Polynuclear aromatic hydrocarbons petroleum

The fused 3+ ring aromatics in petroleum include both cata- and peri-condensed stmctures (see Table 4, Fig. 8). The cata-condensed species are those stmctures where only one face is shared between rings, the peri-condensed molecules are those that share more than one face. The fused ring aromatics form the class of compounds known as polynuclear aromatic hydrocarbons (PAH) which includes a number of recognized carcinogens in the 4+ ring family (33). Because of the potential health and environmental impact of PAH, these compounds have been studied extensively in petroleum. 

Table 4. Fused-Ring Polynuclear Aromatic Hydrocarbons Found in Petroleum ...

The petroleum-based oils contain hundreds to thousands of hydrocarbon compounds, including a substantial fraction of nitrogen- and sulfur-containing compounds. The hydrocarbons are mainly mixtures of snaight- and branched-chain hydrocarbons (alkanes), cycloalkanes, and aromatic hydrocarbons. Polynuclear aromatic hydrocarbons, alkyl polynuclear aromatic hydrocarbons, and metals are important components of motor oils and crankcase oils, with the used oils... 

Among the polynuclear aromatic hydrocarbons, the toxicity of petroleum is a function of its di- and triaromatic hydrocarbon content. Like the single aromatic... 

Supercritical fluid extraction (EPA 3540, for total recoverable petroleum hydrocarbons EPA 3561 for polynuclear aromatic hydrocarbons) is applicable to the extraction of semivolatile constituents. Supercritical fluid extraction involves heating and pressuring a mobile phase to supercritical conditions (where the solvent has the properties of a gas and a liquid). The supercritical fluid is passed through the soil sample, and the analytes are concentrated on a sorbent or trapped cryogenically. The analytes are eluted with a solvent and analyzed using conventional techniques. Carbon dioxide is the most popular mobile phase. 

After a plate has been exposed to the mobile-phase solvent for the required time, the compounds present can be viewed by several methods. Polynuclear aromatic hydrocarbons, other compounds with conjugated systems, and compounds containing heteroatoms (nitrogen, oxygen, or sulfur) can be viewed with long-and short-wave ultraviolet light. The unaided eye can see other material, or the plates can be developed in iodine. Iodine has an affinity for most petroleum compounds, including the saturated hydrocarbons, and stains the compounds a reddish-brown color. 

Underestimating the overall risk from petroleum hydrocarbons due to missing significant amounts of some of the compounds of most concern (e.g., polynuclear aromatic hydrocarbons). 

Pentagone is an aqueous-based surface decontamination product developed for the cleanup of pentachlorophenols, creosote, petroleum hydrocarbons, chlorinated hydrocarbons, polynuclear aromatic hydrocarbons, and selected pesticide and herbicide spills. It can be used on concrete, asphalt, or metal and is capable of being applied as a foam, allowing treatment of overhead, vertical, and horizontal surfaces. It has been commercially available since 1993 and has been used in multiple applications. 

According to the technology developer, the technology treats petroleum-contaminated soils, hazardous wastes, heavy metals, polychlorinated biphenyls (PCBs), semivolatUe organic compounds (SVOCs), volatile organic compounds (VOCs), polynuclear aromatic hydrocarbons (PAHs), and pesticides. 

The SBP slurry-phase bioremediation system can treat a wide range of organic contamination, especially wood-preserving wastes and solvents. A modified version can also treat polynuclear aromatic hydrocarbons (PAHs) such as creosote and coal tar pentachlorophenol (PCP) total petroleum hydrocarbons (TPH) and chlorinated aliphatics, such as trichloroethene (TCE). The technology can be combined with SBP s membrane filtration system to form a soil cleaning system to handle residuals and contaminated liquids. 

Solid-phase bioremediation is an ex situ treatment technology for soil and sediment contaminated with total petroleum hydrocarbons (TPH), polynuclear aromatic hydrocarbons (PAHs), and phenols, including pentachlorophenol (PCP). 

The Biolift reactor has been used to treat soils contaminated with benzene, toluene, ethylbenzene, and xylene (BTEX), total petroleum hydrocarbons (TPHs), and polynuclear aromatic hydrocarbons (PAHs). The process uses microorganisms to oxidize organic compounds, yielding innocuous by-products. 

The identifiable compounds in coke-oven and petroleum pitches are mainly polynuclear aromatic hydrocarbons. Proton magnetic resonance spectra of solvent-soluble fractions of these materials show that over 90 of the protons are attached to aromatic rings. Under the conditions of carbonization it would... 

In late 1989, Minnesota tested tires for leachate and found that leaching of heavy metals, polynuclear aromatic hydrocarbons, and total petroleum hydrocarbons from tire chips could not be completely ruled out (38). Now the preferred method is to use wood chips below the water table and tire chips above the wood chips. This is expected to extend the life of the fill over using just wood chips, since wood chips degrade in the unsaturated zone. 

Analytical Properties Separation of polynuclear aromatic hydrocarbons (of the type often encountered in petroleum residue work) by donor-acceptor complex formation Reference 5, 6... 

Isomers of xylene,93 ethyl benzene94 and nitrotoluene95 have been separated using cydodextrins. Individual components of petroleum fractions, such as polynuclear aromatic hydrocarbons, have been identified and quantified using cyclodextrin.96,97... 

The collected samples have been initially characterized for polynuclear aromatic hydrocarbons. The results indicate that there is a wider spectrum of polynuclear aromatic hydrocarbons present when SRC-II is combusted than is present when No. 2 fuel oil is combusted. In addition, the petroleum combustion gases contained significant amounts of saturated hydrocarbons, which were present at low levels or absent when SRC-II was combusted. The petroleum combustion gases also contained other compounds, as yet unidentified, that were not present when SRC-II was combusted. In both combustion experiments, the organics in the duct appear to be similar to those in the fuel being combusted. The vapors collected... 

As may be apparent from many of the examples presented above, models of processes that affect the fate and transport in groundwater of petroleum hydrocarbons and chlorinated aliphatic hydrocarbons are much more prevalent than models of other contaminants. Much research has yet to be accomplished to improve our understanding and ability to model transformation processes, particularly for contaminants like polynuclear aromatic hydrocarbons, nitro-aromatics, and pesticides. 

Although the great majority of petroleum and coal-based pitch materials, as well as model compounds such as polyvinyl chloride, acenaphthylene, decacyclene and polynuclear aromatic hydrocarbons, form anisotropic graphitizable carbons, it is an almost impossible task to predict the type of optical texture of a coke from an elemental analysis of the pitch. The size, shape and reactivity of peri-condensed polynuclear aromatic molecules in the products of pyrolysis of a pitch play a more important role in determining optical texture. 

Petroleum coke is a chunky powdered carbon product derived from petroleum. If petroleum coke is heated to a high temperature, it may emit volatiles such as polynuclear aromatic hydrocarbons, which could be suspect carcinogens. Such exposures can occur in coke oven workers. 

An example of how transport impacts effects on the body can be seen from a consideration of benzo [a] pyrene (BaP). BaP is a polynuclear aromatic hydrocarbon (PAH) that is a component of petroleum and cigarette smoke. It is an established lung carcinogen, but it is BaP s diol-epoxide metabolite that is the actual tumerogen. The path from absorption to tumor production is a five-step process involving two transport steps. The five steps, which are depicted in Fig. 4.1 are ... 

Pancirov, R. J. and R. A. Brown. 1975. Analytic methods for polynuclear aromatic hydrocarbons in crude oils, heating oils, and marine tissues. In Proceedings of the 1975 Conference on Prevention and Control of Oil Pollution, March 25-27, 1975. San Francisco, CA. American Petroleum Institute Washington, DC., 103-114. 

Fluorescence and GC/MS analyses show Chat carbonized coal hydrocarbons are widespread contaminants of sediments In the Elizabeth River, Norfolk, Va. The highest levels are found In the vicinity of suspected sources and generally decrease with Increased distance from these sources. Parent aromatic compounds are the predominant hydrocarbon component of carbonized coal and can be uniquely detected even In the presence of petroleum hydrocarbons. Carbonized coal products are a chronic source of priority pollutant polynuclear aromatic hydrocarbons in the Elizabeth River. 

Brown RA, Weiss FT. 1978. Fate and effects of polynuclear aromatic hydrocarbons in the aquatic environment. Washington, D.C American Petroleum Institute. Publication no. 4297. 

Carver JH, Machado ML, MacGregor JA. 1986. Application of modified salmonella/microsome prescreen to petroleum-derived complex mixtures and polynuclear aromatic hydrocarbons (PAHs). Mutat Res 174 247-253. 

Renal effects were also noted in a study conducted by Deelman (1962), in which mice were exposed dermally to an unspecified amount of tar applied 6-18 times over 6-7 weeks. "Seriously affected" kidneys were noted, although no details or data were presented. Ten groups of Swiss albino mice received topical applications of 10% benzene solutions of eight petroleum asphalts of known polynuclear aromatic hydrocarbon content (Wallcave et al. 1971). An additional group of 15 males and females were painted with benzene only and served as controls. Zones of approximately 1 square inch were shaved in the skin of the back of each animal and the solutions of asphalt were painted in this area 2 times/week with 25 mL of solution (approximately 2.5 mg asphalt per treatment). Amyloidosis was frequently observed in animals receiving asphalt, particularly in the kidney. The potential effect of benzene on the dermal absorption of asphalt components was not evaluated in this study. 

Wallcave L, Garcia H, Feldman R, et al. 1971. Skin tumorigenesis in mice by petroleum asphalts and coal-tar pitches of known polynuclear aromatic hydrocarbon content. Toxicol Appl Pharmacol 18 41-52. 

Arpino PJ, Ignatiadis I, de Ryke G (1987) Sulphur-containing polynuclear aromatic hydrocarbons from petroleum. Examination of their possible statistical formation in sediments. J Chromat 390, 329-348. 

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