Oren Adi, Chefetz Benny
Department of Soil and Water Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, The Hebrew University of Jerusalem, P.O. Box 12, Rehovot 76100, Israel.
Chemosphere. 2005 Sep;61(1):19-29. doi: 10.1016/j.chemosphere.2005.03.021. Epub 2005 Apr 25.
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.
以以色列基顺河上下游站点的全沉积物、腐殖酸（HA）和胡敏素样品为研究对象，研究了菲和萘的吸附与解吸行为。13C核磁共振光谱和吸附系数表明，沉积物有机质的芳香族和脂肪族部分均发生吸附作用，且刚性链烷烃区域可能导致吸附的非线性。河流下游区域全沉积物和胡敏素样品中两种吸附质的碳归一化弗罗因德利希亲和值显著高于上游沉积物样品。根据测得的亲和值，吸附剂可按以下顺序排列：胡敏素>腐殖酸>全沉积物。与其他吸附剂相比，菲从全沉积物样品中的解吸率最低。对于萘，全沉积物和胡敏素样品的解吸滞后现象相似：二者均表现出随着溶质浓度降低解吸减少。下游沉积物中所有有机组分的较高吸附亲和力被认为与低水平的极性区域和胡敏素含量有关。研究得出结论，在大量沉积物样品中，HA组分对短期吸附的总体贡献非常重要，但吸附的非线性主要由胡敏素络合物控制。全沉积物样品记录的低解吸潜力可能会影响吸附的疏水性有机化合物的自然衰减。
