of in situ burning for oil spill response, there are some limitations to applying this
method, including (a) fear of probable other fires and (b) environmental hazards and
danger to human health because of burning by-products (Buist et al. 1999). Burning
can have some effects on the aquatic life and vegetation near the site. In situ burning
is efficacious as treatment if applied immediately after the oil spill occurs (Dave and
Ghaly 2011). Thick oil slicks have an important role in spreading oil and the
efficiency of in situ burning. The spilled oil quickly spreads and becomes thin in
loose, broken ice conditions. The best range for thick slicks is 2–5 mm (Buist et al.
2011).
Secondary pollution, time consuming, excessive energy, and increasing water
temperature are the disadvantages of this method. The thickness of spilled oil is an
important factor to choose this method for oil removal.
12.4.2 Chemical Agent
Chemical agents are synthetic materials that are able to change the surface tension or
change the structure of oil molecules. These agents are used either alone or to
improve other methods like skimmers. Herding, dispersant, and solidifier agents
are familiar types of chemical agents that are used in oil removal processes.
Herding
The herding agents are used widely to clear and contract spilled oil in open water due
to their high spreading coefficient and specific surface activity. These chemical
materials, also called oil herders, form a monolayer on the surface of water and
increase the tension of oil/water surface. Then the herders change the balance of
interfacial forces and thicken the oil layer (Fig. 12.5).
Silicone-based, hydrocarbon-based, and fluorosurfactant-based are familiar types
of herders. Laboratory experiments have proved that the silicone-based herders have
the best performance followed by hydrocarbon-based and fluorosurfactant-based
herders. In general, the herder can improve some oil removal processes like skimmers and in situ burning techniques.
In light ice conditions, the proper performance of booms is questionable, the
challenging behavior of booms is contemplative. The small-scale and mid-scale
experiments showed that the herded slicks ignited well in brush and slush ice
conditions, even at 17
C. In these ice conditions, the efficiency of burning was
slightly less compared with open water. These results encouraged researchers to
carry out meso-scale experiments with 630 L of Heidrun crude. The oil spreading
lasted 15 min and thick slicks were reduced to 0.4 mm. After applying the herding
agents, the agents contracted and thickened the oil slicks and caused high oil removal
by burning (90%).
402
M. Fatehi et al.
method, including (a) fear of probable other fires and (b) environmental hazards and
danger to human health because of burning by-products (Buist et al. 1999). Burning
can have some effects on the aquatic life and vegetation near the site. In situ burning
is efficacious as treatment if applied immediately after the oil spill occurs (Dave and
Ghaly 2011). Thick oil slicks have an important role in spreading oil and the
efficiency of in situ burning. The spilled oil quickly spreads and becomes thin in
loose, broken ice conditions. The best range for thick slicks is 2–5 mm (Buist et al.
2011).
Secondary pollution, time consuming, excessive energy, and increasing water
temperature are the disadvantages of this method. The thickness of spilled oil is an
important factor to choose this method for oil removal.
12.4.2 Chemical Agent
Chemical agents are synthetic materials that are able to change the surface tension or
change the structure of oil molecules. These agents are used either alone or to
improve other methods like skimmers. Herding, dispersant, and solidifier agents
are familiar types of chemical agents that are used in oil removal processes.
Herding
The herding agents are used widely to clear and contract spilled oil in open water due
to their high spreading coefficient and specific surface activity. These chemical
materials, also called oil herders, form a monolayer on the surface of water and
increase the tension of oil/water surface. Then the herders change the balance of
interfacial forces and thicken the oil layer (Fig. 12.5).
Silicone-based, hydrocarbon-based, and fluorosurfactant-based are familiar types
of herders. Laboratory experiments have proved that the silicone-based herders have
the best performance followed by hydrocarbon-based and fluorosurfactant-based
herders. In general, the herder can improve some oil removal processes like skimmers and in situ burning techniques.
In light ice conditions, the proper performance of booms is questionable, the
challenging behavior of booms is contemplative. The small-scale and mid-scale
experiments showed that the herded slicks ignited well in brush and slush ice
conditions, even at 17
C. In these ice conditions, the efficiency of burning was
slightly less compared with open water. These results encouraged researchers to
carry out meso-scale experiments with 630 L of Heidrun crude. The oil spreading
lasted 15 min and thick slicks were reduced to 0.4 mm. After applying the herding
agents, the agents contracted and thickened the oil slicks and caused high oil removal
by burning (90%).
402
M. Fatehi et al.