High molecular weight and strongly hydrophobic organic contaminants partition into soils containing which component?

High molecular weight and strongly hydrophobic organic contaminants partition into soils containing which component?

• A. Silicate Clay
• B. Humic Matter
• C. Sand
• D. Gravel

Answer: (B)

High molecular weight and strongly hydrophobic organic contaminants prefer nonpolar, carbon-rich domains, so they partition into soils that contain substantial organic matter, especially humic matter. Humic substances provide large, hydrophobic regions formed from complex, highly conjugated carbon structures that interact strongly with nonpolar contaminants, yielding strong sorption and reduced mobility. Mineral components like silicate clay, sand, or gravel are more polar or charged and offer fewer nonpolar sorption sites, so they don’t retain these big hydrophobic molecules as effectively. In short, the soil’s organic carbon content, and particularly humic matter, governs the sorption of these contaminants.

High molecular weight and strongly hydrophobic organic contaminants prefer nonpolar, carbon-rich domains, so they partition into soils that contain substantial organic matter, especially humic matter. Humic substances provide large, hydrophobic regions formed from complex, highly conjugated carbon structures that interact strongly with nonpolar contaminants, yielding strong sorption and reduced mobility. Mineral components like silicate clay, sand, or gravel are more polar or charged and offer fewer nonpolar sorption sites, so they don’t retain these big hydrophobic molecules as effectively. In short, the soil’s organic carbon content, and particularly humic matter, governs the sorption of these contaminants.