Stephen Bell of Trojan Technologies: The Advantages of UV Treatment
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rojan Technologies is a leading manufacturer of municipal, residential, and industrial ultraviolet (UV) light water treatment technologies. It has broad experience and a huge install base that includes under-sink systems purifying a few liters of water a minute, major municipal facilities that treat millions of gallons of water a day, and even off-grid installations that ensure safe water supplies in remote locations. In this interview, Trojan Technologies President Stephen Bell tells Irrigation Leader about the advantages of UV treatment’s flexibility and about Trojan’s work around the globe. Irrigation Leader: Please tell us about the history of Trojan Technologies and about its current product lines. Stephen Bell: Trojan was founded about 43 years ago as a toolbox manufacturer. Its starting point was that it had a new technology related to the UV treatment of water for contaminants. Over time, it made a number of acquisitions and grew significantly. I received a letter from the founder about a month ago saying, “I remember when we were valued at $285,000 and all the staff would come together on Monday mornings around a coffee table to look at the week ahead.” Things have grown by more than a thousand times since then. Trojan has added other businesses that work on industrial water treatment and residential UV water treatment. Our UV technology is not just for municipalities; it includes systems that you may have in your home, especially if you’re drawing water from untreated sources such as a well, borehole, or rainwater collection system. In addition to those, we are treating water in microelectronics and vaccination production facilities. We’ve broadened over the years to filtration technologies as well as pure water and softness technologies. Irrigation Leader: How does UV light work as a water treatment method, and how does it differ from other treatment methods?
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treatment facility, by contrast, can’t be turned on and off instantly. Likewise, as long as you’re connected to electricity, you have the ability to generate UV and to disinfect water. You don’t have to worry about transporting truckloads of chemicals. The UV treatment process has also evolved to become energy efficient. Massive strides have been made over the past 40 years in terms of the energy needed to generate a certain dose or amount of UV. In the last few years, I’ve seen some customers who will install a new plant or upgrade their facility and receive a payback in 3 years or less based on electricity savings alone. Irrigation Leader: How long does water need to be exposed to UV light for the treatment to be effective? Stephen Bell: Generally speaking, the reactions in simple processes such as disinfection are incredibly fast, on the order of seconds. The question is more about how much UV energy is required to achieve the treatment goal. This relies on a variety of things, such as UV transmittance, which refers to how easy it is for the UV light to get through the water. Distance and intensity are also important. UV is not something like an activated carbon bed or tank that can require a certain amount of settling or contact time. We have small systems that treat 10–20 liters per minute and extremely large municipal systems that involve entire trains or even a 48‑inch diameter pipe that water is traveling through. The sizing and the speed with which water can travel through the system depends on the dose of UV that is required. The calculation is much more critical for large irrigationleadermagazine.com
PHOTOS COURTESY OF TROJAN TECHNOLOGIES.
Stephen Bell: The technology works by sending light through the water that stops the reproductive elements of viruses and other contaminants. It’s all about stopping evolution. That’s what makes UV so flexible: It won’t change the fundamental makeup of water, but it will stop any further contamination or the growth of contaminants. When UV is used for contaminant removal, it is usually used with an accelerant or some other chemical. UV can be used in a multitude of different applications in many different ways, hence its viability as a treatment method for water types from drinking water to wastewater. UV’s flexibility is absolutely a key advantage. When you switch on the system, it’s ready to go quickly. A chlorine
A Trojan water disinfection system installed at Wellington Water in Wellington, New Zealand.
