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Application of some physical organic chemistry models to the study of oil spills residues in Patagonian soils
Author(s) -
Nudelman N. Sbarbati,
Ríos Stella M.,
Katusich Ofelia
Publication year - 2008
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/poc.1335
Subject(s) - chemistry , solvophobic , soil water , oil spill , sorption , desorption , environmental chemistry , solvent , asphalt , organic chemistry , analytical chemistry (journal) , soil science , adsorption , petroleum engineering , geology , cartography , geography
The present study focuses on the application of some physical organic chemistry (POC) models for a better understanding of the interactions between oil spills and soil. By studying the sorption behavior of pure compounds, it was possible to examine the application of the multilayer model to the prediction of crude oil isotherms. The difference between the predicted and experimental oil isotherms was only 13%, which indicates the reliability of the model. The distribution coefficients, K d , of soil samples containing oil residuals of different ages, were also determined using methanol as a co‐solvent. Desorption experiments showed that they are a function of the polarity of the liquid phases; the K d s, calculated by applying a model derived from the solvophobic theory, increase with increasing age. On the other hand, the natural attenuation of oil spills was studied by using GC and 1 H NMR techniques. Signals for four types of aliphatic and for the aromatic protons were clearly assigned; signals for alcohol (O H ) and carboxylic (COO H ) protons were also observed; compounds exhibiting these polar groups are usually not detected in the GC–FID conventional analysis. The principal component analysis (PCA) of K d , and the parameters determined by GC and NMR, showed that the first and second PC, accounted for more than 95 and 81% of variance, for NMR and GC parameters, respectively. The detailed results suggest that the 1 H NMR data would be more useful than GCs to evaluate the environmental transformations that oil spills undergo in Patagonian soils. Nevertheless, direct extrapolation of the present results to other environments is not possible because the changes depend strongly on the original chemical composition of the crude oil and the variable exposure conditions along the time. Copyright © 2008 John Wiley & Sons, Ltd.