Tuesday, August 28, 2012

Corine Samaras's Research Experiences for Undergraduates - Summer 2012 - Part 3

Hello Again! 

My time in the Huettel lab has come to an end, but I am still working on analyzing my results! I enjoyed my time in the lab very much and learned so much in the process. I was introduced to the world of research, as I put the idea of my experiment in action.

To better explain my research, we broke it in to three different experiments. Experiment 1 assessed oxygen consumption of weathered MC252 crude oil exposed to a water flow of 18 ml h-1 or 1.8 cm h-1. Four columns contained seawater only, the other four 100 ml of weathered MC252 crude oil applied to the surface of small glass rods mounted in the columns and exposing the oil to the water flow (experimental treatment).

Experiment 2 assessed oxygen consumption by a known volume of weathered crude oil buried in saturated sand and exposed to a defined water flow. The columns containing live sands (controls) or natural live sands mixed with 100 ┬Ál of weathered MC252 crude oil (experimental treatment) were percolated at the same rate as used in Exp. 1 with filtered sea water (18 ml h-1). As in Exp. 1, differences in oxygen and DIC between in-and outflow and between control and treatment columns were used to determine the effect of oil on oxygen consumption and DIC production in the percolated sands.

Experiment 3 repeated Exp. 2 but at a doubled flow velocity (36 ml h-1). We took all samples at equivalent time intervals as used in Exp. 2 in order to have comparable data.

Our experiments show that buried oil is aerobically degraded in flushed marine sands. Higher pore water velocities enhance the degradation process of oil. This supports previous research findings that the habitats exposed to the greatest wave activity contained the smallest amount of residual oil (Hayes, Getter et al. 2003). An interesting piece of information we found was that in our experiment, the oil consumed almost identical amounts of oxygen in water as well as in the sediment. This could suggest that the microbial community associated with the weathered oil initially was dominant in the degradation process.

Like I said, I have not finished analyzing the data yet but am looking forward to continuing my work with Dr. Huettel and his grad students. I have had a very positive experience working hands on in a lab setting.

Post Author:
Corine Samaras