By Rick VanSant
The world is moving toward best-practice water treatment protocols whereby, in simple terms, we will treat water when we take it out of the environment, treat it before we reuse or recycle it, and treat it before we put it back. Increasingly, this means decentralized, POE residential, institutional or industrial potable water treatment, POU treatment of water for reuse and, of course, of wastewater to ever higher standards before reintroduction to the water table or surface water. Typically, these applications require treatment for flows under one or two MGD (million US gallons per day), often much less.
Clearly, no pun intended, the composition of pre-treatment water is growing more complex; therefore, acceptable standards posttreatment are adjusting, as is the combination of multiple technologies or barriers required to achieve the target standards after treatment. UV disinfection technology is an important technology for microbiological reduction, and according to XPV Capitol Corporation, Frost & Sullivan and Siemen’s annual report, it is the fastest growing segment of the $50 billion (USD) water treatment technology market annually.
UV disinfection systems are increasingly incorporated as a final microbiological barrier for the following reasons:
- UV is a broad-spectrum solution—with enough power for enough time, it can effectively reduce all pathogens, including those resistant to chlorine, like cysts.
- UV technology produces no wastewater stream and no DBPs.
- It is an environmentally neutral treatment technology—simply put, it puts nothing into and takes nothing out of the water flow.
- With advanced UV technology, effectiveness can be monitored in real time, not hours or days after sampling, and remotely.
- Advanced UV systems are small-footprint installations, making retrofit easy and lowering the cost of supporting infrastructure compared to alternatives.
- UV systems offer low capital cost and low-cost operating solutions when compared to most alternative disinfection technologies, including much lower energy costs.
- Advanced systems with self-cleaning mechanisms and temperature management are relatively simple, low-maintenance solutions.
Typically in past decades, UV for residential or even institutional and commercial potable water treatment was often a low-awareness afterthought. Conventional, small UV systems with no monitor and with no validation were installed as a disinfection barrier, with the expectation that they would provide safe drinking water, meaning they might reduce potential pathogens to a level considered acceptable. Now, evolved UV systems incorporate on-board monitors that will provide an alarm if the systems might be operating below minimum standards for effective treatment. Increasing numbers of regulatory jurisdictions are aware of, accept, and now require UV systems that meet the same high standards as were previously only used in large municipal treatment plants. This is true in both developed and developing nations. It is now possible and affordable in smaller applications, like residences, schools, hospitals, hotels and similar applications, to create an effective multi-barrier system that achieves post-treatment effectiveness much like that of very large municipal or industrial plants.
One current example is Boeing’s choice of UV disinfection on its new 21st century airliner, the 787 Dreamliner, for POE potable water treatment. After a global search for best technologies, Boeing chose a smart system that is tied into the ’glass cockpit’ so pilots can monitor its effectiveness (see Figure 1).
The state of Vermont requires that its schools use UV disinfection at POE for potable water treatment. Mike Carey, Construction Engineer, Department of Environmental Conservation, State of Vermont, sees “a growing demand for UV systems for disinfection from people who were considering chlorine only for overall costs. It might be a bit more money to build and operate, but it does have the advantage of being very simple to operate, with builtin warnings and alarms, and no chemical testing for residuals.” Notwithstanding the dramatic growth of UV treatment for small potable water systems, the fastest segment growth is for advanced UV technology in reuse and wastewater treatment.
In much of the world, key issues are both quality of water and access to it; in scarce-water environments, treatment of water for reuse is common and that practice will soon be global. Australia, with a supportive regulatory regime, is a strong market for treatment of water captured from rainwater runoff and commercial processes, requiring treatment to acceptable standards (including microbiological) before reuse—typically for irrigation, agriculture or non-potable use (see Figure 2).
According to Phil Krasnostein, Technical Director of Nubian Systems, New South Wales, Australia, “The Australian water market is characterized by a concern for health and safety in domestic and commercial applications. At Nubian, we require the same level of comfort and performance if we’re treating one liter or one million liters a day. The products we choose fit perfectly into our strategy of delivering systems that provide both customers and regulators the comfort that their systems are intelligent and performing at the highest level.” In fact, McMaster University in Hamilton, Ontario is about to commission one of North America’s largest green-roof, rainwater capture systems that will treat runoff water to potable water standards using a multiplex system in the university’s drinking water distribution system.
UV POU disinfection of water that will be sprayed, (for example, in childrens’ spray [water] parks), in agricultural use and wash water, is now common—another reuse application seeing wide use in developed markets. Ontario and Quebec provinces in Canada have recently conducted tests to determine the best technology for treatment of wash water used in milking parlors in dairy production, prior to regulating that application.
Wastewater treatment has commonly incorporated UV as a final barrier in larger municipal applications for decades, but now smaller systems are used for residential and commercial secondary and tertiary treatment. Increasing numbers of jurisdictions are limiting septic systems’ leach fields and instead, requiring or accepting UV disinfection as a secondary barrier, especially if a proposed septic field is within a short distance of surface water (see Figure 3).
Quebec (Canada’s second most populous province) now requires UV disinfection on all septic tanks located near a surface water source. The leading North American residential and commercial wastewater treatment system manufacturer based in Quebec now offers UV as secondary disinfection on all of its systems to ensure, despite site variations, the safety of public health, as well as that of the environment. According to Roger Lacasse, Scientific and Technical Director of Premier Tech Aqua (PTA), “Field validation tests demonstrated the high reliability and efficiency of the self-cleaning systems using advanced technology. We observed that the treatment performance was maintained even in the most demanding conditions”.
China, beginning its twelfth five-year economic development plan, has targeted dramatic improvement of the quality of river water as a key objective, largely by treating wastewater prior to it being returned to the environment. UV is the best available technology for the final barrier in this treatment process and advanced systems that incorporate self-cleaning mechanisms, monitoring capability, and that limit operator exposure to treatment water are ideal solutions.
A preponderance of sources and observations indicate that water, one day soon, will not be an un-priced commodity—it will become, in fact, our most valued resource. And while experienced industry analysts and investors in water treatment technology and operations know only too well that this is an industry that moves relatively slowly (especially with respect to regulatory evolution and adoption of technology improvements), change is coming and the pace of change is accelerating. UV disinfection technology, and specifically today’s most advanced iterations of UV systems, incorporate benefits and advantages that make this ‘best-of-breed’ treatment available to smaller residential, commercial and institutional applications for potable, reuse and wastewater treatment.
About the author
Rick VanSant is a serial entrepreneur and angel investor, currently leading an early stage environmental technology company that develops and manufactures technically advanced UV water purification systems. Prior to UV Pure Technologies, he founded and/or led many public and private companies, including Moneysworth & Best Quality Shoe Repair and several hospitality, service and retail goods businesses.
About the company
UV Pure Technologies has been awarded Frost and Sullivan’s 2011 Best Practices Award as the leading water treatment technology, globally. The company develops and manufactures technically advanced UV water purification systems. There are currently over 10,000 systems installed in residential, commercial, industrial, public and municipal applications using up to one-MGD flowrates. An aerospace version of a UV Pure system has been chosen by Boeing to purify water on the new 787 Dreamliner.
About the products
UV Pure’s patented Crossfire Technology® is dramatically advantaged compared to conventional UV systems. Lamps are mounted in air surrounded by elliptical reflectors providing more effective deactivation of pathogens, and incorporating easy lamp changes and visual quartz inspection. Some models are self-cleaning and smart, with multiple sensors and on-board diagnostics, and engineered to be fail-safe and virtually maintenance free. Remote monitoring is available. UV Pure markets three product lines: Hallett® systems, NSF/ANSI 55 Class A-certified; Upstream™ systems, engineered to achieve the same performance standards as NSF 55 Class A for use where regulations do not require it, and for UVT levels as low as 50 percent; and the new Cactus™ systems, designed and priced for residential use. For more information visit www.uvpure.com. Pure safe water. Always.