Petroleum-contaminated media

EPA. 19931. Identification and Listing of Hazardous Waste, Exemption of Petroleum Contaminated Media and Debris. U.S. Environmental Protection Agency. 58 FR 8504. 

Analysis for total petroleum hydrocarbons (EPA Method 418.1) provides a one-number value of the petroleum hydrocarbons in a given environmental medium. It does not, however, provide information on the composition (i.e., individual constituents) of the hydrocarbon mixture. The amount of hydrocarbon contaminants measured by this method depends on the ability of the solvent used to extract the hydrocarbon from the environmental media and the absorption of infrared light (infrared spectroscopy) by the hydrocarbons in the solvent extract. The method is not specific to hydrocarbons and does not always indicate petroleum contamination, since humic acid, a nonpetroleum material and a constituents of many soils, can be detected by this method. 

The Therminator is an ex situ, commercially available medium-temperature portable thermal des-orption/destruction unit for soils and clays contaminated with petroleum hydrocarbons. According to the vendor, the Therminator offers an alternative to landfilling petroleum-contaminated soils. All information is from the vendor and has not been independently verified. 

Supercritical fluid extraction with carbon dioxide has been shown to be an excellent alternative to conventional solvent extraction for the removal of hydrocarbon pollutants from solid samples [4-7]. It is fast ( 30 minutes), nonpolluting, and relatively simple to implement. Additionally, recent work has shown that (supercritical fluid extraction using carbon dioxide is generally applicable to soil samples that have been contaminated with petroleum hydrocarbons ranging from those found in gasoline to those in medium crude oil (i.e., < C30) hydrocarbons) [8-10]. 

This profile covers total petroleum hydrocarbons (TPH), which is defined as the measurable amount of petroleum-based hydrocarbon in an environmental medium (Chapter 2). TPH is measured as the total quantity of hydrocarbons without identification of individual constituents. Sources of TPH contamination in the environment range from crude oil, to fuels such as gasoline and kerosene, to solvents, to mineral-based crankcase oil and mineral-based hydraulic fluids. These products contain not only a large number and variety of petroleum hydrocarbons, but also other chemicals that, strictly speaking, are not the subject of this profile, such as non-hydrocarbon additives and contaminants. The TPH issue is further complicated by the number of petroleum-derived hydrocarbons that have been identified—more than 250—and the variability in composition of crude oils and petroleum products (see Section 3.2 and Appendices D and E for details). 

Land farming has been used extensively to treat soils contaminated with petroleum hydrocarbons, pentachlorophenol (PCP), and polycyclic aromatic hydrocarbons (PAHs), and potentially could be used to treat low to medium concentrations of explosives as well. In land farming, soils are excavated to treatment plots and periodically rototilled to mix in nutrients,... 

Mobile nonpolar substances, as a rule, are liquid complex solutions. They exist independently of the subsurface water and rock and are capable of floating up and accumulating. Their composition is dominated first of all by alkane, naphthene and aromatic hydrocarbons with high molecular mass. At great depths they are represented by crude oils and at shallow depths their presence, as a rule, is associated with contamination of the geologic medium by petroleum products (gasoline, kerosene, residual oil, toluene, etc.). Most of their compounds in standard conditions and in pure form are in liquid and vapourous state. 

We have examined examples in which the formation of a dense deposit is accompanied by the formation of a loose deposit. Also possible are cases in which tacky and dense deposits are formed together, for example, in the combustion of residual fuel oil. The ash from residual fuel oil consists of metal corrosion products (iron salts and oxides), residues from substances used in the caustic and acid treatment of petroleum, salts from drilling water, contaminant particles, and particles of unburned carbon (soot and carboids). When the individual components of the ash interact with each other and with the gas medium, dense and tacky deposits are formed. Even though residual fuel oil combustion gives much less ash than is obtained in anthracite combustion, by a factor of 50 less than in peat combustion, by a factor of 100 and less than in shale combustion, by a factor of 200, the deposits formed by the fuel oil com-... 

Rao, S. M. 1991. Mechanistic evaluation of mitigation of petroleum hydrocarbon contamination by soil medium. Canadian Geotechnical Journal, 28, 84-91. 

---