Washington: In a research aimed at improving the quality of water in space, University of Utah chemists have developed a two-minute water quality monitoring method that just started six months of tests aboard the International Space Station (ISS).
“Now they bring water back on the space shuttle and analyze it on the ground. The problem is there is a big delay. You’d like to be able to maintain iodine or silver (disinfectant) levels in real time with an onboard monitor,” said Marc Porter, a University of Utah professor of chemistry and chemical engineering.
The new method involves sampling space station or space shuttle galley water with syringes, forcing the water through a chemical-imbued disk-shaped membrane, and then reading the color of the membrane with a commercially available, handheld color sensor normally used to measure the color and glossiness of automobile paint.
The sensor detects if the drinking water contains enough iodine (used on U.S. spacecraft) or silver (used by the Russians) to kill any microbes.
The International Space Station has both kinds of water purification systems.
“Our focus was to develop a small, simple, low-cost testing system that uses a handheld device, doesn`t consume materials or generate waste, takes minimal astronaut time, is safe and works in microgravity,” said Porter.
As a spinoff, the test is being modified so it can quickly check water for the level of arsenic – a natural pollutant in places like Bangladesh and the U.S. Southwest and Northeast – and it can be adapted to quickly, inexpensively test for other pollutants.
“It is a general method. It could be used on the ground for testing all kinds of water contaminants such as arsenic, chromium, cadmium, nickel and other heavy metals,” said Lorraine Siperko, a senior research scientist in Porter’s laboratory.
The method is easy to use and much cheaper than existing tests, according to Porter.
The water-monitoring system fits in a pack the size of a small ice chest. It was launched on August 28 on space shuttle Discovery bound for the International Space Station.
During the past decade, the water quality monitoring method was developed and tested during about two dozen low-gravity flights on NASA’s “vomit comet” research aircraft such as the KC-135 and C-9, which took off from Ellington Air Force Base in Texas.
“Now, the experiment is in space for the first time,” Siperko said.
On the space station, “once per month they will check the water for iodine and silver. That data will be downloaded and relayed back to Earth, to Johnson Space Center in Texas,” she added.