UV News

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UV Articles 2013

March, 2013: Ultraviolet Germicidal Irradiation in Building Air-Handling Systems: State-of-the-Art
IUVA News

The most recent issue of IUVA News, published by the International Ultraviolet Association, includes an article from Shelly L. Miller and Julia Luongo from the University of Colorado Boulder. The article, titled Ultraviolet Germicidal Irradiation in Building Air-Handling Systems: State-of-the-Art, discusses the benefits of using germicidal UV in the air conditioning systems to reduce energy consumption and realize energy savings. The authors point out that the buildings are responsible for about 40% of the total energy consumption in the USA with more than half of that going to heating, ventilating and cooling the indoor air.

One of the factors for reduced heat exchange efficiencies and reduced air flows through heating and cooling equipment is the bio-film forming on the heat exchangers. The authors cite research according to which various microorganisms growing inside the air handlers often contribute to building-related diseases in occupants in addition to increased energy consumption.

Even though regular cleaning and maintenance of the air handlers is recommended it is not usually done as often as needed and the chemical disinfectants used to reduce microbial contamination can be dangerous to the service technicians as well as the occupants of the buildings. Some harsh chemicals can also shorten the life of the AC equipment.

The authors assert that there is enough background information and regulatory requirements to justify the use of germicidal ultraviolet technology for keeping the air conditioning systems running at design capacity. This is achieved through reduced bio-fouling and also results in lower maintenance and energy costs and better indoor environment. The portion of the GSA Facilities Standards for the Public Buildings specifying the use of germicidal UV downstream of cooling coils is quoted. It is also shown that deploying germicidal UV systems for cooling coils can count toward LEED credits, specifically in the "Innovation by Design" area.

The article concludes that more experimental research is needed in real buildings as the UVGI technology is increasingly more widely used for energy and maintenance savings and improvement of the indoor environments. Germicidal UV should prove to be an excellent tool for achieving energy savings for many buildings containing heating, ventilation, air conditioning and refrigeration systems.

Complete article here: Ultraviolet Germicidal Irradiation in Building Air-Handling Systems: State-of-the-Art

March 26, 2013: Crystal IS claims record performance from UV-C LEDs
ledsmagazine.com by Tm Whitaker, a Contributing Editor at LEDs Magazine

Short-wavelength UV LEDs with higher output are likely to be used increasingly in applications such as disinfecting water, sterilizing surfaces, and spectroscopy.

Crystal IS, Inc., a manufacturer of ultraviolet LEDs for monitoring, purification, and disinfection applications, has reported a UV-C LED with an optical output of 65mW at 260 nm when operated in continuous mode.
UV-C refers to ultraviolet light with wavelengths of 200-280 nm. Light in the UV-C wavelength range can be used for disinfecting water, sterilizing surfaces, destroying harmful micro-organisms in food products and in air, and for spectroscopy applications.

Leo Schowalter, founder and CTO of Cystal IS, described the latest results as “a technological milestone in the continued development of brighter, more efficient and reliable UV-C LEDs. By employing die thinning and encapsulation techniques, we were able to increase the photon extraction efficiency to over 15%,” he said.

Details were recently published in Applied Physics Express. “By fabricating our LEDs on our home-grown aluminum nitride (AlN) substrates, we continue to set the pace of what is possible for the combination of highest efficiencies and longest lifetimes in the 250-280 nm wavelength range, far surpassing diodes fabricated on sapphire,” added Schowalter.

Yole Développement estimates that the UV-C lamp market was nearly $200 million in 2012, with lamps being replaced increasingly by UV LEDs.

"Our products will address some of the most pressing health concerns of our time,” said Therese Jordan, senior VP of business development. “We are seeing demand in both water and air for the disinfection and quality-monitoring aspects of UV-C. Similarly, spectroscopic instruments are also taking advantage of the high light output available in a UV-C LED.

“Unlike UV lamps, UV-C LEDs are mercury-free, compact, rugged and robust, lending themselves to an array of designs. They hold the promise of long life and environmentally friendly end-of-life disposal.”

March 19, 2013: Portland Water District installs ultraviolet micro-organism killer
therepublic.com

The Portland area's drinking is now safer.

Portland Water District officials on Monday announced that a 5.5-ton ultraviolet disinfection unit has been installed in an unused underground well at the district's Standish facility.

It is part of a $12.8 million project designed to eliminate pathogens from the public drinking water supply.

The 14-foot long unit contains 84 ultraviolet lamps and can treat 52 million gallons of water a day. The light penetrates micro-organisms and kills them. A second backup UV unit will be installed later this year.

District spokeswoman Michelle Clements tells The Portland Press Herald the impact for rate payers is expected to be "minimal."

March 19, 2013: Study Shows Effectiveness of Ultraviolet Light in Hospital Infection Control
infectioncontroltoday.com

Research presented at IDWeek 2012 showed that a specific spectrum of ultraviolet light killed certain drug-resistant bacteria on the door handles, bedside tables and other surfaces of hospital rooms, suggesting a possible future weapon in the battle to reduce hospital-associated infections.

Researchers at Duke University Medical Center and the University of North Carolina Hospital System used short-wave ultraviolet radiation (UV-C) to nearly eliminate Acinetobacter, Clostridium difficile or vancomycin-resistant enterococci (VRE) in more than 50 patient rooms at the two medical facilities.

“We’re learning more and more about how much the hospital environment contributes to the spread of these organisms,” says lead researcher Deverick J. Anderson, MD, an assistant professor of medicine at Duke and co-director of the Duke Infection Control Outreach Network. Given previous findings by the University of North Carolina team that UV-C is effective at decreasing methicillin-resistant Staphylococcus aureus(MRSA) in hospital rooms, he believes that the new study lays critical groundwork.

“We have a solid foundation to show that this approach succeeds in both experimental and real-world conditions,” Anderson adds. “Now it’s time to see if we can demonstrate that it indeed decreases the rate of infections among patients.”

His group’s work is among the significant research being discussed at the inaugural IDWeek meeting, which was held Oct. 17-21 in San Diego. With the theme Advancing Science, Improving Care, IDWeek features the latest science and bench-to-bedside approaches in prevention, diagnosis, treatment, and epidemiology of infectious diseases, including HIV, across the lifespan. More than 1,500 abstracts from scientists in this country and internationally will be highlighted over the conference’s five days.

“Healthcare-associated infections are linked with significant morbidity and mortality,” says Liise-anne Pirofski, MD, an IDWeek chair for the Infectious Diseases Society of America. “Although there are multiple sources for these infections, the hospital environment itself can play an important role. The findings of this study suggest that UV light could hold promise for eliminating bacteria from hospital rooms and reducing the risk of infection with these difficult bacterial pathogens in the healthcare environment. That would be a result to benefit us all.”

UV-C, which is harmful to microorganisms, has been used for decades in food, air and water purification and to sterilize equipment in laboratory settings. This study demonstrates that its medical application may offer new strategies for reducing the estimated 1.7 million hospital-associated infections that occur annually in the United States. The cost of treating these infections, often involving increasingly antibiotic-resistant bacteria, ranges from an estimated $4.5 billion to as much as $11 billion.

In their study, the Duke and University of North Carolina researchers questioned whether UV-C could be utilized to eliminate three of the most problematic germs and improve the cleanliness of patient rooms. Given the tough economics of healthcare today, hospitals’ environmental services are under pressure to turn rooms over quickly, and many surfaces can get missed by even the most diligent crews.

The study focused on general-medical and intensive-care units of the two medical centers and identified patients with infections from the targeted bacteria. Clostridium difficile, or C. diff as it is commonly known, can trigger serious intestinal conditions. Acinetobacter can cause pneumonia and serious blood, wound and urinary tract infections. VRE most frequently infects the urinary tract, bloodstream, wounds or catheter sites. Each bacterium can survive for prolonged periods on surfaces.

After the patients were discharged, the researchers obtained multiple cultures from each of five specific locations in the hospital rooms and bathrooms – high-touch areas that included bed rails, remote controls and toilets. A special machine with eight UV bulbs mounted on a central column was then positioned strategically in each room and turned on for as long as 45 minutes to eradicate both vegetative bacteria and bacterial spores. Fifteen more cultures were taken from the same locations in every room, and the pre- and post-treatment bacteria counts were compared.

The numbers of bacterial colony-forming units (CFUs) fell precipitously. Fifty-two CFUs of Acinetobacter were seen before irradiation, but only 1 CFU afterward – down 98.1 percent. As for VRE, the proportion decrease was nearly the same – 719 CFUs before and 15 after, a 97.9 percent drop.

The culturing initially was not sensitive enough to isolate C. diff, but improved techniques allowed the researchers to do further testing and the results in the UV-C treated rooms were just as dramatic.

“We would never propose that UV light be the only form of room cleaning, but in an era of increasing antibiotic resistance, it could become an important addition to hospitals’ arsenal,” Anderson says.

February 8, 2013: Karl Linden, President Elect of International Ultraviolet Association Leads Research Team That Won Gates Foundation Grant
marketwire.com / Source: International Ultraviolet Association

Dr. Karl Linden, Professor of Environmental Engineering at University of Colorado Boulder, leads a research team that was recently awarded a grant from the Bill and Melinda Gates Foundation for $780,000 for the Reinvent the Toilet Challenge (RTTC). The grant challenges scientists and engineers to design a toilet that uses little or no water, is energy and cost efficient and converts waste into a useful product. Karl Linden's team proposed a design idea that utilizes solar energy to convert waste into biochar, a product that can be used as fertilizer.

Dr. Linden is the President Elect of the International Ultraviolet Association (IUVA), a position he will assume in July of this year. Many of the scientists and engineers who are members of the IUVA design and maintain systems that use ultraviolet light to disinfect water, wastewater and air. These systems are in use across the United States and globally.

Linden will be leading a team of graduate students and collaborating with two other University of Colorado professors: Environmental Engineering Professor R. Scott Summers and Chemical and Biological Engineering Professor Al Weimer. Josh Kearns, a PhD candidate, has been using a biochar process to purify drinking water in developing countries. Kearns will provide his expertise for the RTTC project.

"This project is also very student-driven," said Dr. Linden in a press release issued by University of Colorado. "Students with classroom and field-based experiences in our Engineering for Developing Communities program have provided some excellent ideas, expertise and enthusiasm to make this project possible."

Paul Swain, President of IUVA, has been a colleague of Linden's for some time. "Once again, Karl Linden is at the forefront of critical issues impacting public health and the environment worldwide," says Swain. "The IUVA is fortunate to have a true leader in our field as our next International President," he added.

IUVA's mission is to advance the science, engineering and applications of ultraviolet water disinfection and air pollutant technologies to enhance the quality of human life and to protect the environment. Founded in 1999, it is a 501(c)3 educational association of more than 500 members in 35 countries. IUVA is recognized as the leading knowledge base and voice for UV technologies through its varied conferences and programs. Visit IUVA.org.

January 15, 2013: UV Experience for Inactivating Cryptosporidium in Surface Water Plants
Wateronline.com / Authors: Keith Bircher, G. Elliott Whitby and John Platz

Regulatory Background - The disinfection of pathogenic microbes in drinking water has been successful over the last century largely due to the use of chlorination. However, research conducted in the 1970’s revealed that by-products formed during the chlorination process are potentially carcinogenic and that there is a direct correlation between the concentration of chlorination by-products and the probability of certain cancers and other health problems. Following these discoveries, drinking water regulators have struggled within the confines of technological and economic limitations to find a balance between the benefits of chlorination and its harmful side effects.

In the U.S.A., the Surface Water Treatment Rule (SWTR) of 1989 mandates inactivation levels for Giardia cysts and enteric viruses, and also sets treatment standards for Trihalomethanes (THM’s, a common disinfection by-product). The SWTR provides guidance to drinking water facilities through “CT” tables that prescribe the inactivation efficacy of various processes under varying water quality conditions. By following this guidance, most water treatment plants were able to provide an adequate degree of disinfection while not compromising their Disinfection By-Product (DBP) limits and without requiring major changes to their plants. However, continuing DBP health effect research indicated that even the DBP standards required in the SWTR of 1989 produced an unacceptable level of risk and the SWTR was amended in 1996 to lower the level of DBP’s. The new DBP standards have caused many plants to fall out of compliance, requiring either extensive plant modifications or new disinfection strategies. In addition, a major outbreak of cryptosporidiosis in Milwaukee in 1993, and other minor cryptosporidiosis and giardiasis outbreaks caused regulators to create a removal requirement for Cryptosporidium oocysts in the 1998 Interim Enhanced Surface Water Treatment Rule (IESWTR) and a further treatment requirement in the Long Term 2 Enhanced Surface Water Treatment Rule (LT2ESWTR) which was promulgated in December 2005. The LT2ESWTR includes a treatment requirement for Cryptosporidium and many surface water plants will fall out of compliance due to the very poor ability of chlorination to inactivate Cryptosporidium. A void was created for water treatment technologies that will inactivate protozoa and viruses, not create DBPs, and are economically feasible. One technology that meets all three criteria is ultraviolet (UV) disinfection.

Ultraviolet light has long been known to be effective for the inactivation of viruses and bacteria in drinking water and guidelines for the disinfection of viruses with UV light exist in the U.S. EPA Alternative Disinfectants and Oxidants Guidance Manual. However prior to 1998, UV was widely considered to be ineffective at economically feasible UV doses for encysted protozoa (like Giardia and Cryptosporidium), as it was thought that UV would have to rupture the cyst membrane wall. Since Giardia was the controlling microbe for the determination of the dose of chlorine and since the UV dose required for Giardia was believed to be completely too high to be considered, no reductions in chlorine usage could be gained by using UV. As a result, UV disinfection was not used for drinking water in North America; however it has been and continues to be used extensively in Europe for groundwater.

Breakthrough research conducted by Calgon Carbon Corporation in 1997 and 1998 proved that UV disinfection is, in fact, very effective for inactivating Cryptosporidium and Giardia at low UV doses. Subsequent to Calgon Carbon’s research, the U.S. EPA created a UV working group to report to the Federal Advisory Committee (FACA) on issues and costs related to UV disinfection, resulting in the development of the UV Disinfection Guidance Manual (UVDGM) by the U.S. EPA and the promulgation of the LT2ESWTR. Many utilities are now using or are considering UV disinfection in their plants as either an additional barrier for protozoa disinfection or to get disinfection credits for Cryptosporidium and/or Giardia and to lower chlorine doses to meet the 1998 DBP standards.

Read complete article: UV Experience for Inactivating Cryptosporidium in Surface Water Plants /PDF/