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2017-336:Diluted bitumen (dilbit), an oil sands product, may present new response challenges differing from conventional crude oil in terms of its potential environmental impacts. Simple naphthenic acids (NAs), a complex group of monocarboxylic acids, with a general formula CnH2n+zO2, may be present in the source bitumen or may be created by photolytic weathering. Knowing the composition and concentrations of NAs created during the photo-degradation process of dilbit will help understand the fate, behavior and toxicity of dilbit.In the present study, two diluted bitumen products, Cold Lake Blend (CLB) and Access Western Blend (AWB), were mixed with saltwater and irradiated with natural solar light (Ottawa, Canada, 45.4°N) over winter and summer seasons, to assess the impact of sunlight on the chemical fate of the dilbit. For comparison, a light, sweet crude oil was exposed under similar conditions. The samples were analyzed by high performance liquid chromatography-high resolution mass spectrometry to examine the molecular transformation of diluted bitumen by solar irradiation. The abundances of NAs in all three test oils increased significantly after 90 days of solar irradiation, strongly suggesting that polar NAs were formed by photolysis. Further, greater increases in NAs in the light crude were found than in the two dilbits. Similarly, the lighter oil had higher photolytic removal rates of petroleum hydrocarbons than the two dilbits.The concentrations of NAs in oils exposed during the summer were generally higher than those exposed in winter. During summer exposure, the abundance of total NAs increased up to the 30-day’s solar exposure, then fell again, indicating the transient nature of these compounds. However, net increases in polar NA compounds were observed for all the winter exposed samples. Greater increases were observed in the smaller NA compounds (average C-number decreased), also accompanied by an increase in saturation (average z-number decreased).These chemical changes strongly indicate the effect of sunlight on the potential behaviour, fate and effects of spilled oil, with creation of new resin group compounds and reduction of aromatics and saturates. These changes may affect the viscosity of the oil and its ability to uptake water. These chemical compositions also imply significant changes to the ecological effects of the oil following a spill when aged in sunlight.

As it is well established that application of chemical dispersant to oil slicks enhances the concentration of oil droplets and reduces their size, chemical dispersants are expected to enhance oil sedimentation if applied in coastal waters rich in suspended particulate matter (SPM) and if flocculation between chemically dispersed oil and SPM, which leads to formation of oil-SPM aggregates (OSAs), occurs readily. New laboratory experiments were conducted to establish a quantitative understanding of the process and to verify this hypothesis. This paper presents findings from experiments conducted using Standard Reference Material 1941b prepared by the National Institute of Standards and Technology, Arabian Medium, Alaska North Slope and South Louisiana crude oils, and Corexit 9500 and Corexit 9527 chemical dispersants. Results showed that OSAs do form with chemically dispersed oil. Oil sedimentation increases with sediment concentration and reach a maximum at a sediment-to-oil ratio of approximately 2:1 for most of the oils used. No obvious effect of chemical dispersant on oil sedimentation was measured for sediment concentration of 100 mg/L and higher. However, measured oil sedimentation was 3 to 5 times higher with chemical dispersant than with physically dispersed oil at low sediment concentration of 25 and 50 mg/L. UV epi-fluorescence microscopy showed that OSAs formed with chemically dispersed oil contain many oil droplets that are smaller than those trapped in OSAs formed with physically dispersed oil.

In this work, 14 fresh crude oils of different types and origins were analyzed by gas chromatography with mass-selective detection, and over 80 potentially diagnostic ratios were calculated based on the quantitation of isoprenoids, polycyclic aromatic hydrocarbons (PAHs), biomarkers, diamondoids, bicyclic sesquiterpanes and aromatic steranes, etc. Diagnostic power (DP) was calculated for the selection of the candidate source-sensitive diagnostic ratios and used to determine which ratios were most diagnostic among the crude oils studied. In order to investigate the effect of evaporative and biodegradative weathering on diagnostic ratios and thereby to differentiate weathering-resistant ratios from weathering-sensitive ratios, triplicate analyses were performed for two suites of reference oils, laboratory-evaporated Prudhoe Bay crude oils and laboratory-biodegraded Alberta Sweet Mixed Blend (ASMB) crude oils, respectively. Student'S t-test was used to statistically evaluate whether diagnostic ratios were significantly affected by weathering and to ensure that the observed change is not due to analytical variance. It was found that, diagnostic ratios generally remained consistent for oils with slight to medium evaporative weathering, only the ratios of those compounds with lower boiling points such as adamantanes changed greatly. For biodegraded oils, most of diagnostic ratios remained constant for lightly to moderately biodegraded oils; while most of diagnostic ratios with exception of certain triaromatic steranes and high-molecular-weight terpane and sterane biomarkers demonstrated significant changes for heavily biodegraded oils.

Examination of GC-MS chromatograms of bicyclic biomarker sesquiterpanes and diamondoids using their characteristic fragment ions provides another highly diagnostic means for correlation and differentiation of unknown spilled oil samples that are difficult to identify by current fingerprinting techniques. In this work, GC-FID and GC-MS fingerprinting analysis in conjunction with statistical data analysis of target oil hydrocarbons including sesquiterpanes and diamondoids was performed for identification of an unknown oil spill incident occurred in a harbor of the Netherlands in 2004. Forensic investigation included the: (1) identification and characterization of numerous sesquiterpanes and diamondoids; (2) comparison of the distribution of sesquiterpanes and diamondoids; (3) development of a series of diagnostic indices for correlation and differentiation of spilled fuel samples; and (4) use of “Two-tailed” unpaired Student'S t-test to statistically evaluate the imperceptible differences between the selected diagnostic ratios of target compounds in the spill fuel and the suspected source fuel samples. At a 95% confidence interval, 33 of all 38 diagnostic indices (among them, 20 are diagnostic indices of sesquiterpanes and diamondoids) show positive matches between spill sample and suspected source fuel sample 1. In comparison, only 5 of 38 diagnostic indices indicate positive matches between spill sample and suspected source sample 3. These evidences demonstrate that the bunker ship has the responsibility for this oil spill incident.

A new diagnostic parameter of “Pyrogenic Index (PI),” defined as(other 3–6 ring EPA priority PAHs)/N(5 alkylated PAHs), has been proposed as a quantitative indicator for identification of pyrogenic PAHs and for differentiating pyrogenic from petrogenic PAHs. It has been well understood that petrogenic and pyrogenic PAHs are characterized by dominance of five alkylated PAH homologues and by dominance of unsubstituted high molecular weight PAHs, respectively. In comparison with traditional diagnostic ratios such as phenanthrene/anthracene (Ph/An), benz[a]anthracene/chrysene (BaA/Ch), and fluoranthene/pyrene (Fl/Py), the PI Index more truly reflects the difference in the PAH distribution between these two sets of PAHs. The PI Index has been successfully used as an effective criterion to unambiguously differentiate pyrogenic and petrogenic PAHs. In this paper a case study is presented to illustrate the utility of the PI index to distinguish the pyrogenic PAHs generated by burning from the petrogenic PAHs. On October of 2004, a fire accident happened in the HMCE Chicoutimi submarine at sea off the west coast of Ireland as the submarine was making its way to Halifax, Canada. In order to determine effects of the fire accident on the health of crew members, a number of fire samples were collected and sent to the ESTD for characterization. Sample characterization results clearly revealed that the distribution profiles of PAHs in the samples are combined signatures from both pyrogenic and petrogenic PAHs. The pyrogenic PAHs were generated from the fire accident, while the petrogenic PAHs came from contamination of petroleum products used by the submarine. The presence of petroleum hydrocarbons is further confirmed by the discovery of oil-characteristic n-alkanes and biomarker compounds in the fire samples.

At the request of the US EPA Oil Program Center, the National Exposure Research Laboratory's Ecosystems Research Division (ERD) in Athens is developing an oil spill model that focuses on fate and transport of oil components under various response scenarios. A database of prototype oils for use in models is necessary. This multiple component composition data, however, is not typically available because of complexity of oil composition and the impossibility of immediate characterization in the event of a spill. Thus the creation of a database containing both physical property and chemical composition data for a number of common oils at various weathering percentages is highly desirable. The data set must be based upon fractionation of the oils into groups of compounds with similar structures and properties and further must reflect the changes to the oil over the course of the spill. Since 1984, the Emergencies Science and Technology Division (ESTD) of Environment Canada (EC) has developed a database on various physical and chemical properties of crude oils and petroleum products. Through many years endeavour, the database now contains information of hundreds of oils from all over the world. In 2002, funded by the US EPA and EC, the ESTD and ERD completed the cooperative project “Development of a Composition Database for Selected Multicomponent Oils,” to characterize ten prototype crude oils and refined petroleum products. The present work, Oil Composition and Property Database for Oil Spill Modeling, is a logical extension of the 2002 project. Nine new crude oils in common use and with potential to be spilled in the US waters were selected for inclusion in the model database. Comprehensive physical property measurement and chemical composition characterization have been performed for these oils at four weathered stages of each oil. This project provides the most complete and comprehensive database for the selected oils to date. The new composition data has been integrated into the existing US EPA and EC oil properties database. The results are made available to the public on the world wide web.

This paper describes a case study of an oil spill into Canal Ste-Anne-de-Bellevue, Quebec in 2002. In response to this specific oil identification need, a lab spill simulation was designed to obtain simulated spill samples from the suspected source samples. The integrated multi-criterion approach using GC/MS and GC/FID was then applied for fingerprinting and identifying the spill oil samples. The distribution patterns of hydrocarbons in the spill and suspected source samples were recognized and compared. Analysis of oil-characteristic biomarkers and the extended suite of parent and alkylated polycyclic aromatic hydrocarbons (PAH) were performed. A variety of diagnostic ratios of “source-specific marker” compounds for interpreting chemical fingerprinting data were determined and analyzed. Finally, the major components in suspected source samples were identified. The detailed chemical characterization data highlight that: (1) the spilled oil 264 is diesel fuel, while the suspected source sample 265 is an emulsified Bunker C type fuel; (2) another suspected source sample 266 is a de greaser-type “pine oil” product; (3) the synthetic spill sample from 265 and 266 has a completely different GC profile and chemical composition from the spill sample 264. No component of sample 266 was found and recognized in sample 264.

Orimulsion is an oil-in-water emulsion of Venezuelan bitumen. Orimulsion was found to behave predictably in salt (33°/oo NaCl) and fresh water, driven by buoyancy to rise in salt water and sink in fresh water; but behaviour in brackish water (20°/oo NaCl) was difficult to predict. Temperature has also been indicated as having an influence on Orimulsion behaviour. The current study extended experimentation down to lower temperatures, and a variety of mixing energies. This study resulted in new information on the behaviour of Orimulsion spills in salt, fresh, and brackish water with salinity values of 20 and 33 degrees at temperatures of 5 and 15 degrees Celsius. Energy was varied by adjusting the applied rotational field and measurement with thermal probes. Depletion rates and characteristics were determined by adding Orimulsion to a 300-L tank of water, taking a time series of samples, and determining the concentration of bitumen and the particle size distribution. Changes in bitumen concentration and particle size distribution as a function of time were also measured. Using these data, simple equations were developed to describe and predict the concentration of bitumen in the water column as a function of time. Similarly nomograms showing the amount of oil on the bottom and on the water surface are presented.

Studies have shown that Orimulsion behaves somewhat predictably in saltwater (33 ppt NaCl) and freshwater, driven by buoyancy to rise in saltwater and sink in freshwater, but behaviour in brackish water (20 ppt NaCl) is difficult to predict. Temperature has also been indicated as having an influence on Orimulsion behaviour. The current study extended experimentation to lower temperatures and a large number of salinity values, ranging from fresh to saltwater. This study resulted in information on the behaviour of Orimulsion spills in salt, fresh, and brackish water with salinity values ranging from 0.1 to 33 °/oo at temperatures of 5 and 15 °C. Depletion rates and characteristics were determined by adding Orimulsion to a 300-L tank of water, taking a time series of samples, and determining the concentration of bitumen and the particle size distribution. Changes in bitumen concentration and particle size distribution as a function of time were also measured. Resurfaced bitumen was scraped from the top of the tank and weighed to determine the amount rising. Using these data, simple equations were developed to describe and predict the concentration of bitumen in the water column as a function of time. Similarly, nomograms showing the amount of oil on the bottom and on the water surface are presented.

Multicomponent composition and corresponding physical properties data of crude oils and petroleum products are needed as input to environmental fate simulations. Complete sets of such data, however, are not available in the literature due to the complexity and expense of making the measurements. Environment Canada has previously developed a database of various physical and chemical properties of crude oils and petroleum products. In this cooperative project, ten “typical” crude oils and refined products in common use or transport were identified for subsequent characterization. Measured oil physical properties include API gravity, density, sulphur content, water content, flash point, pour point, viscosity, surface and interfacial tension, adhesion, the equation for predicting evaporation, emulsion formation, and simulated boiling point distribution. The chemical composition of the oils are quantified for hydrocarbon groups, volatile organic compounds, n-alkane distribution, distribution of alkylated polyaromatic hydrocarbon (PAH) homologues and other EPA priority PAHs, and biomarker concentrations. This project will provide the most complete and comprehensive database for the selected oils to date. The new composition data will be integrated into the existing Environment Canada oil properties database. The results will be made available to the public both on the world wide web and as a database on disc.

A comprehensive laboratory study of the Turner Instrument flow-through models 10AU and 10 fluorometers was conducted to review their ability to measure real-time oil-in-water concentrations and to further understand the relationship of the fluorescence to the chemical composition of the oils. The oils and dispersant used in the program were Alberta Sweet Mixed Blend (ASMB) crude oil (0% and 26% weathered samples), Prudhoe Bay (PB) crude oil (0% and 27% weathered samples), Bunker C (BC) fuel oil (0% and 8.4% weathered samples), Diesel fuel (0% and 37% weathered samples) and Corexit 9500 respectively. The chemical composition of the oils was determined by gas chromatographic techniques and compared to the signal outputs of the fluorometers. It was found that the fluorometer data could not be directly linked to the concentration of any specific aromatic hydrocarbon such as naphthalene or to the sum of the polycyclic aromatic hydrocarbon (PAH) compounds. Evidence suggests that the fluorescence signal is generated by a combination of PAH compounds. The relative contribution of each PAH compound is not equal. Finally, the response of the fluorometers may also be influenced by the presence of volatile aromatic compounds such as BTEX and C3- benzenes in combination with the PAH compounds.

A comprehensive laboratory study of the Turner Instrument flow-through fluorometers was conducted to review their ability to measure real-time oil-in-water concentrations, to compare the results to alternative total petroleum hydrocarbon (TPH) procedures and to carry out supporting laboratory analysis in order to further understand the relationship of the fluorescent signal to the composition of the oils. The model 10 AU was equipped with the long wavelength optical kit for crude oils while the model 10 was equipped with the short wavelength optical kit for diesel fuels and light refined oil products. Eight oils and the dispersant COREXIT®9500 were used. The oils were Alberta Sweet Mixed Blend crude oil (0% and 27% weathered), Prudhoe Bay crude oil (0% and 27% weathered), Bunker C fuel oil (0% and 8% weathered), and diesel fuel (0% and 37% weathered). Efforts were made to establish a calibration procedure which was used to convert the real-time fluorometer data to oil concentration. Initial comparisons of the fluorometer results to standard infrared and gas chromatography laboratory procedures showed all methods capable of detecting and differentiating between small changes in oil concentration. The infrared and gas chromatography generated similar values while the fluorometer values were of the same order of magnitude but typically 20 to 80% higher.

Complete “total oil analyses” were performed on the 24-year-old spilled Metula oil samples collected during the 1998 field visit. Fingerprinting data clearly indicate, except those three samples collected from the East Marsh untreated plots (EE-GO, EE-CI and EE-C2) that were only moderately weathered, the spilled oil has undergone significant alteration in chemical composition after 24 years. There are no fundamental differences between heavily weathered and degraded West Marsh and treated East Marsh samples. However, the effect of the experimental tilling action has been to promote plant recolonization. This result indicates that the recolonization of the marshes almost certain would have been accelerated had tilling or mixing been conducted on these sites after the spill. Chemical analyses of the two asphalt pavement samples (WI-1 and WI-2) indicate extremely heavy degradation. For these two samples, complete spectrum of n-alkanes from C8 to C40 and greater than 98% of alkylated PAH homologues were lost, and even the highly biodegradation-resistant biomarker compounds were shown to be more or less altered. It is observed that biomarkers were generally degraded in the declining order of importance as follows: diasteranes > C27 steranes > tricyclic terpanes > pentacyclic terpanes > norhapanes ∼C29 αββ steranes.

Over 45 mesoscale burns were conducted to study various aspects of diesel and crude oil burning in situ,. Extensive sampling and monitoring of these burns were conducted at downwind stations, upwind stations, and in the smoke plume. Particulate samples were taken in air and analyzed for polycyclic aromatic hydrocarbons (PAHs). PAHs were found to be lower in the soot than in the starting oil, although higher concentrations of the larger molecular PAHs were found in the soot and residue, especially for diesel burns. Overall, the amount of PAHs in the soot and residue were about 2 to 8% of that in the starting oil. This implies a destruction of PAHS by 92 to 98%. Particulates in the air were measured by several means and were found to be greater than recommended exposure levels up to 500 meters downwind at ground level, depending on the size and type of fire. Diesel fires emit much more particulate matter and have longer exposure zones. Combustion gases including carbon dioxide and carbon monoxide are below exposure level maximums. Volatile organic compound (VOC) emissions are extensive from fires, but the levels were less than from an evaporating crude oil spill. Over 140 compounds were identified and quantified. Carbonyls, including aldehydes and ketones, were found to below human health concern levels. Emission data from over 45 experimental burns have been used to develop prediction equations for over 150 specific compounds or emission categories. These are used to calculate safe distances and levels of concern for a standard burn size of 500 square meters, an amount that would typically be contained in a boom. The safe distance for a crude oil burn of this size is about 500 m and for a diesel burn, much further.

In 1994 and 1997, several U.S. and Canadian government agencies jointly conducted a series of mesoscale burns in Mobile Bay, Alabama, to study various aspects of in situ diesel fuel burning. Samples were taken from the oil, residue and the smoke plume during each burn and analysed by capillary gas Chromatograph/mass spectrometry (GC/MS). Analysis results reveal that the PAH distribution patterns in the diesel, residue, and soot samples are significantly different from each other. A simple model based on mass balance of individual petroleum ?AHs pre- and post-burn is proposed to estimate the destruction efficiencies of the total petroleum PAHs. The average destruction efficiency of the total diesel PAHs from three 1994 Mobile burns was estimated to be greater than 99%. The high molecular weight PAHs with five or more rings were found to be largely generated by combustion. These studies demonstrated that under certain circumstances, in situ burning is an effective measure to minimise the impact of an oil spill on the environment and to reduce the damage of an oil spill to the ecological system.

The ability to unambiguously identify spilled oils and petroleum products in complex contaminated environmental samples and to link them to the known sources is extremely important in settling questions of environmental impacts and liability. This paper will briefly review advanced chemical fingerprinting and data interpreting techniques used to identify sources of spilled oils. The chemical fingerprinting techniques discussed include pattern recognition evaluation of target petroleum hydrocarbon distributions; determination of major oil components and hydrocarbon groups; determination of diagnostic ratios of source-specific marker compounds such as PAHs and biomarkers; target PAH isomer analysis; and carbon isotopic ratio analysis. Methods for distinguishing biogenic and pyrogenic hydrocarbons from petrogenic hydrocarbons are also addressed. Several examples are presented to illustrate approaches to identifying and allocating multiple sources of hydrocarbons in complex hydrocarbon mixtures using these advanced chemical fingerprinting techniques.

Major advances have been made on analyses of petroleum hydrocarbons in oils, petroleum products and complex oil-spill-related environmental samples. This paper briefly describes how the advanced chemical fingerprinting and data interpretation techniques are used to identify the source(s) of tarballs from the coast of Vancouver Island and Northern California. Characterization of the unknown oil was achieved by not only a variety of “standard” analyses including distribution analyses of aliphatic, aromatic and biomarker hydrocarbons, but also analyses of diagnostic ratios of “source-specific marker” compounds, in particular the alkylated series of polycyclic aromatic hydrocarbons within the same alkylation isomeric groups. Results of the analysis revealed that (1) California/Oregon and British Columbia/Washington tarball samples were chemically similar, but were identified to be from two different types of bunker fuel; (2) the source of the tarball samples was neither Alaska North Slope oil nor California Monterrey Miocene oil; and (3) the spilled oil samples have been highly weathered since release, and the California samples were more heavily weathered than the British Columbia samples.

A group of 25 agencies from Canada and the United States conducted a major offshore burn experiment near Newfoundland, Canada. Two lots of oil, about 50 cubic meters (50 tons) each, were released into a fireproof boom. Each burn lasted over an hour and was monitored for emissions and physical parameters. Over 200 sensors or samplers were employed to yield data on over 2000 parameters or substances. The operation was extensive; more than 20 vessels, 7 aircraft and 230 people were involved in the operation at sea. The quantitative analytical data show that the emissions from this in-situ oil fire were less than expected. All compounds and parameters measured more than about 150 meters from the fire were below occupational health exposure levels; very little was detected beyond 500 meters. Pollutants were found to be at lower values in the Newfoundland offshore burn than they were in previous pan tests. Polyaromatic hydrocarbons (PAHs) were found to be lower in the soot than in the starting oil and were consumed by the fire to a large degree. Particulates in the air were measured by several means and found to be of concern only up to 150 meters downwind at sea level. Combustion gases including carbon dioxide, sulphur dioxide, and carbon monoxide did not reach levels of concern. Volatile organic compounds (VOCs) were abundant, however their concentrations were less than emitted from the nonburning spill. Over 50 compounds were quantified, several at levels of concern up to 150 meters downwind. Water under the burns was analyzed; no compounds of concern could be found at the detection level of the methods employed. Toxicity tests performed on this water did not show any adverse effect. The burn residue was analyzed for the same compounds as the air samples. Overall, indications from these burn trials are that 150 meters or farther from the burn source emissions from in-situ burning are lower than health criteria levels.

Using an oil chemical analysis method developed in our laboratory, more than 280 compounds in the Alberta Sweet Mixed Blend (ASMB) oil have been positively identified. The distribution of selected target compounds offers unique and sensitive fingerprints for matching the source of spilled oil and tracing the weathering process of oil in the environment. The pattern recognition plots involving more than 100 oil-specific individual components and component groupings permit deduction of a best set of values for oil exposure to weathering. Using data from different samples including crude oil, weathered oil, and 22-year-old spilled oil as examples, the distinct advantages of the described method over the current methods are examined.

On August 3, 2005, a Canadian National Railway train derailed within the Whitewood Sands community of the Wabamun Lake area. The derailment resulted in the release of 712,500 liters of Bunker C oil and 88,000 liters of pole treating oil from the rail cars into the adjacent Wabamun Lake water. To estimate the hydrocarbon-degrading capabilities of microbes naturally present in oil-contaminated Lake Wabamun sediment, laboratory tests were conducted at the University of Alberta under two incubation conditions. The tests incubated spilled Bunker C oil recovered from the lake and the reference oil, Alberta Sweet Mix Blend (ASMB), at 22°C for 4 weeks or at 4°C for 8 weeks. Residual oil was recovered and quantitatively characterized at the Oil Research Laboratory of Emergencies Science and Technology Section, Environment Canada. Biodegradation results demonstrated that Lake Wabamun sediment microbes were capable of degrading a significant proportion of the ASMB reference oil at both incubation temperatur...