Featured Image Caption: Marine oil spills wreak havoc on all they touch, affecting mammals, birds, turtles, fish, and, of course, humans, as they put our food supply at risk of contamination. (Image Source: “Oil spill slick at NSRCC, Tanah Merah” by Ria Tan, licensed under CC BY-NC-ND 2.0).
Reference: Bi, H., An, C., Mulligan, C.N., Chen, Z., Lee, K., Wen, J., Qu, Z., & Chen, X (2022). Application of Phase-Selective Organogelators (PSOGs) for Marine Oil Spill Remediation. Journal of Marine Science and Engineering, 10, 1111. https://doi.org/10.3390/jmse10081111
Oil spills are some of the most devastating, human-caused disasters that can affect marine ecosystems. In general terms, crude oil is the liquid remains of ancient plants and animals, which we use as fossil fuels to create electricity and power a great variety of economic practices. In other words, we rely heavily on oil at this time. However, oil can’t be found everywhere in the world and is often times shipped around the world, leaving us with the risk of oil spills.
Have you ever seen a tiny bit of cooking oil on water? All kinds of oils, including crude oil, float on the surface of water, making marine oil spills really hard to remediate, since it spreads over long distances and affects all kinds of marine animals that swim, fly, eat, and live close to the surface.
What Is Remediation?
Remediation is the removal of contaminants from any ecosystem. When contaminants have the potential to cause environmental damage or pose a risk to human health, remediation techniques are used to recover the contaminated soil, sediment, groundwater, or—in this case—marine surface water.
Current practices for marine oil spill remediation include:
- The use of physical barriers (called booms) in order to stop the spread of oil spills.
- The use of specialized boats (called skimmers) that are able to slowly remove the surface layer of oil on the ocean tides.
And other, more controversial, methods like:
- Burning the oil in place, warming the ocean beneath it and potentially harming marine biodiversity.
- The application of chemical dispersants, which allows oil to sink into the water column.
But what if there was an easier and quicker way to remediate crude oil spills?
Scientists have been working with a class of chemical compounds (organic chemicals – meaning that the compound has non-carbon atoms attached to carbon atoms) that can be used to turn crude oil into gel. These chemicals are called Phase-Selective Organogelators (PSOGs) – an impressive name for an even more impressive compound. When applied to the surface of marine oil spills, they gel-ify the oil, making it easier to clean up. In 2022, Huifang Bi and colleagues reviewed published papers about the types of PSOGs that have been applied on marine oil spills. They then described what chemical reactions or molecular properties allowed PSOGs to turn crude oil into gel in the presence of water and seawater.
How Do These Chemicals Work?
PSOGs interact with the crude oil through a number of different chemical mechanisms (like hydrogen bonding, van der Waals force, among others) until the crude oil is congealed. As can be seen in the figure below, it is faster and simpler to remediate oil spills when using congealers instead of other methods. Once the crude oil turns into gel, boats can recover the mass in a safer and less time-consuming way.
Next Mission: Stop Oil Spills Altogether
Sadly, crude oil is still an essential part of our world economy. Although alternate and renewable energy sources are being explored and applied, we still rely heavily on oil being shipped across the world. For now, oil spills remain a risk to our marine ecosystems. PSOGs are a new and exciting area of study that could help remediation efforts and minimize the damage oil spills do when said disasters occur. Thanks to these new developments in the field of marine biology, chemistry, and engineering, oil spills could be managed in a more safe and efficient way.