As if Matt Damon's character in "The Martian" wasn't worried enough that the potatoes he grew on the red planet might be contaminated with perchlorate. But now, a new study led by researchers at the University of California, Riverside, has found a relatively simple catalyst that can remove these chemicals and also help reduce water and soil pollution on Earth.
Containing one chlorine atom and four oxygen atoms, perchlorate is a powerful oxidant most commonly used in rocket fuel, fireworks and torches. They are also by-products of cleaning chemicals and herbicides, so they often become contaminants in soil and water. High levels of perchlorate can lead to thyroid problems and other potential health effects.
But perchlorates aren't just a problem on Earth -- they've been found in large quantities in Martian soil, which could make it difficult for future settlers to grow their own food. Currently, contaminants can be removed by several methods, but they are usually difficult and expensive.
In the new study, researchers at the University of California, Riverside, have found an even simpler way to reduce perchlorate in water, all in one step, without the need for high temperature or pressure. The catalyst for this process is known to consist of three fairly common components: a fertilizer called sodium molybdate, an organic ligand called bipyridine, and palladium. Together, with the help of hydrogen, these three components quickly and almost completely break down the perchlorate.
"This catalyst is more active than any other chemical catalyst reported to date, reducing more than 99.99% of the perchlorate to chloride regardless of the initial concentration of the perchlorate," noted Changxun Ren, one of the authors of the study.
The team says the new catalyst works well in a wide range of possible concentrations of contaminants -- from less than 1 milligram per liter to 10 grams per liter. That means it could be used to treat contaminated water on Earth or one day help the first Martians grow safe food or even generate oxygen.
Jinyonog Liu, one of the authors of the study, said: "A convenient catalytic reduction system could help extract oxygen from perchlorate in the Martian soil when the catalysts are combined with other processes."