scholarly journals MODIFICATION OF THE DISPERSANT COREXIT®9500 FOR USE IN FRESHWATER

2001 ◽  
Vol 2001 (2) ◽  
pp. 1209-1211 ◽  
Author(s):  
Anita George-Ares ◽  
Richard R. Lessard ◽  
Gerard P. Canevari ◽  
Kenneth W. Becker ◽  
Robert J. Fiocco
Keyword(s):  
Crude Oil ◽  
River Water ◽  
Calcium Chloride ◽  
Oil Spills ◽  
Deionized Water ◽  
North Slope ◽  
Low Salinity ◽  
A Value ◽  
Oil Spill Dispersants ◽  
Dispersant Effectiveness

ABSTRACT Recent inland spills in Latin America have generated interest in dispersant use for freshwater oil spills. However, oil spill dispersants primarily are formulated for use in marine waters. Dispersants that are designed for saltwater use show reduced effectiveness when applied in freshwater. The effectiveness of COREXIT® 9500 in low salinity waters varies with the type of oil, the dispersant-to-oil ratio (DOR), and other factors. The effectiveness of COREXIT® 9500 can decrease markedly at salinities of 15 ppt or less. The authors observed an increase in effectiveness of COREXIT® 9500 in freshwater when the dispersant was blended with an inorganic, divalent salt, such as calcium chloride, prior to use (patent pending). COREXIT® 9500* refers here to the blend of the salt and dispersant. The Exxon Dispersant Effectiveness Test (EXDET) was used to evaluate dispersant performance in deionized water and in river water samples from Rio de la Plata, Argentina. COREXIT® 9500 showed 22% effectiveness on Alaska North Slope (ANS) crude oil in deionized water, a value indicative of poor effectiveness. Depending on the amount of calcium chloride added, COREXIT® 9500* showed up to 63% effectiveness on ANS crude oil in deionized water, which indicates good effectiveness. The effectiveness of COREXIT® 9500* and COREXIT® 9500 was compared for three additional crude oils both in deionized water and in river water. In all cases, the effectiveness of COREXIT® 9500 was lower compared with COREXIT® 9500*.

DEGRADATION OF CRUDE OIL ENHANCED BY COMMERCIAL MICROBIAL CULTURES

1997 ◽  
Vol 1997 (1) ◽  
pp. 995-996 ◽  
Author(s):  
Salvador Aldrett ◽  
James S. Bonner ◽  
Thomas J. McDonald ◽  
Marc A. Mills ◽  
Robin L. Autenrieth
Keyword(s):  
Environmental Impact ◽  
Crude Oil ◽  
Laboratory Study ◽  
Biological Markers ◽  
Cost Efficiency ◽  
Oil Spills ◽  
North Slope ◽  
Standard Methods ◽  
Microbial Cultures ◽  
Biological Methods

ABSTRACT Remediation and cleanup of oil spills has been attempted using different technologies. Biological methods such as bioremediation have been favored over others due to their cost efficiency and their low environmental impact. Bioremediation of Alaska North Slope crude oil was effectively attempted in a laboratory study using 13 commercial products. The products containing the microorganisms were provided by different vendors. The treatments were tested over a 28-day period, and the samples were extracted and analyzed using standard methods. After 28 days, four products showed an effective enhancement of the bioremediation process: the saturate fraction was degraded approximately 80%, and the aromatic fraction was degraded approximately 70%. Biological markers such as pristane, phytane, and C30 hopane were partially degraded.

scholarly journals Physico-Chemistry of Surface Water Impacted by Crude Oil Spills in Bodo/Bonny Rivers, Nigeria

2021 ◽  
pp. 1-18
Author(s):  
David N. Ogbonna ◽  
Sebastine A. Ngah ◽  
Patrick O. Youdeowei ◽  
Matthew E. Origbe
Keyword(s):  
Electrical Conductivity ◽  
Surface Water ◽  
Crude Oil ◽  
River Water ◽  
Oil Spills ◽  
Ph Value ◽  
Oxygen Demand ◽  
Pond Water ◽  
Fish Pond ◽  
Physico Chemical

The surface water resources of Bodo/Bonny communities in Rivers State suffers regular pollution of its ecosystem due to increase in crude oil exploration, refining and activities of other industrial establishments operating within the coastal areas of the Ogoniland of the Niger Delta region of Nigeria.  This have resulted in the wide scale contamination of most of its creeks, swamps and rivers with hydrocarbons and dispersant products resulting in the alteration of the ecological integrity of fragile aquatic systems, bioaccumulation of chemical contaminants by zoobenthos, sediment enrichment, and smothering or asphyxiation of the organisms in water by oil coating, thereby causing death. These conditions have resulted in serious threat to public health and the ecosystems. The study was aimed at determining the physico-chemical characteristics of Bodo/Bonny coastal waters impacted by crude oil spills and their effect on the marine ecosystems. Surface water was collected from 5 stations (BBW1, BBW2, BBW3, BBW4 and LFPW5) with LFPW5 serving as control. Physico-chemical parameters were investigated following standard methods. The results of the physicochemical characteristics of the various sampling points in the dry season showed that pH, TDS and Electrical conductivity values showed statistically significant differences at   P < 0.005. pH was slightly acidic in all sampling locations except for the Link fish pond, the values ranged from 6.20–6.40 which was below DPR Limit of 6.5-8.5 for potable water, TDS recorded 43175–57075 mg/L above DPR permissible Limit of 5000mg/L. Electrical Conductivity (EC) values ranged from 54050 -57050 µS/cm. The Dissolved Oxygen, Biological Oxygen Demand, Turbidity, Chloride recorded in this study varied significantly at P< 0.05. Results of the physicochemical parameters of surface water in the wet season fell within the standard limits except for the conductivity that was above the permissible limits. Comparatively the mean pH value of surface river water with Linked fish pond water which served as the control revealed that the Link fish pond water had the highest pH value of 7.9 than the surface river water samples with a pH of 6.4, TDS (60,200 mg/L), Electrical Conductivity (EC) (µS/cm3) followed a similar pattern with the mean EC value of 55,800 mg/L as against 750mg/L for the Link Fish pond water. Temperature recorded 310C as against 300C for the link fish pond while the Salinity (mg/L) of the surface river water was 31.63 mg/L. Dissolved Oxygen was  2.3 mg/L, Biochemical Oxygen Demand values for the surface river water was 0.49 mg/L while the Link fish pond water had 0.3mg/L. These values obtained in this study shows that the spilled oil in the water could impact on species abundance and biomass by depleting and depriving the fishes from available O2 for survival thus resulting in asphyxiation.

DISPERSANT EFFECTIVENESS ON OIL SPILLS – EMPIRICAL CORRELATIONS

2008 ◽  
Vol 2008 (1) ◽  
pp. 801-804
Author(s):  
Kavitha R. Nagarajan ◽  
Niranjan Deshpande ◽  
George A. Sorial ◽  
James W. Weaver
Keyword(s):  
Experimental Data ◽  
Crude Oil ◽  
Oil Spills ◽  
Refined Oil ◽  
Mixing Energy ◽  
Oil Slick ◽  
Different Temperatures ◽  
Dispersant Effectiveness ◽  
The Impact ◽  
Full Factorial

ABSTRACT When a dispersant is applied to an oil slick, its effectiveness in dispersing the spilled oil depends on various factors such as oil properties, wave mixing energy, temperature of both oil and water, and salinity of the water. Estuaries represent water with varying salinities. In this study three salinity values in the range of 10–34 ppt were investigated, representing potential salinities found in typical estuaries. Three oils were chosen to represent light refined oil, light crude oil and medium crude oil. Each oil was tested at three weathering levels to represent maximum, medium and zero weathering. Two dispersants were chosen for evaluation. A modified trypsinizing flask termed the ‘Baffled Flask’ was used for conducting the experimental runs. A full factorial experiment was conducted for each oil to investigate the effect of salinity (3 levels), temperature (6 levels), oil weathering (3 levels) and mixing energy (150, 200, and 250 rpm) on dispersant effectiveness. Each experiment was replicated four times in order to evaluate the accuracy of the test. Statistical analyses of the experimental data were performed separately for each of the three oils three times (with or without dispersant). Viscosity of the three oils at the different temperatures and weathering conditions were determined. An empirical correlation of the viscosity for each of the three oils was then obtained. A linear regression model incorporating the viscosity correlations to represent temperature and weathering, the other remaining main factors (salinity and flask speed) and second order interactions among the factors was developed and was found to accurately represent the experimental data. The empirical approach to the interaction between the dispersant and oil slick developed could provide a useful or practical approach for including dispersants in a model to assess the impact of dispersant usage on oil spills.

scholarly journals Dispersant effectiveness on oil spills – impact of salinity

2006 ◽  
Vol 63 (8) ◽  
pp. 1418-1430 ◽  
Author(s):  
Subhashini Chandrasekar ◽  
George A. Sorial ◽  
James W. Weaver
Keyword(s):  
Experimental Data ◽  
Crude Oil ◽  
Oil Spills ◽  
Refined Oil ◽  
Light Crude Oil ◽  
Mixing Energy ◽  
Oil Dispersant ◽  
Dispersant Effectiveness ◽  
Almost All ◽  
The Impact

Abstract When a dispersant is applied to an oil slick, its effectiveness in dispersing the spilled oil depends on factors such as oil properties, wave-mixing energy, temperature, and salinity of the water. Estuaries represent water with varying salinity, so in this study, three salinity values in the range 10–34 psu were investigated, representing potential salinity concentrations found in typical estuaries. Three oils were chosen to represent light refined oil, light crude oil, and medium crude oil. Each was tested at three weathering levels to represent maximum, medium, and zero weathering. Two dispersants were chosen for evaluation. A modified trypsinizing flask termed a baffled flask was used to conduct the experimental runs. A full factorial experiment was conducted for each oil. The interactions between the effects of salinity and three environmental factors, temperature, oil weathering, and mixing energy, on dispersion effectiveness were investigated. Each experiment was replicated four times in order to evaluate the accuracy of the test. Statistical analyses of the experimental data were performed for each of the three oils independently for each dispersant treatment (two dispersants and oil controls). A linear regression model representing the main factors (salinity, temperature, oil weathering, flask speed) and second-order interactions among the factors was fitted to the experimental data. Salinity played an important role in determining the significance of temperature and mixing energy on dispersant effectiveness for almost all the oil–dispersant combinations. The impact of salinity at different weathering was only significant for light crude oil with dispersant A.

scholarly journals Changes of Heart Rate and Lipid Composition in Mytilus Edulis and Modiolus Modiolus Caused by Crude Oil Pollution and Low Salinity Effects

2021 ◽  
Vol 11 (2) ◽  
pp. 46-60
Author(s):  
Igor Bakhmet ◽  
Natalia Fokina ◽  
Tatiana Ruokolainen
Keyword(s):  
Heart Rate ◽  
Crude Oil ◽  
Mytilus Edulis ◽  
Lipid Composition ◽  
Oil Pollution ◽  
Cardiac Activity ◽  
Blue Mussels ◽  
Low Salinity ◽  
Crude Oil Pollution ◽  
Modiolus Modiolus

Blue mussels, Mytilus edulis, inhabiting tidal zones, are naturally exposed to fluctuating environmental conditions (e.g., fluctuations in temperature and salinities), while horse mussels, Modiolus modiolus, live under relatively invariable shelf water conditions. The present investigation tested the hypothesis: blue mussels, in comparison to horse mussels, have an increased ability to tolerate the stress of pollution combined with low salinity. To assess the response of blue mussels and horse mussels to oil pollution at seawater salinities of 25 psu (normal) and 15 psu (low), we used a combination of heart rate and lipid composition as physiological and biochemical indicators, respectively. A sharp decrease in heart rate as well as important fluctuations in cardiac activity was observed under all oil concentrations. Modifications in the concentrations of the main membrane lipid classes (phosphatidylcholine, phosphatidylethanolamine, and cholesterol) and storage lipids (primarily triacylglycerols) in response to different crude oil concentrations were time- and dose-dependent. Both chosen indicators showed a high sensitivity to crude oil contamination. Furthermore, both bivalve species showed similar responses to oil pollution, suggesting a universal mechanism for biochemical adaptation to crude oil pollution.

scholarly journals Bulk and Surface Aqueous Speciation of Calcite: Implications for Low-Salinity Waterflooding of Carbonate Reservoirs

SPE Journal ◽  
2017 ◽  
Vol 23 (01) ◽  
pp. 84-101 ◽  
Author(s):  
Maxim P. Yutkin ◽  
Himanshu Mishra ◽  
Tadeusz W. Patzek ◽  
John Lee ◽  
Clayton J. Radke
Keyword(s):  
Ionic Strength ◽  
Ion Exchange ◽  
Crude Oil ◽  
Surface Charge ◽  
Double Layer ◽  
Carbonate Reservoir ◽  
Carbonate Reservoirs ◽  
Diffuse Double Layer ◽  
Low Salinity ◽  
Low Salinity Waterflooding

Summary Low-salinity waterflooding (LSW) is ineffective when reservoir rock is strongly water-wet or when crude oil is not asphaltenic. Success of LSW relies heavily on the ability of injected brine to alter surface chemistry of reservoir crude-oil brine/rock (COBR) interfaces. Implementation of LSW in carbonate reservoirs is especially challenging because of high reservoir-brine salinity and, more importantly, because of high reactivity of the rock minerals. Both features complicate understanding of the COBR surface chemistries pertinent to successful LSW. Here, we tackle the complex physicochemical processes in chemically active carbonates flooded with diluted brine that is saturated with atmospheric carbon dioxide (CO2) and possibly supplemented with additional ionic species, such as sulfates or phosphates. When waterflooding carbonate reservoirs, rock equilibrates with the injected brine over short distances. Injected-brine ion speciation is shifted substantially in the presence of reactive carbonate rock. Our new calculations demonstrate that rock-equilibrated aqueous pH is slightly alkaline quite independent of injected-brine pH. We establish, for the first time, that CO2 content of a carbonate reservoir, originating from CO2-rich crude oil and gas, plays a dominant role in setting aqueous pH and rock-surface speciation. A simple ion-complexing model predicts the calcite-surface charge as a function of composition of reservoir brine. The surface charge of calcite may be positive or negative, depending on speciation of reservoir brine in contact with the calcite. There is no single point of zero charge; all dissolved aqueous species are charge determining. Rock-equilibrated aqueous composition controls the calcite-surface ion-exchange behavior, not the injected-brine composition. At high ionic strength, the electrical double layer collapses and is no longer diffuse. All surface charges are located directly in the inner and outer Helmholtz planes. Our evaluation of calcite bulk and surface equilibria draws several important inferences about the proposed LSW oil-recovery mechanisms. Diffuse double-layer expansion (DLE) is impossible for brine ionic strength greater than 0.1 molar. Because of rapid rock/brine equilibration, the dissolution mechanism for releasing adhered oil is eliminated. Also, fines mobilization and concomitant oil release cannot occur because there are few loose fines and clays in a majority of carbonates. LSW cannot be a low-interfacial-tension alkaline flood because carbonate dissolution exhausts all injected base near the wellbore and lowers pH to that set by the rock and by formation CO2. In spite of diffuse double-layer collapse in carbonate reservoirs, surface ion-exchange oil release remains feasible, but unproved.

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