Flashcard library · Environmental Science · PaperFren

Hydrophilic freshwater DOM biodegrades fastest

Across a Swedish stream and two lakes, the most water-loving DOM fractions lost 12–25% of DOC in 150 days versus 6–15% for hydrophobic fractions.

Keep what you just learned

Save these 11 cards to your NoteFren library. Your first review starts right away, and each card links back to the study it came from.

What was the hypothesis?

The most hydrophilic DOM fractions would be the most biodegradable.

Which waters were sampled?

A humic stream, a clearwater lake, and a eutrophic lake in Uppland, Sweden.

How was hydrophobicity separated?

C18-bonded silica chromatography retaining hydrophobic species more.

Which fractions were most labile?

The most hydrophilic fractions (U and 1).

DOC loss for hydrophilic fractions at day 150?

12–25% DOC loss (k ≥ 0.005).

DOC loss for hydrophobic fractions?

6–15% DOC loss (k < 0.005); most refractory.

Did the pattern depend on site type?

No: the hydrophilic-most-labile result was common for all three sites.

What is the dilution hypothesis?

Compounds persist because each slightly different substrate is vanishingly dilute.

Why can MS miss hydrophilic DOM?

Extraction and electrospray ionization exclude the most hydrophilic fraction.

Incubation length?

150 days with repeated DOC sampling.

Did pooled fractions show strong priming?

Not a consistent interactive effect across all three sites.