Victor Yu, MD, and Janet Stout, PhD, advance independent research to evaluate new methodologies, products, and approaches to diagnosis for the treatment and prevention of Legionnaires' disease and other infectious diseases through their academic affiliations with the University of Pittsburgh. Dr. Stout, is a research associate professor at the University of Pittsburgh Swanson School of Engineering in the Department of Civil and Environmental Engineering. Dr. Yu is professor of medicine in the School of Medicine and holds a secondary appointment in the Graduate School of Public Health.
Since 1995, they have mentored students from the fields of medicine, microbiology and engineering. Many of their students have presented research at national meetings and have been published in peer-reviewed journals, while others have become leaders in their respective fields with major research contributions.
Shift in Microbial Ecology in Hospital Hot Water System Treated with Monochloroamine
With the increase of Legionnaires' disease and the anticipated passage of a Legionella standard and other guidelines, many facilities are considering applying secondary disinfection to water distribution systems. However, little is known about how these additives impact the microbial ecology. Using next generation molecular sequencing methods-high throughput Illumina 16S rRNA region sequencing and 454 sequencing, SPL evaluated samples from a hospital's hot water system treated with onsite monochloramine. The results showed an immediate shift in the microbial population or microbiome. These techniques along with traditional culture, showed changes in Legionella, including rebound during a period of ineffective treatment. To understand the impact of different disinfection technologies on water systems more studies on the microbiome of the built environment, an emerging field or study, are needed.
Shift in the Microbial Ecology of a Hospital Hot Water System following the Introduction of an On-Site Monochloramine Disinfection System (Julianne L. Baron, Amit Vikram, Scott Duda, Janet E. Stout, Kyle Bibby. PLOS ONE Journal. July 2014.Vol 9 Issue 7.)
The NonChemical Treatment Device study was conducted by Dr. Stout, lead investigator Radisav Vidic, chair and William Kepler Whiteford Professor of civil and environmental engineering, and then-Pitt civil engineering graduate student Scott Duda. The specific objective of this investigation was to provide a controlled, independent, and scientific evaluation of several classes of non-chemical treatment devices (NCDs) for controlling biological activity in a model cooling tower system. The two-year study was funded by American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE).
Microbial growth in cooling water systems causes corrosion, decreases energy efficiency, and has the potential to cause human infection. Control of microbial growth in these systems is typically achieved with the use of chemical biocides. Recently, non-chemical water treatment methods have seen increased use as an alternative. However, few objective studies with an untreated system as a reference are available to verify the efficacy of these devices to control microbial growth in cooling towers.
Five NCDs were evaluated for efficacy in reducing planktonic (bulk water) and sessile (biofilm) microbial populations within a pilot-scale cooling system. The devices included magnetic, pulsed electric field, electrostatic, ultrasonic, and hydrodynamic cavitation:
- Magnetic Device (MD): RT-750-K Superior Water Conditioner®, Magnatech Corp, Fort Wayne, Ind.
- Pulsed Electric Field Device (PEFD): Dolphin Series 3000, Clearwater Systems Corp., Essex, CT
- Electrostatic Device (ED): FluidTron®, ElectroStatic Technologies, Inc., Kansas City, Kan.
- Ultrasonic Device (UD): Sonoxide® B02, Ashland Water Technologies, Wilmington, Del.
- Hyrodynamic Cavitation Device (HCD): VRTX-10, VRTX Technologies, Schertx, Texas
Biological Control in Cooling Water Systems Using Non-Chemical Treatment Devices, ASHRAE 1361RP
Read the study
Biological control in cooling water systems using nonchemical treatment devices. Scott Duda, Janet E. Stout & Radisav Vidic. HVAC&R Research, 17:5, 872-89.
Dr. Janet E. Stout gives in-depth interview to Matt Nelson of HVAC 360 on nonchemical treatment devices study.