Oil Concentration In Water Research Articles

FIBER-OPTICAL MEASUREMENTS OF MECHANICALLY AND CHEMICALLY DISPERSED OIL IN WATER

ABSTRACT A new fiber optical transmittance meter has been designed to measure oil concentrations in water. No electronic components are placed in the underwater sensor housings which are made relatively small to avoid influence on the surroundings. Both the light emitting diode and the receiver are synchroned demodulated. This together with AC-linked amplifiers in both the sender and receiver electronics give appropriate noise reduction. A transmittance meter was calibrated in a 1,0000:1 laboratory tank. Results from this calibration with mechanically dispersed Ekofisk crude oil and Reginol SAE 30 water-in-oil emulsion are presented. It was found that the beam attenuation increased almost exponentially up to a certain oil concentration which was a function of the particle size distribution and length of the waterpath of the light beam. The time changes in the concentration of dispersed oil under breaking waves in a wave tank in the laboratory have been measured at different depths below the surface. It was found that the oil concentrations decreased almost exponentially below the surface down to a depth approximately equal to the height of the breaking wave. During a full scale field experiment with oil in the North Sea in May 1982 the oil leakage under two different oil booms was measured with a beam transmittance meter at 1.5 m depth about 5 m behind the oil booms. Two-minute mean values of the beam transmittance were recorded. The measurements showed large variations in the oil concentrations behind the oil booms. Transmittance meter measurements also were carried out during offshore full scale tests with different chemical dispersants. The instruments have been towed at different depths from small boats passing through the slicks, measuring oil concentrations continuously at different levels simultaneously under the slicks. At Frigg in June 1984, the concentration of dispersed oil at 1, 2, and 3 m depth varied from (approximately) 0 to 60 ppm under one slick.

Oil dispersant field evaluation Ixtoc 1 blowout, bay of Campeche, Mexico

A chemical dispersant concentrate was aerially applied, at a rate of approximately 2 gal/acre (19 1 ha −2 ) to a crude oil slick emanating from the Ixtoc 1 well blowout. Chemical analyses of dispersant collected on pans at the sea surface beneath the swath of aerially-applied dispersant, showed no appreciable change in chemical composition from that of dispersant samples taken from holding tanks in the spray plane. Comparisons between oil concentrations in water at varying depths under the stick, determined before and approximately one hour after cispersant application, showed elevated concentrations of hydrocarbons in the water column. Photographs and visual observations from the research vessel and the two aircraft involved in the test indicated that application of dispersant did not cause ‘herding’ (lateral displacement) of the crude oil slick.

QUANTIFICATION OF NAVY OILS IN DETERGENT LADEN WATERS

ABSTRACT Accurate measurement of the concentration of oil in effluent discharged from ships is necessary so that water pollution regulations are not violated. Detergents used to clean machinery and deck surfaces aboard Navy ships often end up in bilge water and pass through gravitational and coalescence type oil/water separators. These detergents interfere in the solvent extraction and infrared (IR) spectrometry measurement technique for quantifying oil in water. They will absorb the IR energy at the wavelength used in quantifying oil; therefore, a method which can remove such interference, yet accurately measure the concentration of oil in water, is needed. A technique of eluting the solvent extract through silica gel removed most of this interference. Aqueous samples containing Navy oils and a non-ionic detergent in concentrations up to 1000 milligrams per liter were used to evaluate this technique. The solvent extract of these aqueous samples was filtered through silica gel and the IR absorbance of the effluent at 2,930 reciprocal centimeters was measured. The results demonstrated that this technique can yield the true concentration of oil in detergent laden water as long as the ratio of the concentration of detergent to oil is less than 10 to one. This technique can also be applied to quantify oil in water that does not contain detergent.

Ratio of Petroleum to Water During Primary Migration in Western Canada Basin: GEOLOGIC NOTES

Studies on the mechanism of primary migration involve some estimate of how much oil is carried out of the source rocks with the expelled water. A few ppM hydrocarbon in water can be explained by a solution mechanism but an oil-phase migration mechanism would require a much higher concentration of oil in water. The calculation of the oil/water ratio of fluids expelled during compaction of the Western Canadian basin was made for latitudes 49 to 60/sup 0/N. A table shows the porosity loss for each rock type and the total volume of water expelled from the fine-grained sediments. This porosity decrease calculates as a water loss of about 480,000 cu km, equivalent to about 480 x 10/sup 12/ MT for this part of the Western basin. Calculations are also made for ultimate recoverable oil potential and the mass of oil that is released by a given mass of source rocks. Results indicate that the quantity of hydrocarbons released from the source beds stand at about 6 to 16 percent of that still in place. (MCW)