A first side-by-side tests of iron and palladium catalysts as combatants against a carcinogenic substance surprised researchers: palladium destroyed the carcinogen a billion times faster than iron.
Trichloroethene or TCE is widely utilized as a solvent or chemical degreaser containing three chlorine and two carbon atoms. Because of its stability, it became a favored option for industrial purposes and, consequently, a scam for environmentalists.
Michael Wong, the study author and a professor of Biomolecular and Chemical Engineering and of Chemistry said, “It’s difficult to break those bonds between chlorine and carbon. Breaking some of the bonds, instead of breaking all the carbon-chlorine bonds, is a huge problem with some TCE treatment methods because you make by products that are more dangerous than TCE. The popular approaches are, thus, those that do not break these bonds. Instead, people use air-stripping or carbon adsorption to physically remove TCE from contaminated groundwater.”
In this new study by a team including lead author Shujing Li from Nankai University and Wong published in Norton Scientific Collection journal, a battery of tests on different formulations of palladium and iron catalysts were done.
Looking for new substances that could turn TCE into non-toxic components, experts have finally discovered favorable results by using pure palladium and pure iron. Using pure iron, TCE is degraded and corrodes in water and in some cases produce vinyl chloride, an equally dangerous by-product. Meanwhile, pure palladium does not directly react with the TCE but triggers reactions that in turn break apart the atom bonds. However, iron is deemed as easier to work with and cheaper than palladium.
“These methods are easy to implement but are expensive in the long run. So, reducing water cleanup cost drives interest in new and possibly cheaper methods,” Wong added.
Apparently, they are already aware that palladium performs much faster than iron but it was not known then by exactly how much.
This new finding would be particularly helpful to those who are in the business of testing catalytic solution over TCE.