Dispersion of spilled oil in freshwater systems: Field trial of a chemical dispersant

1990 ◽  
Vol 6 (1) ◽  
pp. 37-54 ◽  
Author(s):  
H.M. Brown ◽  
J.S. Goudey ◽  
J.M. Foght ◽  
S.K. Cheng ◽  
M. Dale ◽  
...  
Keyword(s):  
Field Trial ◽  
Freshwater Systems ◽  
Chemical Dispersant ◽  
Spilled Oil

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.

FREQUENCY OF DISPERSANT USE WORLDWIDE

2008 ◽  
Vol 2008 (1) ◽  
pp. 645-649 ◽  
Author(s):  
Alexis Steen ◽  
Abigail Findlay
Keyword(s):  
Mechanical Response ◽  
Open Water ◽  
Geographic Region ◽  
Response Option ◽  
Actual Frequency ◽  
Chemical Dispersant ◽  
The World ◽  
Spilled Oil

ABSTRACT Chemical dispersant use has been regarded in some areas of the world as a non-traditional response option for open water marine spills. This view is based on the historical prevalence of mechanical response and the additional regulatory or permitting requirements placed on organizations which wish to use dispersants. While such requirements may be a deterrent, the response community underestimates the actual frequency of dispersant use. Based on response reports for maritime spills, the frequency of worldwide dispersant use is summarized over the last four decades. Information is also summarized by the geographic region where the dispersant was applied and using any reports on effectiveness. Effectiveness reports are uneven in quality and, in many cases, absent. This situation underscores the importance of knowing if an oil is dispersible beforehand and monitoring the performance of a dispersant on a spilled oil afterward.

The Influence of Chemical Dispersants on the Properties of Crude Oil

2012 ◽  
Vol 608-609 ◽  
pp. 1387-1390
Author(s):  
Juan Sun ◽  
Dong Feng Zhao ◽  
Jing Sun ◽  
Chao Cheng Zhao
Keyword(s):  
Crude Oil ◽  
Heavy Oil ◽  
Aquatic Environment ◽  
Oil Spills ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Chemical Dispersant ◽  
Physical And Chemical ◽  
Spilled Oil ◽  
And Chemical Properties

After oil spills in the coastal aquatic environment, the physical and chemical properties of the spilled oil may change under the influence of the chemical dispersant and form emulsions in the water. This paper presents the results of a laboratory study on the influence of chemical dispersant to the properties of crude oil. The experiments were conducted using two widely-used surfactant GM-2 and BH-X, two crude oil samples and artificial seawater. Density, viscosity and emulsification rate of crude oil with different amounts of dispersant added was measured. The results show that viscosity of the crude oil was highly influenced by the chemical dispersant. The maximum emulsification rate of the Saudi Arabian middle crude oil was 54.1% and 57.4% with the dispersant to oil ratio above 0.8, whereas the emulsification rate of the heavy oil was significantly lower than the middle oil with both of the two types of chemical dispersant.

Jet Lag In Military Operations: Field Trial Of L-Tryptophan In Reducing Sleep-Loss Effects

1986 ◽  
Author(s):  
Cheryl L. Spinweber ◽  
Schuyler C. Webb ◽  
Christian Gillin
Keyword(s):  
Field Trial ◽  
Sleep Loss ◽  
Jet Lag ◽  
Military Operations

On-line Tropical Epidemiology -A Case-Study from The Gambia

1987 ◽  
Vol 26 (02) ◽  
pp. 73-76 ◽  
Author(s):  
Kathryn Rowan ◽  
P. Byass ◽  
R. W. Snow
Keyword(s):  
Data Collection ◽  
Field Trial ◽  
Error Rates ◽  
Database Management System ◽  
Bed Nets ◽  
Completion Rates ◽  
On Line ◽  
Access To Data ◽  
Rapid Processing

SummaryThis paper reports on a computerised approach to the management of an epidemiological field trial, which aimed at determining the effects of insecticide-impregnated bed nets on the incidence of malaria in children. The development of a data system satisfying the requirements of the project and its implementation using a database management system are discussed. The advantages of this method of management in terms of rapid processing of and access to data from the study are described, together with the completion rates and error rates observed in data collection.

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