What exactly did I come to Iceland for? Besides the scenery...

As many have asked about how my PhD is going thus far, here is a summary of the project (as it stands now) and a status update:

Last fall I applied for a position under the title: Does CO2 injection cause toxic metal plumes? The description roughly fit my background so I applied on a whim and very happily was accepted! Paperwork to move to Iceland took about 3 months, but soon enough came my arrival to Reykjavik. 

Bought a used jeep - really need 4WD for all the off-roading (and bad roads), Photo by Becca Neely

 As with any new position, things started off slowly and it took awhile to get settled in (like setting up a bank account and buying a car). I was immediately given a desk in an office for 3 people, though for the moment have it all to myself and have bought some plants to keep me company.

Plants to fill up my large desk

Askja  in March - Earth Science building I work in

There is quite an active graduate student population here, with associations for the geoscientists and biologists organizing events throughout the school year. At least 1/2 of the graduates are actually foreign...well European, but then again many of those are German-speaking or from the UK/English-speaking. There are also quite a number of lectures during the week of a variety of topics from those at the university and those visiting. Every Friday, except during the summer, is "Friday Lunch" at 11:30. This is quite anticipated as the graduate students, professors and researchers rotate to bring a lovely lunch to fill the meeting room table up with bread, fruits, cake, spreads, juice and so on. In addition, on most Wednesdays, my supervisor and his PhD/Post-Doc students - aka the Bambi group - meet and chat over lunch. Those of us situated at the university are actually all female, with one male having just received his PhD in May and the other living in northern Iceland working on his papers.

My rather large lab space

Anyways, the main focus of my PhD research right now is a 2.3 meter high pressure column flow reactor, where I am to simulate CO2 injection into basalt and assess the risk of toxic metal mobility. The previous PhD student, who is now a Post-Doc, had designed the setup and completed some experiments, and then took it apart this past December. She has since been teaching me the ins and outs of the column experiment, cleaning it, putting the pieces back together and testing all the parts out in order to get some more experiments up and running again.

Column when taken apart

The column itself is composed of 7 titanium compartments each with their own sampling port. There are two additional caps with ports as well for the inlet and outlet tubes. The idea is that two pumps are connected to a mixing chamber where CO2 and H2O are mixed together at certain flow rates, then this mixture enters the column from the bottom and flows upward (reason being to remove any preferential flow due to gravity) interacting with the basalt.

Mixing chamber and piston pump

Then it gets all confusing...as there are the 7 sampling tubes from each compartment which are connected to a main sampling device in addition to the outlet tube. These tubings and sampling device are also connected to 2 back pressure gauges to insure that a high pressure is maintained throughout the column. I am still unsure of the whole sampling device setup, hopefully when I put it back together I will understand it more! 

Column put together with all tubings, back pressure gauges within the wooden box on the left

Closer look at the compartment sampling ports each with their own filters and valves, on the left is where I am just all confused, still to learn this aspect of sampling from the column!

Never used syringe pump

One big difference between the old experimental setup and the new setup will actually be the use of a syringe pump (instead of a piston pump) for CO2 that is more precise and also allows for a lower flow rate. This will result in a longer residence time for the CO2-H2O mixture in the column when flowing from the bottom to the top...before it was 8 hours, now we are hoping for 1 month.

As the column is now together and water pumped in (the volume of the column is about 4.5 L), I am now checking for leaks under high pressure and double checking the flow rate of the H2O piston pump so that I will have a nice flow rate ratio with the new syringe pump, which also still needs to be tried out and tested (never been used yet, eek!).

Gold-coated basaltic glass samples for the SEM

Meanwhile...I have been looking at the basalt that used to be in the column and got some preliminary insight using an SEM (scanning electron microscope) at the university, this microscope helps to produce images of the surface of individual particles so I can assess whether there has been alterations after interacting with CO2-charged waters. I am now preparing to use the SEM again (albeit a different one at another institute) to get a better idea of the chemical composition of the basalt. The results will be presented at a conference our university is holding next month, which I am quite looking forward to - also as it will be my first "science" conference ^_^

Agate disk mill

 

Besides the SEM work, I am continuously trying to prepare new material for the next set of column experiments. The material is basaltic glass that was sampled from a mountain near the Blue Lagoon. It is crushed, ground and sieved to the right particle size and then finally cleaned of the ultra-fine particles. Currently I am making use of an agate disk mill, think of it as a machine-run mortar and pestle. Unfortunately, as it is quite old (main parts from 1969), its belt has broken and we keep temporarily fixing it with rubber rings that just stretch when too warm from continuous use. As it is summer and lots of people are off on holiday, a more lasting solution will not be found until August/September. Despite this, I am slowly but surely grinding and sieving in order to obtain 8 kg of material.

Bucket on right to be completely grinded, correct particle size sieved into bucket on left (eventually filled...), bucket in middle will be re-sieved and re-grinded

Lastly, in the background of all the other background work to the column, I am using a geochemical modelling program called PHREEQC to model the column experiments and its parameters. This will allow me to get a general overview of the reactions that I would expect to occur before running the actual experiment. Right now I am double-checking all the parameters used for previous model runs and then will run the model again in preparation for the new experiments.

Hm... anything else besides this...well trips around Iceland of course!!! But that shall have to wait, so sit tight and my next post shall be about my trips to places like West Fjords, the Golden Circle and Snaefellsnes peninsula! This weekend I shall actually be off on another trip to see these famous East Fjords everyone here keeps going on about :P

Hiking up Vifilfell, 30 min drive from Reykjavik, Photo by Mona Dragosics