The water crisis in Flint, Michigan, brought much-needed attention to the problem of potentially toxic metals being released from drinking water distribution pipes when water chemistry changes. Now, researchers reporting in ACS’ Environmental Science & Technology have investigated how hexavalent chromium, known as Cr(VI), can form in drinking water when corroded cast iron pipes interact with residual disinfectant. Their findings could suggest new strategies to control Cr(VI) formation in the water supply.
The metal chromium, known as Cr(0), is found in cast iron alloy, which is the most widely used plumbing material in water distribution systems. As pipes corrode, a buildup of deposits, known as scale, forms on the pipes’ inner walls. Trace chemicals in water can react with scale, forming new compounds that could be released into the water. Some of these compounds contain Cr(VI), which, at high doses, can cause lung cancer, liver damage, reproductive issues and developmental
Chromium steel—similar to what we know today as tool steel—was first made in Persia, nearly a millennium earlier than experts previously thought, according to a new study led by UCL researchers.
The discovery, published in the Journal of Archaeological Science, was made with the aid of a number of medieval Persian manuscripts, which led the researchers to an archaeological site in Chahak, southern Iran.
The findings are significant given that material scientists, historians and archaeologists have long considered that chromium steel was a 20th century innovation.
Dr. Rahil Alipour (UCL Archaeology), lead author on the study, said: “Our research provides the first evidence of the deliberate addition of a chromium mineral within steel production. We believe this was a Persian phenomenon.
“This research not only delivers the earliest known evidence for the production of chromium steel dating back as early