Light nonaqueous phase liquids LNAPLs

Fig. 4.7 Simplified conceptual model for Light nonaqueous phase liquid (LNAPL) release and migration. Reprinted from Mercer JW, Cohen RM (1990) A review of immiscible fluids in the subsurface Properties, models, characterization, and remediation. J Contam Hydrol 6 107-163. Copyright 1990 with permission of Elsevier...

The contaminant s aqueous solubility and density greatly influence its final disposition in water-solid systems. Dense nonaqueous phase liquids (DNAPLs) are chemicals with densities greater than water and typically low aqueous solubilities. DNAPLs naturally partition away from the aqueous phase and towards the solid phase, often pooling on top of an impermeable solid layer. On the other hand, light nonaqueous phase liquids (LNAPLs) possess densities less than water and have a tendency to pool on the water s surface where they may be prone to volatilization and photolysis reactions. Various liquid-solid partition coefficients have been... 

Nonaqueous-Phase Liquid. (NAPL) Any liquid other than water. In environmental fields the term commonly refers to hydrocarbon liquids less dense than water (light nonaqueous-phase liquid, LNAPL), or chlorinated hydrocarbons that are more dense than water (dense nonaqueous-phase liquid, DNAPL). Example 1,1,1-trichloroethane is a DNAPL. 

Many contaminants exist as immiscible nonaqueous phase liquids (NAPLs) in soil. These liquids do not fully solubilize in water and exist as a separate phase due to physical and chemical differences from water. NAPLs can be classified as light (less dense than water) nonaqueous phase liquids (LNAPLs) and dense (more dense than water) nonaqueous phase liquids (DNAPLs). A list of typical NAPLs and their important properties is presented in Table 8.8. As described elsewhere in this book (Chapter 15), NAPLs may solubilize, volatilize, and otherwise partition among phases. This section focuses on the advective transport of pure-phase NAPL. 

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