Chemical dispersant effectiveness testing: influence of droplet coalescence

Sterling, Michael C.; Bonner, James S.; Ernest, Andrew; Page, Cheryl; Autenrieth, Robin L.

doi:10.1016/j.marpolbul.2003.12.003

Cited by 37 publications

(23 citation statements)

References 21 publications

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“…In a closed system with little dilution potential, however, coalescence could be promoted by providing mixing energy over a prolonged period of time (NRC, 2005). Sterling et al (2004) has clearly demonstrated that increased mixing energy in an enclosed vessel promoted coalescence and resurfacing of dispersed oil droplets over time at a nominal OWR of 1:6,000, resulting in an incrementally reduced dispersed oil fraction in the aqueous phase.…”

Section: Discussionmentioning

confidence: 99%

Evaluating Chemical Dispersant Efficacy in an Experimental Wave Tank: 2—Significant Factors Determining In Situ Oil Droplet Size Distribution

Lee

King

et al. 2009

Environmental Engineering Science

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Chemical dispersion is one of the most cost-effective options to remediate oil spill at open sea. Identifying significant factors that determine in situ droplet size distributions facilitates mechanistic understanding of dispersant effectiveness. In this work, in situ dispersed oil droplet size distributions were characterized during testing of chemical dispersant effectiveness of two dispersants (Corexit 9500 and SPC 1000) on two oils [Medium South American (MESA) and Alaska North Slope (ANS)] under three wave conditions (regular nonbreaking, spilling breaking, and plunging breaking waves) in an experimental wave tank. Results showed that physical dispersion generated monomodal lognormal oil droplet size distributions of larger median diameters, whereas chemical dispersion produced bi-or trimodal lognormal oil droplet size distributions of smaller median diameters over a wider range. Factorial analysis of variance (ANOVA) followed by Tukey's paired comparison statistical data analysis indicated that the volume mean diameters of dispersed oil droplets were reduced by 36 mm (from 122 to 86 mm) by plunging breaking conditions. Volume mean diameters were decreased by 92 mm (from 153 to 61 mm) and 37 mm (from 153 to 116 mm), respectively, by Corexit 9500 and SPC 1000. These results are useful in optimizing operational guidelines for dispersant use, and providing input for modeling transport, fate, and biological effects of dispersed oil.

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Section: Discussionmentioning

confidence: 99%

Evaluating Chemical Dispersant Efficacy in an Experimental Wave Tank: 2—Significant Factors Determining In Situ Oil Droplet Size Distribution

Lee

King

et al. 2009

Environmental Engineering Science

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“…This is consistent with the report of Oyewo (1986), which stated that some dispersants used in Nigeria were relatively highly toxic to some aquatic organisms. Ross (1997) also stated that the dispersant used for treating the Torrey canyon oil spill that occurred in Britain in 1967 turned out to be highly toxic and resulted in the mortality of crustaceans, molluscs, and other animals in the dispersant treated areas. Similarly, Nelson-Smith (1967) also reported that one of the most serious problems associated with the early use of dispersants was the toxicity of the dispersants themselves, particularly those whose solvent fractions consisted of a mixture of hydrocarbons.…”

Section: Discussionmentioning

confidence: 99%

Estimation of “environmentally sensitive” dispersal ratios for chemical dispersants used in crude oil spill control

Otitoloju

Popoola

2009

Environmentalist

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The toxicities of two dispersants (Biosolve and OSD 9460), Forcados light crude oil and their mixtures based on ratios 6:1, 9:1, and 12:1 (v/v) were evaluated against the juvenile stage of African catfish, Clarias gariepinus, in laboratory bioassays. On the basis of the derived toxicity indices, Biosolve (96-h LC 50 = 0.211 ll/l) was found to be about 27,284 times more toxic than crude oil (96-h LC 50 = 5.757 ml/l) and 6,450 times more toxic than OSD 9460 (96-h LC 50 = 1.361 ml/l). OSD 9460 was also found to be four times more toxic than crude oil when acting alone against C. gariepinus. Toxicity evaluations of the mixtures of crude oil/dispersants mixtures varied, depending largely upon the proportion of addition of the mixture components. The interactions between mixture of crude oil and Biosolve at the test ratios of 6:1, 9:1, and 12:1 were found to conform with the model of synergism (SR = 7,655, 14,876, and 8,792, respectively), and the mixtures were therefore more toxic than the crude oil acting singly. Similarly, the interactions between mixture of crude oil and OSD 9460 at the test ratios of 6:1 and 9:1 also conformed to the model of synergism (SR = 2.2 and 1.84, respectively). Interactions between the dispersant OSD 9460 and the crude oil at test ratio 12:1, however, conformed to the model of antagonism (SR = 0.84), indicating that the mixture was less toxic than crude oil acting alone. The results of the emulsification potential of OSD 9460 and Biosolve [measured in terms of optical transmittance (%)] prepared at the dispersal ratios 6:1, 9:1, and 12:1 revealed that the dispersal ratio of 6:1 achieved the highest emulsification of the crude oil with optical transmittance value of 4% and 6%, respectively. Estimation of an ''environmentally sensitive'' dispersal ratio for OSD 9460 and Biosolve revealed the optimum dispersal ratio for OSD 9460 range between ratios 7.5:1 and 9:1, while for Biosolve such an optimum dispersal ratio was indeterminate within the range of test dispersal ratios. The implications of these results in setting manufacturer's and regulatory dispersal ratios for chemical dispersants used for oil spill control were discussed.

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“…Dispersants efficiency is influenced by various factors [12,13]. Byford [14] showed that dispersants efficiency changes depending on salinity of water.…”

Section: Introductionmentioning

confidence: 99%

Petroleum-collecting and dispersing chemicals for cleaning sea surface from thin petroleum slicks

Asadov¹,

Zarbaliyeva²,

Rahimov³

et al. 2014

Bull. Chem. Soc. Eth.

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ABSTRACT. Monoethylolamide, diethylolamide and triethanolamine ester synthesized by us based on fish oil and their phosphate derivatives being surface-active and ecologically safe possess a high capacity of petroleum collecting and dispersing. When introducing phosphate group, a tendency to replacement of petroleum slick dispersing by its collection (accumulation into a spot) is observed. Efficiency of the chemicals change depends on the type and concentration of ions in the water. Such salts as NaCl, KI, KBr, and MgSO4 positively influence petroleum-collecting activity whereas K2CO3 and NaHCO3 cause petroleum dispersing.

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Chemical dispersant effectiveness testing: influence of droplet coalescence

Cited by 37 publications

References 21 publications

Evaluating Chemical Dispersant Efficacy in an Experimental Wave Tank: 2—Significant Factors Determining In Situ Oil Droplet Size Distribution

Evaluating Chemical Dispersant Efficacy in an Experimental Wave Tank: 2—Significant Factors Determining In Situ Oil Droplet Size Distribution

Estimation of “environmentally sensitive” dispersal ratios for chemical dispersants used in crude oil spill control

Petroleum-collecting and dispersing chemicals for cleaning sea surface from thin petroleum slicks

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