Laserfiche WebLink
r. <br /> r <br /> compounds are more likely to move into the vapor phase, and the <br /> r <br /> compounds that are both less volatile and more hydrophobic are <br /> more likely to remain in the free product or be adsorbed to soils <br /> (Hinchee and Reisinger 1987) . <br /> { Hydrocarbons not remaining in the free product willartit <br /> ion <br /> into either ground water or soil vapor and migrate as the result <br /> of a variety of interacting forces. In ground-water, contami- <br /> nants will migrate with the ground-water flow, interacting with <br /> the rock or soil geological medium, <br /> through a medium, organic constituents sinhthe omedium int pass <br /> eract <br /> < with the contaminants, and some are adsorbed or bound to part <br /> surfaces (Bruell and Hoa 1gg� Particle <br /> Hoag ) • The result is a net retardation <br /> in the velocity of movement of those compounds relative to that <br /> of the.ground water in which they are dissolved, The <br /> . analogous to laborator y chromatprocess is <br /> Chromatography. The compound with the <br /> least affinity for the porous medium is Least retarded and <br /> therefore moves most raidl <br /> P y. This compound, then, is present at <br /> the leading -edge> g .edge of a contaminant plume. <br /> x. <br /> The affinity of a Compound f <br /> Or the Soil Porous medium is <br /> function of the compound's hydrophobicit - Partly a <br /> 1 Y -that.. is, the more <br /> hydrophobic a compound the more likely it to adsorb to the <br /> solid medium. <br /> Aqueous solubility is a good indicator of hydro- <br /> phobicity: the more soluble a compound is, the less hydrophobic <br /> and more hydro <br /> it is, and vice versa. Vapor pressure is a <br /> good indicator of volatility; compounds with higher vapor <br /> pressures are more volatile. <br /> In determining the environmental fate of various hydrocarbon <br /> compounds in a._hydrocarbon -mixture:-such as ga <br /> have .a high vaporsoline, those which <br /> ' <br /> Pressure are more likely to move into the vapor <br /> Phase, or eva agate. <br /> P. Compounds: with high solubility are more <br /> likely to move into ground water <br /> from <br /> the <br /> f <br /> „ in round water, tend to move more ra idl. gee product and, once <br /> g � <br /> r P Y• Compounds of low <br /> vapor pressure and low solubility tend to remain in the free <br /> EXXON9:89L <br /> 9 <br /> , <br /> i - <br />