We have developed a new technique for measuring mercury emissions.
Mercury is a deadly neurotoxin that affects the brains of 60,000 babies a year in the United States alone. It is estimated that industrial pollution, particularly from the burning of coal for the production of electricity, introduces 2400 tons of mercury into the air every year. The substance enters the aquatic food chain, where it spreads to humans who eat contaminated fish. Pregnant women and young children are especially vulnerable, and pre-natal mercury exposure can cause learning and developmental disorders in children.
Existing methods of measuring mercury at the sources of pollution are unreliable. CAMIC Director and Lead Investigator, Professor Suresh Bhargava explains, “Industrial chimneys release a complex concoction of volatile organic compounds, ammonia and water vapour, which interfere with the monitoring systems.”
The first step of controlling any kind of toxin is to be able to measure it. “In order to better understand mercury emission sources, continuous emission monitors located at strategic points within a given process are a must,” Professor Bhargava said.
A research team developed a new sensor for measuring mercury in the atmosphere. The sensor uses a surface of gold that has been altered using an electrochemical process to produce hundreds of tiny spikes, each one 1000 times thinner than a human hair.
Once exposed to a sample of gases, the sensor uses existing technologies such as quartz crystal microbalances to determine the level of mercury.
“We’ve known since ancient times that gold attracts mercury, but a regular gold surface doesn’t absorb much vapour, making measurements inconsistent,” Professor Bhargava said. “Our nanoengineered gold surfaces are 80 percent more accurate than non-modified surfaces.”
Laboratory and field trials have demonstrated the new senor to be accurate over many months and across a range of extreme temperatures. The research team has received a new Australian research council linkage grant to develop a stand-alone mercury sensing device for deployment at an industry partner’s Australian refinery.