Wednesday, July 23, 2014

DOSS and Oil Spills

The molecular formula for dioctyl sodium sulfosuccinate, DOSS, is shown on the right. This is the anionic detergent molecule that was used to disperse the oil from the Deepwater Horizon spill in the Gulf of Mexico in 2010. When applied to an oil spill, DOSS decreases the size of oil droplete and prevents large oil slicks from forming.
BP applied about 1.84 million gallons of DOSS to the 210 million gallons of oil that is estimated to have gushed out of the oil well.
At the time it was believed that DOSS degraded rapidly in the environment so that it would not harm the marine environment.

Recent studies, however,  have shown that DOSS persists in the environment for much longer than was previously thought. Four years after the Gulf oil spill, DOSS remains present in deep-sea sediments and corals and in sand patties on Gulf beaches. mean for marine life or for the people who frequent the beaches? Scientists do not yet know what this might mean for marine life or for the people who frequent the beaches so some Gulf beaches have signs to warn people not to touch the sand patties.

Reference:
Helen K. White, Shelby L. Lyons, Sarah J. Harrison, David M. Findley, Yina Liu, Elizabeth B. Kujawinski. Long-Term Persistence of Dispersants following the Deepwater Horizon Oil Spill. Environmental Science & Technology Letters, 2014; 1 (7): 295 DOI: 10.1021/ez500168r

Further Reading:
http://www.ausetute.com.au/members/detergent.html (detergent tutorial for members)
http://www.ausetute.com.au/members/soaps.html (soaps tutorial for members)
http://www.ausetute.com.au/members/molecularformula.html (molecular formula tutorial for members)
http://www.ausetute.com.au/members/structural2D.html  (2-dimensional structural formula tutorial for members)
http://www.ausetute.com.au/members/condensedsf.html (Condensed structural formula tutorial for members)
http://www.ausetute.com.au/members/skeletal.html (Skeletal formula tutorial for members) 

Suggested Study Questions:
  1.  Explain why dioctyl sodium sulfosuccinate, DOSS, is an anionic detergent molecule.
  2. Give the name for the type of formula shown for dioctyl sodium sulfosuccinate, DOSS, in the article
  3. Identify the functional groups found on a dioctyl sodium sulfosuccinate, DOSS, molecule.
  4. Identify areas of the dioctyl sodium sulfosuccinate, DOSS, molecule that are:
    • hydrophilic
    • hydrophobic
  5. Explain how the dioctyl sodium sulfosuccinate, DOSS, molecule might dissolve in water.
  6. Explain how the dioctyl sodium sulfosuccinate, DOSS, molecule might dissolve in oil.
  7. Explain how dioctyl sodium sulfosuccinate, DOSS, molecules might help break an oil spoil up into smaller oil droplets.
  8. Write a complete 2-dimensional structural formula for dioctyl sodium sulfosuccinate, DOSS.
  9. Write a condensed structural formula for dioctyl sodium sulfosuccinate, DOSS.
  10. Write the molecular formula for dioctyl sodium sulfosuccinate, DOSS.

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