La fuoriuscita di petrolio della Deepwater Horizon del 2010 è stata la più grande fuoriuscita di petrolio marino nella storia degli Stati Uniti. Il disastro è stato causato dall'esplosione della piattaforma petrolifera Deepwater Horizon, che non solo ha causato 11 vittime alla volta, ma ha anche rilasciato quasi 210 milioni di galloni di petrolio greggio nel Golfo del Messico.
Dodici anni dopo, centinaia di milioni di dollari sono stati spesi in risposta a questo evento catastrofico e gli scienziati stanno lavorando per capire dove finisce tutto questo petrolio, un concetto noto come destino ambientale.
I destini più comunemente discussi delle fuoriuscite di petrolio in mare sono la biodegradazione (i microrganismi consumano e scompongono il petrolio), l'evaporazione (l'olio liquido si trasforma in gas) e l'adsorbimento dopo che il petrolio si è arenato sulle coste.
A team from the Woods Hole Oceanographic Institution (WHOI) has found that after the Deepwater Horizon disaster, nearly 10 percent of the oil floating in the Gulf was dissolved by sunlight into seawater - a process known as "photolysis". ". The findings are published today in the paper "Sunlight-driven dissolution is the main fate of offshore oil" in the journal Science Advances.
"During the 2010 Deepwater Horizon spill, the amount of oil that was converted by sunlight into compounds dissolved in seawater was different from what we usually know about the fate of oil (such as Biodegradation and stranding on shorelines) are comparable."
"One of the most fascinating aspects of this discovery is that it may affect our understanding of where oil is going elsewhere, and whether the outcome is good or bad," said lead author Danielle Haas Freeman, a student in the joint MIT/WHOI project. Say.
"If a significant portion of this oil is converted by sunlight and dissolved into seawater, it could mean that less oil ends up elsewhere, such as in sensitive coastal ecosystems. On the other hand, we have to consider the impact of these compounds on marine life. impact to determine whether the net result is positive or negative."
To make this important discovery, Freeman and Ward used a custom light-emitting diode (LED) reactor to measure how the velocity of this oil's fate changed under different types of light, such as ultraviolet and visible light.
"The process by which oil has been found to photolysis has actually been around for more than 50 years," Ward said. "But what's new here is that we understand how this process changes with the wavelength of light, which we determined using an LED reactor. This is key information that allows us to estimate the importance of this process during a leak."
Nuovi metodi di misurazione che utilizzano i LED offrono anche l'opportunità di determinare quali condizioni sono più importanti nel controllo del processo. Il team ha creato ipotetici scenari di fuoriuscita con diversi spessori di marea nera, diversi periodi dell'anno, diverse località nel mondo e diversi tipi di luce. Ciò che hanno notato è che alcune di queste condizioni mutevoli erano più importanti di altre.
Oil at the ocean's surface may have a new fate, a concept that has major implications for developing future oil spill research and spill response strategies. It is not known what the fate and potential toxicity of these sunlight-generated compounds are, making it challenging to assess the impact of this oil's fate. The researchers encourage the field to lean toward these gaps in knowledge.
"While our findings suggest that a significant portion of surface oil can dissolve into the ocean upon exposure to sunlight, the logical next step is to assess its persistence and potential harm to aquatic animals," Ward said.
