135
8 wt%, along the considered hypothetical water column. It is important to note here
that the partitioning behavior of organics at the time of the spill is very complex,
with factors such as plume dynamics and oil droplet size distribution influencing the
physics and kinetics of the processes. This study focuses primarily on the effects of
variations in the dissolved gas composition of oil and temperature on the dissolution
of organics into the water.
8.4.3 Use of Dispersants as a Spill Response Method
The ecological impact of addition of dispersants on human and environmental
health, following a spill has long been a point of contention (Kleindienst et al.
2016; Prince et al. 2016b; Rahsepar et al. 2016). Dispersants are often used as
a response method to promote natural dispersion of oil, by breaking up larger oil
volumes into smaller droplets and preventing the formation of oil slicks. While the
dispersants themselves contribute little to the toxicity, it is the oil that gets dispersed as a result of their application that largely governs the toxicity (Bobra et al.
1989; Ramachandran et al. 2004).
The dispersants, however, can remain in the environment for long periods of
time. Kujawinski et al. (2011) detected the DOSS (dioctyl sodium sulfosuccinate)
signature, a key component in the dispersant (Corexit) in the oil plume that was
formed at 1000–1200 m water depth near the Macondo wellhead, implying that
applied dispersant stayed in the water without appreciably degrading for 64 days
after the dispersant application ceased during the DWH oil spill. In certain environments, the addition of dispersants has been found to increase the absorption of polyaromatic hydrocarbons (PAHs) in aquatic species (Bobra et al. 1989; Ramachandran
et al. 2004). The dispersants also influence the microbial activity in the marine environment and have been known to both increase (Prince et al. 2016b) and suppress
the activity of specific oil-degrading microorganisms (Kleindienst et al. 2015).
The application of dispersants following an oil spill needs to be carefully evaluated in each environmental setting by weighing both merits and demerits and the
efficacy of alternative response methods.
8.5 Conclusions
The partitioning of organics between the oil and water phase is affected by changing
pressure and temperature trajectories during deepwater submarine oil spill scenarios. As gas-charged oil from a deep, high-pressure reservoir is injected into cold,
relatively lower-pressure water, dramatic changes in oil solution gas content, oil
polarity, and density will occur as gas exsolves from the oil and continues to exsolve
as the oil plume moves to shallower water. The traditional methods of assessing
8 Partitioning of Organics Between Oil and Water Phases with and Without…
8 wt%, along the considered hypothetical water column. It is important to note here
that the partitioning behavior of organics at the time of the spill is very complex,
with factors such as plume dynamics and oil droplet size distribution influencing the
physics and kinetics of the processes. This study focuses primarily on the effects of
variations in the dissolved gas composition of oil and temperature on the dissolution
of organics into the water.
8.4.3 Use of Dispersants as a Spill Response Method
The ecological impact of addition of dispersants on human and environmental
health, following a spill has long been a point of contention (Kleindienst et al.
2016; Prince et al. 2016b; Rahsepar et al. 2016). Dispersants are often used as
a response method to promote natural dispersion of oil, by breaking up larger oil
volumes into smaller droplets and preventing the formation of oil slicks. While the
dispersants themselves contribute little to the toxicity, it is the oil that gets dispersed as a result of their application that largely governs the toxicity (Bobra et al.
1989; Ramachandran et al. 2004).
The dispersants, however, can remain in the environment for long periods of
time. Kujawinski et al. (2011) detected the DOSS (dioctyl sodium sulfosuccinate)
signature, a key component in the dispersant (Corexit) in the oil plume that was
formed at 1000–1200 m water depth near the Macondo wellhead, implying that
applied dispersant stayed in the water without appreciably degrading for 64 days
after the dispersant application ceased during the DWH oil spill. In certain environments, the addition of dispersants has been found to increase the absorption of polyaromatic hydrocarbons (PAHs) in aquatic species (Bobra et al. 1989; Ramachandran
et al. 2004). The dispersants also influence the microbial activity in the marine environment and have been known to both increase (Prince et al. 2016b) and suppress
the activity of specific oil-degrading microorganisms (Kleindienst et al. 2015).
The application of dispersants following an oil spill needs to be carefully evaluated in each environmental setting by weighing both merits and demerits and the
efficacy of alternative response methods.
8.5 Conclusions
The partitioning of organics between the oil and water phase is affected by changing
pressure and temperature trajectories during deepwater submarine oil spill scenarios. As gas-charged oil from a deep, high-pressure reservoir is injected into cold,
relatively lower-pressure water, dramatic changes in oil solution gas content, oil
polarity, and density will occur as gas exsolves from the oil and continues to exsolve
as the oil plume moves to shallower water. The traditional methods of assessing
8 Partitioning of Organics Between Oil and Water Phases with and Without…