TY - JOUR
T1 - Sorption-desorption behavior of polycyclic aromatic hydrocarbons in upstream and downstream river sediments
AU - Oren, Adi
AU - Chefetz, Benny
N1 - Funding Information:
This research was supported in part by The Max Deutsch Foundation for Water Research.
PY - 2005/9
Y1 - 2005/9
N2 - Sorption and desorption behaviors of phenanthrene and naphthalene were studied with the whole sediment, humic acid (HA) and humin samples from downstream and upstream sites along the Kishon River, Israel. The 13C nuclear magnetic resonance spectra and the sorption coefficients suggest that sorption occurs to both aromatic and aliphatic moieties of the sedimentary organic matter and that rigid paraffinic domains probably contribute to the sorption non-linearity. The carbon-normalized Freundlich affinity values for the two sorbates were significantly higher for the whole sediment and humin samples from the downstream region of the river than for the upstream sediment samples. On the basis of the measured affinity values, the sorbents can be arranged in the following order: humin > HA > whole sediment. Phenanthrene exhibited the lowest desorption from the whole sediment samples compared with the other sorbents. For naphthalene, the desorption hysteresis obtained with the whole sediment and humin samples were similar: both exhibited a decrease in desorption with decreasing solute concentration. The higher sorption affinities observed for all the organic fractions from the downstream sediment are suggested to be related to the low levels of polar domains and humin content. It is concluded that in bulk sediment samples, the overall contribution of the HA fraction to short-term sorption is of high importance, but the sorption non-linearity is controlled mainly by the humin complexes. The low desorption potential recorded for the whole sediment samples could affect the natural attenuation of the sorbed hydrophobic organic compounds.
AB - Sorption and desorption behaviors of phenanthrene and naphthalene were studied with the whole sediment, humic acid (HA) and humin samples from downstream and upstream sites along the Kishon River, Israel. The 13C nuclear magnetic resonance spectra and the sorption coefficients suggest that sorption occurs to both aromatic and aliphatic moieties of the sedimentary organic matter and that rigid paraffinic domains probably contribute to the sorption non-linearity. The carbon-normalized Freundlich affinity values for the two sorbates were significantly higher for the whole sediment and humin samples from the downstream region of the river than for the upstream sediment samples. On the basis of the measured affinity values, the sorbents can be arranged in the following order: humin > HA > whole sediment. Phenanthrene exhibited the lowest desorption from the whole sediment samples compared with the other sorbents. For naphthalene, the desorption hysteresis obtained with the whole sediment and humin samples were similar: both exhibited a decrease in desorption with decreasing solute concentration. The higher sorption affinities observed for all the organic fractions from the downstream sediment are suggested to be related to the low levels of polar domains and humin content. It is concluded that in bulk sediment samples, the overall contribution of the HA fraction to short-term sorption is of high importance, but the sorption non-linearity is controlled mainly by the humin complexes. The low desorption potential recorded for the whole sediment samples could affect the natural attenuation of the sorbed hydrophobic organic compounds.
KW - C NMR
KW - Desorption hysteresis
KW - Humic acid
KW - Humin
KW - Sedimentary organic matter
UR - http://www.scopus.com/inward/record.url?scp=24644484016&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2005.03.021
DO - 10.1016/j.chemosphere.2005.03.021
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C2 - 16157166
AN - SCOPUS:24644484016
SN - 0045-6535
VL - 61
SP - 19
EP - 29
JO - Chemosphere
JF - Chemosphere
IS - 1
ER -