Volatile chemicals, spills

Some evidence such as burn char patterns, surface fractures, or volatile chemicals spills can degrade as a result of weather conditions (rain, wind, or sunlight)... 

Weirick, M. L., S. M. Farquhar, and B. P. Chismar (1994). Spill Containment and Destruction of a Reactive, Volatile Chemical. Process Safety Progress 13,2 (April), 69-71. 

Greer, J. S., and S. S. Gross. 1980. The Practicality of Controlling Vapor Released from Spills of Volatile Chemicals through Cooling Control of Hazardous Material Spills. Proceedings of National Conference, pp. 130-133. Nashville, TN Vanderbilt University. 

Petroleum distillates that are spilled onto the ground may migrate to, and contaminate, groundwater supplies. Because they are volatile chemicals, however, most environmental releases will ultimately end up migrating to the atmosphere. 

An estimate of travel time is important in many situations. For example, a municipal water supply operator needs to know how long it will take a chemical spilled upriver to reach downstream water intake pipes so that the valves can be closed before the spilled chemical arrives. An estimate of travel time is also necessary when calculating whether processes such as loss to the air (volatilization) or bacterial degradation will significantly decrease a chemical concentration along a reach of river. 

If the contaminant sorbates are relatively, i.e., with boiling points less than 200°C, quite effective regeneration can be achieved using steam. This process can be carried out either in situ, using the fixed bed column system, or by removing the spent adsorbent (for example, after batch adsorber filtration) to a furnace-type regeneration system. The contaminant-laden steam can then be condensed at a suitable temperature to condense and recover the volatiles from the chemical spill. Further separation can be appUed if necessary, such as distillation. 

Llompart, M., K. Li, and M. F. Fingas. 1997a. The Application of Solid Phase Micro Extraction (SPME) for Spill Emergency Work, Part 1 HS-SPME Analysis of Volatiles and Semi-volatiles in Soil, in Proceedings of the Fourteenth Technical Seminar on Chemical Spills, Environment Canada, Ottawa, ON, pp. 83-91. 

In addition to these common sources from consumer products, chemicals can also volatilize from the soil and groundwater beneath structures into indoor air, as shown in figure 10.6. These volatile chemicals are present in the subsurface from releases associated with industrial activities, including leaking underground fuel tanks (e.g., benzene, MTBE, and other petroleum-related chemicals), surface spills (followed by downward percolation of chemicals to groundwater and lateral transport beneath structures), and other environmental releases. 

Volatilization of ionic liquids from soils and sediments has not been measured. The envi-rorunental properties that affect volatilization of any solvent are its vapor pressure, solubility in water and the properties of the soil such as organic matter content and texture. " In the absence of measured data, there are numerous methods to estimate the likely extent of volatilization of a solvent following, for example, a chemical spill. However, as discussed in Section 16.2.4.2, the vapor pressure of typical ionic liquids is negligible suggesting that volatilization from dry or wet soil would be insignificant. 

Stripping of these compounds which can then be concentrated by adsorption on activated carbon for subsequent disposal. From a safety standpoint, if a volatile hazardous chemical is spilled, the concern over inhalation exposure may warrant the need for respirators. 

Mass chromatography of mlz 146 and 148 and mlz 180 and 182 is shown to be highly selective for di- and trichlorobenzenes. These components are only present in relatively minor amounts. A mass chromatogram at mlz 88 showed the presence of the rather volatile compound dioxane. This sediment sample obviously is heavily polluted with non-biodegraded mineral oil fractions and a number of other components (i.e. stearic acid, chlorinated benzenes), which point to spills of numerous bulk chemicals. 

Several soil-vapor monitoring techniques are currendy being used to define areas of volatile organic chemical contamination. These procedures usually involve the collection of representative samples of the soil gas for analysis of indicator compounds. Maps marked with concentration contours of these indicator compounds can be used to identify potential sources to delineate the contaminated area. Indicator compounds (usually the more volatile compounds) are selected for each specific situation. For gasoline contamination, the compounds are usually benzene, toluene, ethylbenzene, and total xylene (BTEX). In the case of a fuel oil spill, the most commonly used indicator is naphthalene. Some laboratories have adapted the laboratory procedures used for quality analysis of wellhead condensate (i.e., normal paraffins) to include light-end (<8 carbons) molecular analysis. 

In the same vein, certain waste-handling procedures, even those performed intermittently, can result in very serious contaminant exposure without proper precautions. Workers need to be instructed in the proper procedures for cleaning up spills and accumulated debris. Spilled materials can become airborne and pose an inhalation hazard. Spills and chemical process wastes may end up in the waste-water treatment facilities where they again can be volatilized into the air and result in unexpected worker exposure. 

Spills of many chemicals found in urban areas (including petroleum and fuel oils) are also a source of contamination of both groundwaters and surface waters. The volatile components of petroleum oils may penetrate some types of plastic water pipes if these chemicals contaminate the ground surrounding the pipe. Choice of materials for water distribution should take into account such risks and should consider whether pipes are to be laid through contaminated ground. 

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