Process Cooling

Water Treatment

Trends in

Water Treatment

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By Jim Green,

Suez Water Technologies & Solutions

Supply chain challenges and other forces have provided the impetus for cooling water treatments.

The seeming chaos of the last couple of years has had a painful impact on water treaters and facility teams alike. The effects of COVID-19 on manufacturing and logistics have stressed the supply chain in ways never imagined. The resulting shortages of core, primary materials historically available in excess are driving several “force majeure” actions.

In addition to these sourcing challenges, tariffs have exacerbated the issues, resulting in a meteoric rise in material and logistics costs. Increased and changing regulation is driving the need for new, safe and environmentally friendly technologies. Ongoing challenges with maintaining sufficient numbers of highly trained water experts and operators are stressing operations across the board.

As the adage goes, “With great pain comes great change.” This unique confluence of events is driving substantial changes in cooling water treatment. These capabilities may help plant operators function with higher reliability, longer run times, cleaner systems, improved decision-making, reduced maintenance and support, and, ultimately, a lower total cost of operations (TCO).

This article will explore some of the current trends in cooling water treatment, driving factors for change, and questions to ask your supplier.


Sterling

Supply Chain Effects

To understand the current trends in cooling water treatment, let’s take a step back and understand the biggest impact on recent changes: supply chain and research investment.

The supply of core materials used to produce cooling water treatment is impacted by plant closures, logistics and raw material availability. These issues could lead to your supplier activating a hyperinflation clause in your contract, force majeure or price increases.

For example, isothiazolin, bronopol and dodecylguanidine hydrochloride (DGH) — common non-oxidizing biocides and product preservatives — have had on- and off-again availability. Acrylic acid, the backbone of the workhorse polymers used as dispersants and inhibitors in cooling water, was in short, rationed supply, and phosphonates used for deposition control are moving in the same direction with two to five times cost increases. Azoles, used as corrosion inhibitors for copper metallurgy, were hit with tariffs and experienced an immediate, significant increase in cost. Additional supply chain challenges with the logistics of cargo shipping have forced intermittent usage of air-freight deliveries, resulting in up to 25 times increases in cost.

The pains of the supply chain challenges have forced water treatment suppliers to dust off research from 50 years ago, review technologies they put on the shelf for later, develop analytical engines and modeling capabilities to fast-track research and development projects, and get laser-focused on understanding and delivering value to facilities. In short, research and development efforts that were on life support have been jump-started with investment and focus. As a result, new technologies will reach the market.

Several new terms are being used by water treatment companies, and they must be understood. Widely used terms such as “non-phosphorus,” “Non-P,” “phosphate-free,” “non-depositing” and “deposition-free” terminology often are related to a new class of chemistry for cooling water.

Older treatment programs that relied on phosphate chemistries for deposit and mild steel corrosion control are being replaced by polymeric and filming technologies that provide mild steel corrosion control without any phosphate component. By eliminating phosphate, the risk of calcium phosphate deposits is minimized or eliminated, allowing facilities to operate their process systems under harsher conditions for longer run times, and improving energy usage in deposition-challenged chiller systems. These “non-phosphate” approaches have additional benefits too, including reducing algae growth rates, reducing biocide usage and providing the ability to meet stricter phosphorus discharge limits.

Typically, these programs can be implemented for incrementally more than a current program’s cost, and they can be put in place by simply changing out the current chemical products for the new ones. Still, there are a couple of things to be aware of and a couple of key questions to ask your supplier about the technology they offer.

Key points to consider when implementing a non-phosphorus program include:

  • Tin is commonly used in many programs. Tin is not stable in the presence of oxidizing biocides (hypochlorite, bleach, bromine, etc.) and will precipitate out of solution, causing an increase in corrosion of mild steel.
  • Zinc also is commonly used and has been used for 50 years as a supplemental corrosion inhibitor. It is a heavy metal and an EPA priority pollutant, however. This is something to move away from, especially if you are interested in a sustainable, environmentally friendly treatment program.
  • A program utilizing a proprietary carbon-hydrogen-oxygen-based technology with a surface film formation catalyst has been developed. It is stable in the presence of oxidizing biocides.


Questions to consider asking your supplier:

  • Do you have a technology that does not contain tin or zinc as part of the program?
  • Does your program include all the current monitoring equipment available, including real-time online corrosion, deposition and chemical-feed monitoring?


With the increases in costs associated with azoles used to protect copper and copper alloys in your system, new technologies exist that may help mitigate the cost increase while providing the same or better corrosion protection. The most common azoles are tolytriazole (TTA), benzotriazole (BZT) and chlorotolytriazole (Cl-TTA). There are two main alternatives available to replace these technologies:

  • Non-triazole azoles (e.g., imidazole derivatives).
  • Engineered copper filmers.


Blue

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Imidazole technologies were investigated in the 1970s and 1990s and provided good performance, but they also faced several challenges. They were much less soluble than other technologies, meaning they could precipitate out of solution, either in the product container or in the cooling water, before they had a chance to prevent corrosion in cooling water systems. These materials also were linked to the same supply chain as TTA and BZT; therefore, they still experienced the same price volatility as the competing molecules. The most concerning issue by far was that with pyridyne substituted imidazoles, like 2-(2-pyridyl) benzimidazole, where it was found that there are significant handling concerns for the final product, such as inhalation, which can lead to reproductive issues in those exposed to it.

Engineered copper filmers (ECF) are another safe alternative to imidazole and current technologies. ECF technology offers the ability to reduce azole concentrations by as much as 75 percent, thereby reducing toxicity in the effluent water and mitigating the cost impact of tariffs and price increases. The technology, provided as a single product to feed, is effective across neutral and alkaline pH cooling water operations and provides better protection than the current benchmark azole technology, Cl-TTA. It is also halogen stable, meaning that like Cl-TTA, its performance is unaffected by the addition of oxidizing biocides.

Questions to consider asking your supplier:

  • Do you offer an alternative copper corrosion inhibitor?
  • What is the human toxicity rating for your copper corrosion inhibitor?


With the increase in interest in green technology for water treatment and so many claims made by suppliers about greener chemistry, we’d be remiss if we did not touch on this topic. Whether you call it sustainability, green initiatives or green chemistry, almost all companies strive to offer products that are better for the environment. Unfortunately, sometimes to gain an edge in today’s market, some claims are overreaching or misleading.

A process known as “greenwashing” is hitting water treatment products as much as many consumer products. It is a practice of employing a marketing spin to convey a false impression, misleading information or unsubstantiated claims about the environmental benefits a product offers. Fortunately, the U.S. Environmental Protection Agency (EPA) has worked to help suppliers and plants alike understand how green a product is using the 12 Principles of Green Chemistry.

Automation Advancements

The original iPhone was launched in 2007 and the iPad in 2010. Consider the changes and advancements in those technologies in the 10 to 15 years since launch. Chips have become smaller while at the same time, processing power has increased and software has become sophisticated. Most importantly, wireless connectivity, with 5G making inroads, has become faster and more robust. The same is true of automation technology in cooling water. Smaller, entry-level control systems are more robust, capable of integrating and acting on information from various sensors and inputs. This is leading to their use in even some of the largest industrial cooling water systems.

Edge devices are changing how data is controlled and expanding the ability to gain “smart” insights from data. In cooling water applications, an edge device or controller takes data from multiple sources: sensors (pH, ORP, etc.); advanced monitoring devices like deposition or corrosion monitors; feed pump outputs; and tank level sensors. The edge controller manages the flow of that data to cloud-based data services that can then cost-effectively analyze the data automatically and provide intelligent direction to the edge device for control. This means that the edge device itself can remain relatively inexpensive because it does not have to do any of the processing itself. Such an approach offers facility managers the ability to take advantage of advanced analytics and artificial intelligence only available in the cloud.

Finally, significant advancements have been made in real-time performance monitoring. The ability to switch from relying on the analysis of chemical residuals to understanding true performance allows facility managers to increase production and lower the total cost of ownership. Real-time deposition monitors can model challenging processes and operations, and they can provide advanced warnings of deposition events. Online corrosion probes can provide real-time corrosion rates, giving users insights into corrosion performance. Combining tank-level monitoring and chemical feed pump output monitoring can help users ensure that the correct amount of product is being fed, avoid run-out situations, and enable automated chemical ordering/refill.

One area where significant progress has been made is in online microbiological monitoring. There are a host of technologies on the market today. Some automate well-known methods like ATP testing. Others utilize dyes like erythrosine and a limited-data, optical calibration curve, or an electrochemical measurement method. While these devices can provide some directional information based on bulk water readings, with microbiological control, the most important factor is understanding biofilm growth and its impact on heat exchange. The most capable and accurate real-time devices use a heated surface with flowing cooling water to mimic the operating conditions and measure biofilm growth.

Complimenting online microbiological monitoring are advancements in Legionella monitoring. Legionella is a dangerous organism in cooling water applications that can lead to legionellosis or Legionnaires’ disease if it is not controlled. Businesses have been shut down for extended periods due to the COVID-19 pandemic while leaving water systems idle, creating the perfect environment for Legionella bacteria to grow.

Fast, accurate, and portable DNA analysis for Legionella is now available. Instead of waiting days for incubation and laboratory analysis, users can have an accurate, on-site analysis completed during a service visit to confirm that Legionella is under control.

Questions to consider asking your supplier:

  • Do your monitoring technologies utilize a heated surface that mimics operating conditions and can provide real-time trends online?
  • Can you provide on-site, DNA-based Legionella testing during service visits?


Insightful Analytics. You have a great chemical treatment program. You regularly test and capture chemical parameters. You have implemented real-time monitoring of deposition, corrosion and microbiological growth. Now, what do you do with all that information?

With all of the data being pushed to and cataloged in the cloud, it is now possible to analyze it in ways that were never available previously. Fast, powerful analytics can provide valuable information and insights to facilities. Everything from simple product calculations to complex condenser efficiency monitoring and predictive modeling of process applications can be handled with cloud-based analytics. These tools offer suppliers the ability to deliver a higher level of service consistency even with personnel challenges. They also provide facility operators the ability to modify operations to maximize production, profitability and reliability with minimal manpower input.



Jim Green is global marketing leader for Suez Water Technologies & Solutions, Trevose, Pa. For more information from Suez Water, call 866-439-2837 or visit suezwatertechnologies.com.

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