Microbial Carbon Dioxide Sequestration Explained
One of the suggested methods for sequestration of carbon dioxide is to compress the gas and pump it into an underground saline aquifer. There are numerous of these aquifers about, some of them deep underground and capable of holding huge amounts of compressed CO2.
Up until now the effect of the injected CO2 on the microbes present in the saline solution was unknown, however scientist have been developing models and conducting experiments on an aquifer in Frio Ridge, Texas.
The Pressurized Carbon Dioxide was pumped into the aquifer, 5741 feet underground where the CO2 plume mixed with the brine solution as it travelled downwards. Samples were collected from various locations, then filtered and any living or dead creatures extracted and a DNA analysis carried out to determine the extent of their diversity. These results will assist in determining the capacity of the underground aquifer microbe ecosystem to store CO2.
These microbes, which despite the harsh brine water continue to settle and continue to breed, will again be collected and an attempt to cultivate them will be made.
If successful, the cultivated microbes will be subjected to a high pressure in the lab; and a strain of microbe resistant to the high pressure CO2 developed and studied to see how they would behave under an actual CO2 sequestration conditions.
Finally, some microbes excrete a fine biofilm, somewhat like the film which appears on our teeth if we don’t clean them.
This microbial biofilm will gradually build up within the aquifer and could eventually assist in the sealing of the aquifer against leaching or leaking of the stored CO2.
Reference Web: Saline Aquifers - Sequestration of CO2 Underground