Atmospheric & Environmental Chemistry
Atmospheric & Environmental Chemistry
Our Environment consists of a delicate balance between Air, Water and Land. It is not a true chemical equilibrium because biology (plants and animals) also play an important mediating role. Chemical studies of our Atmosphere, Oceans, Rivers, Snow-packs and Soil are therefore crucial to our understanding of how we can protect and improve our quality of life as we make more use of technological discovery. Phrases like Climate Change, the Ozone “Hole” and Green/Clean Chemistry are part of everyone’s vocabulary these days!
But to fully understand such processes and to predict the future, we have to develop our knowledge of the fundamental science that often falls in the category of “Physical Chemistry”.
For example, the 2007 Nobel Prize for Chemistry was awarded to the Physical Chemist, Professor Dr. Gerhard Ertl for his pioneering work in surface chemistry. He was instrumental in clarifying our ideas of what happens when gas-phase molecules hit solids and dynamic behaviour on surfaces.
His work has had a great impact on all our lives, even though you may never have heard of him before. In fact the scientific approach he made is important not only for understanding how ozone depletion in the polar stratosphere is accelerated by ice clouds but also for optimizing certain important industrial processes. The studies, which inspired many other scientists, has helped us to understand phenomena such as why iron rusts, how fuel cells function and how the catalytic converters in cars work.
There are also other applications: can you remember the Haber Process from your Chemistry course at School or College? (Hint: ammonia is produced after hydrogen and nitrogen react together on a surface. Can you balance the equation?).
It was not until the start of the twentieth century that this method was developed to harness the atmospheric abundance of nitrogen to create ammonia, which can then be oxidised to make the nitrates and nitrites essential for the production of some fertilizers. The actual mechanism, in which surfaces containing an ionic iron catalyst (Fe3+) and aluminium oxide (Al2O3) plus potassium oxide (K2O) are crucially involved, was understood much later, thanks to Ertl’s ideas and experiments.
Ammonia, which is an alkaline gas, when released to the atmosphere often reacts with acidic components such as sulfuric acid. And small (aerosol) particles of ammonium sulfate are thereby formed. Particulates actually have an important role to play in the atmosphere. Their optical scattering properties can lead to atmospheric warming or cooling depending on their composition. Much current work is being carried out to quantify these processes….for obvious climate reasons and LIDAR, a laser-based detection technique is foremost in these studies.
Particulate Matter (PM) can also have a deleterious effect on our health if breathed in!
The effects depend upon size, shape, and chemical/biochemical composition. These features are often controlled by their source (e.g. sea-salt spray, car exhausts/brakes/tyres, ships and aeroplanes, plants/trees/vegetables, domestic heating, construction industry) but surprisingly little is known about the connections between the ingredients, toxicology (cell experiments) and epidemiology (actual health outcomes). Much more needs to be known.
Research into all the areas described above is being carried out at UCC.
Check out the website for the Centre for Research into Atmospheric Chemistry.
|Prof. John Sodeau||Atmospheric Chemistry, Photochemistry & Spectroscopy.|
|Dr. Dean Venables
||Developing new spectroscopic approaches to detect trace gases, and then applying these tools to answer open questions in atmospheric chemistry.|
|Dr. John Wenger
||(i) Atmospheric Chemistry of volatile organic compounds; (ii) sources, composition and impacts of atmospheric particles.|