Hydrophobic

Hydrophobic refers to the tendency of a substance to repel water or to be incapable of completely dissolving in water. Hydrophobic substances, such as hydrocarbons and organochlorine pesticides ( DDT is an example) are readily soluble in many nonpolar solvents, such as octanol, but only sparingly soluble in water, a polar solvent.

The hydrophobicity of an organic contaminant is one of the factors that determines the fate of the contaminant in the environment. In general the more hydrophobic a contaminant is the more likely you will find it associated with nonpolar organic matter such as humic substances and lipids (fats). The association of a contaminant with natural-organic matter can be predicted fairly well by the octanol-water partition coefficient (K_OW) of the contaminant, which in turn can be used to predict the extent the contaminant will bioaccumulate.

More Information

• Landmark Book Published on the Fate of Contaminants in the Environment: Partition and Adsorption of Organic Contaminants in Environmental Systems

References

• Chiou, C.T., 2002, Partition and adsorption of organic contaminants in environmental systems: New York, John Wiley & Sons, Inc., 257 p.
• Stumm, W., and Morgan, J.J., 1981, Aquatic chemistry—An introduction emphasizing chemical equilibria in natural waters: New York, John Wiley and Sons, 2nd edition, 780 p.
• The American Heritage Dictionary of the English Language, 2000: Houghton Mifflin Company, Fourth Edition.

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