Monthly Archives: August 2014

Carbon sequestration in subsurface rock

Carbon sequestration by injection of supercritical carbon dioxide (CO2) into rocks is a viable option to combat global warming and the rise in CO2 in the atmosphere. Supercritical CO2 behaves as a fluid under high pressure and can be injected into the subsurface using wells drilled deep into the Earth.  The carbon dioxide used for injection would ideally be waste from a manufacturing plant that can be captured and put back into the Earth instead of released into the atmosphere as CO2.  When supercritical CO2 is injected into rock layers, it can form new rocks called carbonates that will trap the CO2 underground.  This is important because the global rise in CO2 levels is contributing to ocean acidification, sea level rise, loss of habitat for arctic and antarctic life, loss of coral reefs, and global warming.
I am currently working on a side project that will determine how the biosphere will be affected by the injection of supercritical CO2.  We have core material from the well and a fellow student ground up the rock from inside the core and extracted all the DNA so we can build a phylogenetic, or family, tree to see what organisms are there before the injection.  We will also have a look at the community of microorganisms present after a simulated injection of supercritical CO2 and determined how it has changed.  This information is critical to the success of these types of endeavors for a number of reasons, one being because we do not want to increase organisms that make methane from the CO2.  Methane is even more potent as a greenhouse gas than CO2.

Today I am finishing up the procedure to get the DNA ready for sequencing.  We are using Illumina sequencing which will give us millions of sequences to work with.  Once we have the sequences, we can compare them to known organisms and determine how related they are using algorithms.  We can also determine the percent composition of each organism and diversity of the community by determining how abundant each organism is in the community and how many organisms there are.  Well, it’s about time for me to go finish up and send the samples off for sequencing!  Wish me luck.

Amy

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