ChemCentre’s new Mackay Chamber simulates how oil behaves at sea and allows an insight into two factors; how oil weathers over time and the effectiveness of dispersants.
Weathering of oil at sea
When an oil spill occurs, the environment immediately begins altering the chemistry of the oil. As the oil is exposed to the churning sea, wind and sun, the volatile compounds (chemicals that easily evaporate) are lost. This results in an increase in density and viscosity (thickness) of the oil, eventually turning it into a thick, heavy blob of tar. The speed and extent at which this occurs varies depending on the specific type of oil, and environmental influences. The Mackay Chamber replicates air temperature, water temperature, wind speed and water salinity to profile these changes for up to 20 days.
Leif Cooper, ChemCentre’s resident oil spill expert and senior chemist explains how this information can be used:
“The information gathered by the Mackay Chamber along with data such as ocean currents, wind speeds and meteorology can be used to work out where the oil spill is going to go and predict what areas it’s going to impact.”
This ability to characterise the chemical progression and movement of an oil spill over time is vital to contingency planning.
Testing of dispersants on an oil slick
Determining the most effective cleanup method is also critical to contingency planning. Dispersants are one of the primary oil spill clean-up methods. They work in the same way that dishwashing liquid breaks up grease; one end of the dispersant molecule is soluble in water and the other end is soluble in oil. This in combination with the mechanical force of the waves breaks up thick oil slicks into small droplets that microorganisms can naturally break down.
The efficacy of dispersants must be tested and approved before being used in an emergency situation. Not all dispersants have the same effect on different oil types, so it is important to find the most effective matches.
Above: ChemCentre's new Mackay Chamber
An ineffective dispersant can be masked by the physical mixing of the ocean. Mackay Chamber trials can identify the difference between physical mixing and chemical mixing.
“If the physical droplets are too big they’re going to resurface and recreate the slick. Therefore, you want to distinguish between the oil that has been physically dispersed and is in small droplets and held under by the waves, from oil that has been chemically entrained into the water column and is going to stay there.”
The age and weathering of an oil slick can also alter the effectiveness of a dispersant. Typically, as an oil slick gets more viscous, dispersants become less effective. The Mackay Chamber is able to perform tests that identify the window of opportunity when a dispersant will be most effective on a particular oil.
To find out more about ChemCentre’s new Mackay Chamber contact us or email Leif Cooper directly at firstname.lastname@example.org