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cooling tower water treatment

The primary uses for cooling towers include heating, ventilation, air conditioning and other industrial purposes. They provide a cost-effective and energy-efficient solution for systems in need of cooling. A cooling tower is designed to remove heat from a building or facility by spraying water down through the tower to exchange heat into the building, according to the Centers for Disease Control and Prevention (CDC). Heat exchanges as the air pass through the water, and some water evaporates. Industries that typically utilize large cooling towers include power plants, petroleum refineries and various manufacturing facilities. The towers vary in size from large hyperboloid structures to smaller ones on the rooftops of shopping centers, hospitals and universities. 

Four Major Cooling Tower Issues

It is essential for facility managers who oversee buildings that utilize cooling towers to monitor and control the four major types of concerns. According to All Kote Lining, these issues include:

  • Biological contamination: Cooling towers are an ideal place for unwanted bacteria to grow due to the hot and humid conditions. These contaminants, presented as biofilm on internal components, aren't good for our health and worsen the tower's efficiency. The United States National Institutes of Health notes that 80% of chronic infections are biofilm related.
  • Corrosion: When the air, sodium and other chemicals in our water supplies are left unchecked to run through a cooling tower system, they will start to eat away at the metal and ultimately cause leaks.
  • Fouling: Clogging of cooling surfaces or pipes with debris, dirt and dust is known as fouling. When water cannot make it into and pass through the fill as designed, the air is not cooled correctly, meaning the system has to work longer and harder to achieve the same results.
  • Scaling: The build-up of minerals in the water can create layers that will damage the efficiency of the cooling down process. Certain minerals, like calcium, that are part of the high-heat system break down and deposit on the cooling tower heat-exchange surfaces, causing operating costs to increase. 

Commercial Water Purification Systems

Most cooling towers use filtration systems as the first level of water treatment. Commercial water purification treats large volumes of water at high-flow rates, according to Water Professionals. The type of water treatment utilized in a system will largely depend on the desired purity level of the final water makeup. Water treatment methods commonly used in commercial water purification systems include:

  • Softening: Soft rainwater picks up naturally occurring dissolved minerals such as calcium and magnesium carbonates as it passes through the soil. Most source water contains some amount of hardness. Hard-water softening prevents the buildup of those hard minerals in equipment and piping. 
  • Dealkalization: Alkalinity measures water’s ability to neutralize the acid. This process removes anions such as bicarbonates, carbonates, sulfates and nitrates with a chloride anion exchange. According to Absolute Water Technologies, this process treats softened water with a chloride form an anion resin that exchanges chloride ions for anions in the feed water. 
  • Demineralization or deionization: This process utilizes in-plant deionizers that consume caustic and acid automatically at pre-established intervals. These deionization systems require frequent maintenance and can be costly to purchase upfront. 
  • Reverse osmosis: These systems can separate water molecules from alternative dissolved solids within the water, such as carbonates, sulfates, silica and nitrates. They can also avoid wasting water by using recirculation.
  • Microfiltration: This process physically removes suspended solids from the water, usually through a membrane. Crossflow separation uses a feed-stream introduction into the membrane under pressure and passing over the surface in a controlled flow path.
  • Multimedia filtration: This pressure filter vessel utilizes three or more different media than a sand filter which typically uses one grade of sand as the filtration media. Using only one media can result in very limited use since particles become trapped at the top of the filter bed, so multimedia filtration offers differing masses that help the particle naturally stratify during the backwashing process.
  • Nanofiltration: The design and operation of nanofiltration are very similar to that of reverse osmosis. It recycles wastewater through higher flux rates but uses less energy than a reverse osmosis system.
  • Ultrafiltration: This process utilizes a semi-permeable membrane to physically remove suspended particles from water based on particle size and pore size. It is typically tighter or offers a smaller pore size than microfiltration.

cooling tower water treatment

Cooling Towers and Bacteria

Cooling towers contain large amounts of water and are potential breeding grounds for Legionella bacteria if not properly disinfected and maintained. Legionnaires disease is a severe and sometimes fatal type of pneumonia caused by Legionella bacteria found naturally in freshwater environments, such as lakes and streams. The bacteria can become a health concern when they grow and spread in human-made building water systems like cooling towers and large, complex plumbing systems. 

In 2018, nearly 10,000 cases of Legionnaires’ disease were reported to health departments across the United States. In just the last three months, there have been more than 50 confirmed cases in the country, according to HC Info. According to the CDC, water-management programs help identify hazardous conditions and utilize processes to minimize the growth and transmission of Legionella and other waterborne pathogens that build up in water systems. 

Cooling Tower Solutions

If cooling towers are left untreated, organic buildup, scaling, erosion and fouling can leave the plant in an unproductive state, causing plant downtime and consequently requiring costly equipment replacements. Biofilms can contain sulfite-reducing or iron-depositing bacteria that destroy steel, wreaking havoc on water cooling system pipes. According to Water Technology, this microbiological corrosion is 10 to 10,000 times quicker to develop and 10 to 100 times more aggressive than standard corrosion. A biofilm layer of just 0.1 millimeters can reduce efficiency so much that the associated electricity costs to power the plant can increase by a factor of four compared to a system containing the same thickness of calcium carbonate scale.

High-capacity commercial water purification systems can effectively remove chlorine, rust, sediment, sulfates and more. In addition to the water purification system, facility managers must consider the solutions they use to keep these systems and towers clean. HOCl is ideal for commercial applications to protect these water treatment systems from harmful bacteria like Legionella. Our HOCl solution disinfects without using harsh chemicals that are detrimental to our environment and long-term health. It is also free of dangerous fumes and volatile organic compounds commonly found in other products such as bleach. Differences in the production of HOCl create distinctions in its effectiveness, strength and corresponding uses. Watch to learn more about the science behind our HOCl.

cooling tower water treatment

Why Work with Emerald Prairie Health

Before developing your strategy for managing the cooling tower, there are a few key considerations: water chemistry, flow rate and scaling potential, the required quality of treated water as well as brine management options. During the consultative process, we conduct a very detailed discovery to look at these items. We will also examine the facility and desired goals to better determine the right chemistry for the job and your industry.

The proper concentration of a disinfectant is important to achieve the best results for each situation. Some products will have different dilutions depending on the desired use of the product. While some disinfectants may be more effective at higher concentrations, these levels may be limited by the degree of risk to personnel, surfaces or equipment. Overdilution of a product may also render the disinfectant ineffective to the target microorganism. Our unique discovery and client consultation process helps you achieve the most accurate chemistry for the job utilizing our team’s decades of experience in the field.

Our eco-friendly line of HOCl-based surface cleaners and disinfectants are formulated with 100% natural ingredients, contain no harsh chemicals, alcohol, bleach or phosphates and are 99.9% effective against bacteria, viruses, spores and fungi. We offer several options based on your commercial cleaning needs:

We would love to provide you with a consultation about your business’s commercial cleaning and water management needs. Watch to learn more about our team. If you’re ready to get started, contact us at!

Emerald Prairie Health is a purpose-driven company, committed to providing products that make for a cleaner and healthier world. We provide all-natural, non-toxic and environmentally friendly cleaning and disinfectant products that help protect against harmful pathogens such as bacteria and viruses. Our products are 99.99% effective with no fumes or chemical residues, allowing you to return to the office, classroom, business and your life in a clean and healthy environment.

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