents and/or dilution air blowers.

Process Flow Diagram

Process Flow Diagram

The OSG operates via a signal from the level switch/transmitter located in the downstream oxidant tank. When the tank is empty, the transmitter/switch sends a signal to the Programmable Logic Controller (PLC) to put the OSG online. As soon as the tank is full of oxidant, the transmitter/switch sends a signal to the PLC to put the OSG in standby mode. This means very minimal operator attention is required during normal operation.

Many communities are turning to OSGs for their water distribution systems because of the benefits, including better safety, high-quality disinfection, greener operations, and substantial economic savings. Because of the benefits that OSGs provide, many companies prefer OSG systems as opposed to more traditional chlorine delivery systems such as chlorine gas, concentrated sodium hypochlorite, and bulk calcium hypochlorite.

Click here for a tech brief on the science behind OSGs.

The Most Effective Way to Disinfect Cooling Towers

Disinfection is a critical aspect of cooling tower water treatment for operational reasons like eliminating biofilm to maximize heat transfer efficiency and minimize microbial-induced corrosion.

We all know that cooling waters containing high levels of ammonia, which increases the complexity of the disinfection process, are commonly found in the ammonia production industry.

But here’s the thing…

Ammonia in cooling towers is commonly assumed to interfere with hypochlorite-based disinfection programs, which are in-turn expected to be insufficient alone to control microbial populations and require additives such as bromide or non-oxidizing biocides to provide sufficient disinfection.

However

There is a growing body of evidence demonstrating that disinfection of ammonia containing waters with on-site generated Mixed Oxidant Solution (MOS) can effectively control microbial populations in these waters without additives. MOS is an industry-proven disinfection technology which is produced on-site through the electrolysis of sodium chloride (salt) brines, providing cost-savings, improved disinfection efficacy, and increased worker safety.

Recently, a large ammonia production facility converted their cooling tower disinfection program from a chlorine gas/bromide combination to treatment with MOS only.

And we have a side-by-side comparison of these two disinfection programs at the same facility to show the real difference.  

Read More from Andrew K. Boal, Ph.D…..

On-Site Generation: A Safe Replacement for Chlorine Gas in Water Disinfection Applications in Ammonia Production Facilities

Abstract Text: Disinfection is a critical component of industrial water treatment programs, and is especially the case in waters used in cooling towers. Cooling water that has not been properly disinfected can result in the growth of biofilms, which can damage equipment and allow for the proliferation of pathogenic bacteria which can result in increased human health risks. Chlorine gas is commonly used as the primary oxidative biocide in large scale industrial cooling water treatment programs, including many ammonia production facilities. While chlorine gas is inexpensive, facility managers are moving away from chlorine gas due to the hazards that this chemical presents not only to the work force, but also to surrounding communities. While there are several options for chemicals that can replace chlorine gas, On-Site Generated (OSG) systems are an ideal choice to deliver an oxidant for disinfection applications using the safest means possible. OSG processes work through the electrolysis of sodium chloride brines to produce sodium hypochlorite based oxidant solutions with active chlorine concentration of less than 0.8% and at a mild pH. These solutions are much less hazardous than bulk delivered oxidants, which are typically provided in concentrations of 10-15% with solution pH values of over 11. This presentation will provide an overview of OSG processes and systems and will describe in detail the replacement of chlorine gas with OSG systems for cooling water disinfection at a major ammonia production facility.

Chlorine Dioxide Vs. MIOX’s Hypochlorite Generator

More effective on tough-to-kill organisms, MIOX Mixed Oxidant Solution provides all the benefits of chlorine dioxide, without the hazards of chemical storage or explosion risk.  Biofilm control is easily achieved using only simple table salt and water and your base chemicals – no more strong acid or sodium chlorite.  So you get better control and improved safety all at 1/10th of the cost of chlorine dioxide!

Video Transcription:
Chlorine Dioxide: the solution and the precursor are extremely hazardous.

It’s so explosive that the US department of transportation won’t even allow you to transport it (unless it’s been stabilized or dilute the CIO2 solutions to 3000 parts per million). It’s so risky, that gas masks are required when off-gassing is higher than .1 parts per million in the air. It’s so reactive that its precursors violently react to organic material like: wood, paper, oil, even gummy bears.

It off-gasses so quickly, it may not be effective in certain applications. And to top it off, Chlorine Dioxide is very expensive.

Now there’s a better solution. In most applications, MIOX is as effective as Chlorine Dioxide for biofilm removal and water disinfection including:

  • Sulfur-reducing bacteria (SRB)
  • Acid-producing bacteria (APB)
  • Hydrogen sulfide
  • Cryptosporidium Parvum Oocyst
  • Giardia muris cyst
  • Pseudomonas aeruginosa
  • Legionella Pneumophila  

And MIOX is much safer. You can generate MIOX on site using salt, water, and electricity. And MIOX is much more cost-effective: up to 10x cheaper than Chlorine Dioxide. Chlorine Dioxide may be offered by your water treater, and it may work well. But is it really worth the risk or substantial cost?

Case Study: How This Centralized Cooling Plant Controls Bacteria

This customer wanted a safe, sustainable and “chemical free” biocide for their cooling towers and closed loop, and so they decided to try our MIOX Mixed Oxidant Solution (MOS) in a phased test.

After the test was rolled out and the systems were in place, it was discovered that more biocide had been used than previously documented at this location. As a result, the MIOX system was not the proper size to handle the necessary volume, so there was concern that it wouldn’t be able to achieve optimal operation.

The results?

The client replaced their proprietary biocides (stabilized bromine and glutaraldehyde) and got greater microbial control, despite the undersized MIOX system in the test phase.

How is that possible?

Read the full case study here.

Tech Brief: Electrochemical Generated Disinfectants by Dr. Andrew Boal

MIOX electrochemical generators, or On-Site Generator (OSG), combine salt, water and power to generate your water disinfection on site and on demand.

The electrolytic cell, where the oxidants are produced, is central to the OSG process. Electrolytic cells consist of two electrodes, the anode and cathode. The cells are arranged so both electrodes make contact with the water and brine solution mixture. When the OSG is activated, an electrical current flows through the cell, causing chemical reactions on the surfaces of both electrodes that eventually produce the disinfectant.

MIOX electrolytic cells are developed with a proprietary geometrical design, electrolytic scheme, and solution flow characteristics. This proprietary knowledge is what allows MIOX to lead the hypochlorite market in terms of efficacy, stability, ease of use, safety and, in most cases, cost.

MIOX works in partnership with your site and current water treatment professional. We offer flexible procurement options ranging from capital sale, lease and rentals.

Read our Tech Brief: Electrochemical Generated Disinfectants by Dr. Andrew Boal for the full chemical reaction, technical explanation and applications breakdown. Click here to access. the PDF online.

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