201
noted that penetration by mineral particles could result in the formation of larger
clusters (Zhao et al. 2016).
The concentration and size of solids involved in the interaction is an important
factor affecting the effectiveness of OMA formation. Payne et al. (2003) reported a
positive correlation between OMA formation and the concentration of suspended
sediments. Zhang et al. (2010) found smaller particle sizes of solids with larger
surface to volume ratios favored the formation of OMAs. The formation of OMAs
has been found to be more effective in marine environments than in freshwater environments (Fitzpatrick et al. 2015). While Gustitus and Clement (2017) found that
formation of OMAs was depressed when oil was weathered, others reported that
weathered oils tended to form OMAs more readily (Bragg and Yang 1995; Wood
et al. 1998).
The effectiveness of oil dispersion is positively correlated to the formation of
OMA/OPAs as smaller oil droplets require fewer suspended particles to form stable
aggregates (Gong et al. 2014; Gustitus and Clement 2017). Oil with higher viscosity
is more resistant to dispersing and form OMAs (Le Floch et al. 2002). Lee et al.
(1998) found the viscosity of oil needed to be less than 9500 mPa-s to form OMAs.
The addition of oil dispersants results in smaller oil droplets (Li et al. 2008; Zhao
et al. 2014, 2017) that favor the formation of OMA/OPAs. Hydrodynamic conditions that influence energy dissipation influence the dispersion of oil slicks (Li et al.
2008) and thus OMA formation (Omotoso et al. 2002; Wincele et al. 2004; Ma et al.
2008; Sun et al. 2010; Sun et al. 2014). Ma et al. (2008) demonstrated that once
OMAs are formed, they tend to be stable against continued turbulence. However,
Zhao et al. (2017) found that under turbulence, the OMAs can be further broken
down and recoalesce to form larger OMAs composed of multiple small droplets.
In terms of oil persistence, when suspended in the water column, the additional
reactive surface area afforded by the minerals or organic matter favors enhanced
rates of microbial oil biodegradation (Lee et al. 1997; Weise et al. 1999; Zhao et al.
2017). Thus, a number of experiments have been conducted to assess and demonstrate the feasibility of actively enhancing the formation of OMA as an alternative
response measure. Sediment relocation (surf washing) involves the transport of
oiled material from one section of a beach to another (i.e., the surf zone) where
higher mixing energy and subsurface mineral fines associated with the excavated
sediment accelerate the removal of oil from the sediments by the formation of OMA
which would disperse and enhance the degradation of the residual oil. This in situ
technique was demonstrated within the Arctic (Owens and Lee 2003; Lee et al.
2003a) and validated during actual oil spill response operations following the Sea
Empress oil spill in the UK (Lunel et al. 1996). The scope of this oil translocation
concept was further developed and tested as a potential strategy to remediate oil
spills in ice-infested waters (Lee et al. 2011). While temperature affects the formation of OMAs mostly by influencing the viscosity and adhesion properties of oil, the
formation of OMAs has been considered and demonstrated as a response to oil spills
in low-temperature conditions (−1 to −4 °C) in laboratorial batch scale tests (Lee
et al. 2012a; Wang et al. 2013), pilot-scale flume tank studies (Jézéquel et al. 2018),
and field trials in ice-infested waters under Arctic conditions (Lee et al. 2011).
12 Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA) Events…
noted that penetration by mineral particles could result in the formation of larger
clusters (Zhao et al. 2016).
The concentration and size of solids involved in the interaction is an important
factor affecting the effectiveness of OMA formation. Payne et al. (2003) reported a
positive correlation between OMA formation and the concentration of suspended
sediments. Zhang et al. (2010) found smaller particle sizes of solids with larger
surface to volume ratios favored the formation of OMAs. The formation of OMAs
has been found to be more effective in marine environments than in freshwater environments (Fitzpatrick et al. 2015). While Gustitus and Clement (2017) found that
formation of OMAs was depressed when oil was weathered, others reported that
weathered oils tended to form OMAs more readily (Bragg and Yang 1995; Wood
et al. 1998).
The effectiveness of oil dispersion is positively correlated to the formation of
OMA/OPAs as smaller oil droplets require fewer suspended particles to form stable
aggregates (Gong et al. 2014; Gustitus and Clement 2017). Oil with higher viscosity
is more resistant to dispersing and form OMAs (Le Floch et al. 2002). Lee et al.
(1998) found the viscosity of oil needed to be less than 9500 mPa-s to form OMAs.
The addition of oil dispersants results in smaller oil droplets (Li et al. 2008; Zhao
et al. 2014, 2017) that favor the formation of OMA/OPAs. Hydrodynamic conditions that influence energy dissipation influence the dispersion of oil slicks (Li et al.
2008) and thus OMA formation (Omotoso et al. 2002; Wincele et al. 2004; Ma et al.
2008; Sun et al. 2010; Sun et al. 2014). Ma et al. (2008) demonstrated that once
OMAs are formed, they tend to be stable against continued turbulence. However,
Zhao et al. (2017) found that under turbulence, the OMAs can be further broken
down and recoalesce to form larger OMAs composed of multiple small droplets.
In terms of oil persistence, when suspended in the water column, the additional
reactive surface area afforded by the minerals or organic matter favors enhanced
rates of microbial oil biodegradation (Lee et al. 1997; Weise et al. 1999; Zhao et al.
2017). Thus, a number of experiments have been conducted to assess and demonstrate the feasibility of actively enhancing the formation of OMA as an alternative
response measure. Sediment relocation (surf washing) involves the transport of
oiled material from one section of a beach to another (i.e., the surf zone) where
higher mixing energy and subsurface mineral fines associated with the excavated
sediment accelerate the removal of oil from the sediments by the formation of OMA
which would disperse and enhance the degradation of the residual oil. This in situ
technique was demonstrated within the Arctic (Owens and Lee 2003; Lee et al.
2003a) and validated during actual oil spill response operations following the Sea
Empress oil spill in the UK (Lunel et al. 1996). The scope of this oil translocation
concept was further developed and tested as a potential strategy to remediate oil
spills in ice-infested waters (Lee et al. 2011). While temperature affects the formation of OMAs mostly by influencing the viscosity and adhesion properties of oil, the
formation of OMAs has been considered and demonstrated as a response to oil spills
in low-temperature conditions (−1 to −4 °C) in laboratorial batch scale tests (Lee
et al. 2012a; Wang et al. 2013), pilot-scale flume tank studies (Jézéquel et al. 2018),
and field trials in ice-infested waters under Arctic conditions (Lee et al. 2011).
12 Marine Oil Snow Sedimentation and Flocculent Accumulation (MOSSFA) Events…