Fig. 2. Comparison of phenanthrene K_oc values with humic acid (HA) aromaticity. (A) Linear and (B) exponential correlations are tested for relationships between K_oc values and aromaticity. CHA, compost humic acid; PHA, peat humic acid; SHA, soil humic acid; U, untreated; H, hydrolysis; O, oximated; B, bleached; and S, subcritical water extracted.