A SAMPLER FOR THE COLLECTION OF DISPERSED OIL DROPLETS

1989 ◽  
Vol 1989 (1) ◽  
pp. 567-568 ◽  
Author(s):  
Gerard A. L. Delvigne
Keyword(s):  
Oil Droplets ◽  
Dispersed Oil

OIL SPILL CLEANUP WITH DISPERSANTS: A BOOMED OIL SPILL EXPERIMENT

1981 ◽  
Vol 1981 (1) ◽  
pp. 263-268
Author(s):  
Joseph Buckley ◽  
David Green ◽  
Blair Humphrey
Keyword(s):  
Water Column ◽  
Oil Spill ◽  
Oil Spills ◽  
Sea Water ◽  
Visual Observation ◽  
Oil Droplets ◽  
Oil Boom ◽  
Dispersed Oil ◽  
Vertical Density ◽  
Oil Spill Cleanup

ABSTRACT Three experimental oil spills of 200, 400, and 200 litres (l) were conducted in October, 1978, in a semiprotected coastal area on Canada's west coast. The surface slicks were restrained with a Bennett inshore oil boom. The spilled oil was chemically dispersed using Corexit 9527, applied as a 10-percent solution in sea water and sprayed from a boat. The dispersed oil was monitored fluorometrically for some hours. Surface and dispersed oil were sampled for chemical analysis. The highest recorded concentration of dispersed oil was 1 part per million (ppm). After a short time (30 minutes), concentrations around 0.05 ppm were normal, decreasing to background within 5 hours. The concentrations were low compared to those expected for complete dispersion which, as visual observation confirmed, was not achieved. The dispersed oil did not mix deeper into the water column with the passage of time, in contrast to predicted behaviour and in spite of the lack of a significant vertical density gradient in the sea water. This was attributed to the buoyancy of the dispersed oil droplets and the limited vertical turbulence in the coastal locale of the experiment. The integrated quantity of oil in the water column decreased more rapidly than either the mean oil concentration of the cloud or the maximum concentration indicating that some of the dispersed oil was rising back to the surface. The surfacing of dispersed oil was confirmed visually during the experiment. The mixing action of the spray boat and breaker boards apparently created large oil droplets that did not form a stable dispersion. Horizontal diffusion of the dispersed oil was initially more rapid than expected, but the rate of spreading did not increase with time as predicted. The results imply that the scale of diffusion was larger than the scale of turbulence which again can be attributed to the locale of the experiment.

EFFECT OF MIXING ENERGY, MIXING TIME AND SETTLING TIME ON DISPERSION EFFECTIVENESS IN TWO BENCH-SCALE TESTING SYSTEMS

2008 ◽  
Vol 2008 (1) ◽  
pp. 651-656 ◽  
Author(s):  
Biplab Mukherjee
Keyword(s):  
Energy Dissipation ◽  
Size Distribution ◽  
Mixing Time ◽  
Tween 80 ◽  
Settling Time ◽  
Oil Droplets ◽  
Mixing Energy ◽  
Oil Dispersant ◽  
Dissipation Rates ◽  
Dispersed Oil

ABSTRACT Dispersion experiments were conducted in baffled-flask and paddle-jar mixing systems at five energy dissipation rates ranging from 4.8 × 10−4 to 1.6 × 10−1 J/kg-s. The objective of these experiments was to investigate the effects of mixing energy, mixing time, and settling time on dispersion effectiveness and size distribution of the chemically dispersed oil droplets. Two separate combinations of evaporatively weathered Mars crude oil premixed with dispersants differing in hydrophile-lipophile balance (HLB) (12 and 10) but having the same chemical composition (Tween 80 and Span 80 in dodecane) were used. Dispersion effectiveness increased with energy dissipation rate to a maximum and then leveled for all cases studied. In the baffled flask, dispersion effectiveness reached a maximum of 82 ± 5% irrespective of oil-dispersant combination. In the paddle jar, the maximum value of dispersion effectiveness was oil-dispersant specific, being at 87 ± 9% and 30 ± 11% for dispersant HLB 12 and 10, respectively. Mixing time did not seem to have a significant effect on dispersion effectiveness in comparison to the effects of energy dissipation rates and oil-dispersant combinations. The normalized volume distributions of the dispersed oil droplets were tri-modal in both systems, suggesting that multiple mechanisms of droplet formation occurred. The largest droplet mode disappeared from the size distribution in dispersions produced in the baffled flask when the mixing energy was >1.6 × 10−2 J/kg-s. A similar behavior was also observed in the paddle jar for the oil-dispersant combination of HLB 12, but not for HLB 10. Inclusion of a settling period of 20 minutes before collecting sample decreased the dispersion effectiveness in paddle jar but no significant changes were observed in the baffled flask system. The differences observed were due to the differences in the size distributions of the dispersed oil droplets generated in these two systems.

scholarly journals Effects of Chemical Dispersant on the Surface Properties of Kaolin and Aggregation with Spilled Oil

2021 ◽  
Author(s):  
Wenxin Li ◽  
Yue Yu ◽  
Deqi Xiong ◽  
Zhixin Qi ◽  
Sinan Fu ◽  
...  
Keyword(s):  
Crude Oil ◽  
Surface Properties ◽  
Oil Spills ◽  
Size Ratio ◽  
Small Scale ◽  
Oil Droplets ◽  
Mineral Aggregate ◽  
Chemical Dispersant ◽  
Dispersed Oil ◽  
Spilled Oil

Abstract After oil spills occur, dispersed oil droplets can collide with suspended particles in the water column to form the oil-mineral aggregate (OMA) and settle to the seafloor. However, only a few studies have concerned the effect of chemical dispersant on this process. In this paper, the mechanism by which dispersant affects the surface properties of kaolin as well as the viscosity and oil-seawater interfacial tension (IFTow) of Roncador crude oil were separately investigated by small scale tests. The results indicated that the presence of dispersant impairs the zeta potential and enhances the hydrophobicity of kaolin. The viscosity of Roncador crude oil rose slightly as the dosage of dispersant increased while IFTow decreased significantly. Furthermore, the oil dispersion and OMA formation at different dispersant-to-oil ratio (DOR) were evaluated in a wave tank. When DOR was less than 1:40, the oil enhancement of dispersant was not significant. In comparison, it began to contribute when DOR was over 1:40 and the effect became more pronounced with the increasing DOR. The adhesion between oil droplets and kaolin was inhibited with the increasing DOR. The size ratio between oil droplets and particles is the significant factor for OMA formation. The closer the oil-mineral size ratio is to 1, the more difficultly the OMA forms.

scholarly journals Rise Velocity of Dispersed Oil Droplets by Underwater Application of Dispersants

2016 ◽  
Vol 51 (3) ◽  
pp. 367-374
Author(s):  
Osamu Miyata ◽  
Shoichi Hara ◽  
Hiroshi Kagemoto
Keyword(s):  
Rise Velocity ◽  
Oil Droplets ◽  
Dispersed Oil ◽  
Underwater Application

scholarly journals A Novel Experiment in the Baltic Sea Shows that Dispersed Oil Droplets Can Be Distinguished by Remote Sensing

Oceanography ◽  
2021 ◽  
pp. 60-61
Author(s):  
Kamila Haule ◽  
◽  
Włodzimierz Freda ◽  
Henryk Toczek ◽  
Karolina Borzycka ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Baltic Sea ◽  
The Baltic Sea ◽  
Oil Droplets ◽  
Dispersed Oil ◽  
The Baltic

scholarly journals Influence of Dispersed Oil on the Remote Sensing Reflectance—Field Experiment in the Baltic Sea

Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5733
Author(s):  
Kamila Haule ◽  
Henryk Toczek ◽  
Karolina Borzycka ◽  
Mirosław Darecki
Keyword(s):  
Remote Sensing ◽  
Field Experiment ◽  
Baltic Sea ◽  
Oil Spills ◽  
Light Flux ◽  
Natural Seawater ◽  
Oil Droplets ◽  
Maximal Increase ◽  
Remote Sensing Reflectance ◽  
Dispersed Oil

Remote sensing techniques currently used to detect oil spills have not yet demonstrated their applicability to dispersed forms of oil. However, oil droplets dispersed in seawater are known to modify the local optical properties and, consequently, the upwelling light flux. Theoretically possible, passive remote detection of oil droplets was never tested in the offshore conditions. This study presents a field experiment which demonstrates the capability of commercially available sensors to detect significant changes in the remote sensing reflectance Rrs of seawater polluted by six types of dispersed oils (two crude oils, cylinder lubricant, biodiesel, and two marine gear lubricants). The experiment was based on the comparison of the upwelling radiance Lu measured in a transparent tank floating in full immersion in seawater in the Southern Baltic Sea. The tank was first filled with natural seawater and then polluted by dispersed oils in five consecutive concentrations of 1–15 ppm. After addition of dispersed oils, spectra of Rrs noticeably increased and the maximal increase varied from 40% to over three-fold at the highest oil droplet concentration. Moreover, the most affected Rrs band ratios and band differences were analyzed and are discussed in the context of future construction of algorithms for dispersed oil detection.

SOME RECENT OBSERVATIONS REGARDING THE UNIQUE CHARACTERISTICS AND EFFECTIVENESS OF SELF-MIX CHEMICAL DISPERSANTS

1977 ◽  
Vol 1977 (1) ◽  
pp. 387-390
Author(s):  
Gerard P. Canevari
Keyword(s):  
Droplet Size ◽  
Oil Spills ◽  
Synergistic Effects ◽  
Toxic Substances ◽  
Mechanical Mixing ◽  
Oil Droplets ◽  
Dispersed Oil ◽  
Study Results ◽  
Micron Diameter ◽  
Spilled Oil

ABSTRACT There has been an increasing awareness of the utility of conventional chemical dispersants in general, and self-mix dispersants in particular as a viable means to minimize damage from oil spills. This paper will update the use of, and activity regarding the self-mix dispersant as noted in applications over the past two years. In addition, those aspects that are still little understood are discussed. Specifically, uniformly sized, dispersed oil droplets of approximately 1 micron diameter are formed by the diffusion action of self-mix chemical dispersants. The droplet size influences the dilution rate of the spilled oil in field applications, and data to support this are presented. The results of laboratory bioassays performed with these much smaller dispersed oil droplets, as opposed to larger droplets formed with mechanical mixing, can be misinterpreted since the increased rate of dilution afforded by smaller droplet size is not replicated. In addition to the vital dilution study results, this paper also presents evidence to clarify several popular misconceptions regarding chemical dispersants. For example, it is explained that the apparent synergistic effects between oil and dispersant do not indicate that chemical dispersants release toxic substances from the oil into the water. Data is also presented which shows that dispersants do not cause the oil to sink.

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