Water is highly prized in the unforgiving realm of space travel and habitation. Ample water reserves for drinking, food preparation, and bathing would take up an inordinate amount of storage space and infrastructure, which is always at a premium on a vessel or station. Water rationing and recycling are thus an essential part of daily life and operations on the space shuttles and International Space Station (ISS). The Environmental Control and Life Support System (ECLSS), under continuing development at Marshall Space Flight Center in Alabama, helps astronauts use and reuse their supplies of water.
The ECLSS Water Recycling System (WRS), developed at Marshall, reclaims wastewater from humans and lab animals in the form of breath condensate, urine, hygiene, and washing, and other wastewater streams. On Earth, biological wastewater is physically filtered by granular soil and purified as microbes in the soil break down urea, converting it to a form that plants can absorb and use to build new tissue. Wastewater also evaporates and returns as fresh rainwater — a natural form of distillation. WRS water purification machines on the ISS mimic these processes, though without microbes or the scale of these processes.
Umpqua Research Company of Myrtle Creek, OR — supplier of the bacterial filters used in the life support backpacks worn by space-walking astronauts — received a number of Small Business Innovation Research (SBIR) contracts from Johnson Space Center to develop air and water purification technologies for human missions in space. Umpqua has also provided the only space-certified and approved-for-flight water purification system, which has flown on all shuttle missions since 1990.
How it Works
To prevent back-contamination of a drinking water supply by microorganisms, Umpqua developed the microbial check valve, consisting of a flow-through cartridge containing iodinated ion exchange resin. In addition to the microbial contact kill, the resin was found to impart a biocidal residual elemental iodine concentration to the water. Umpqua’s valve and resin system was adopted by NASA as the preferred means of disinfecting drinking water aboard U.S. spacecraft, and canisters are now used on space shuttle missions, the ISS, and for ground-based testing of closed life support technology. Iodine was selected by NASA as the disinfectant of choice because of its lower vapor pressure and reduced propensity for formation of disinfection byproducts compared to chlorine or bromine.
MRLB International of Fergus Falls, MN, used Umpqua’s water purification technology in the design of the DentaPure waterline purification cartridge. The cartridge incorporated a resin technology developed by private sector commercialization of Umpqua’s system developed under NASA contract. DentaPure was designed to clean and decontaminate water as a link between filter and high-speed dental tools and other instruments, and offers easy installation on all modern dental unit waterlines with weekly replacement cycles. The product, like its NASA forebear, furnished disinfected water and maintained water purity even with “suckback,” an effect caused by imperfect antiretraction valves in dental instruments, which draws blood, saliva, and other materials from a patient’s mouth into the waterline.
MRLB has continued to use the research conducted by Umpqua to further develop and refine its DentaPure inline filters. Various models now address a variety of needs, and are used in dental offices and schools across the country. MRLB has paid particular attention to extending the life in lower water-usage units — products that before touted a service/replacement interval of 7 days now require changing once every 40 to 365 days.
Currently, the only waterline system recognized by the U.S. Food and Drug Administration (FDA) as a medical device that meets all known standards, and by the U.S. Environmental Protection Agency (EPA) as an antimicrobial device, DentaPure has also been tested and utilized by the U.S. Air Force and dental schools in the United States and Europe.
Where it Stands
DentaPure is currently the number-one product for constant chemical treatment applications in dentistry. Turning to the future, DentaPure will look at remote site water purification for continuous use, providing yet longer lasting devices, and increasing product recycling.
For more information on the DentaPure water purification system, visit http://info.hotims.com/22930-156 .