Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9452067 | Chemosphere | 2005 | 11 Pages |
Abstract
This study compares in situ observed porewater concentration of persistent organic pollutants (POPs) with predictions by common solid-water phase distribution models. Bottom sediments were sampled in The Grenlandsfjords, Norway, and the interstitial porewater was isolated from the solids by centrifugation and filtration. Both phases were analysed for polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F), polycyclic aromatic hydrocarbons (PAH), and organic carbon. Based on the sediments' solid phase content of POPs, organic carbon, and soot carbon, we used the organic matter partitioning (OMP), and also the soot and organic matter partitioning (SOMP) model to estimate the porewater concentration. The OMP model gave better agreement to observations than the SOMP model for both PCDD/Fs and PAHs. The observed concentration of the PCDD/Fs in the sediments' porewater was much higher than in the deep water of the fjord. The logarithm of the organic matter-water partitioning coefficent (log KOC) in the porewater had positive linear regression on the logarithm of the octanol-water partitioning coefficient (log KOW). The slope of the regression model was indistinguishable from 1, except for the PAHs as a group which had a slope less than 1. This contrasts to previous studies undertaken in The Grenlandsfjords water column, where the slopes were higher than 1 for PCDD/Fs, and the KOC were much higher than the KOW. One explanation may be that the influence of POPs adsorption to soots decrease because competitive sorption by other compounds in the sediment are higher than in the water column. This indicates that the sorption isotherms for these POPs need better understanding in order to be applicable in both the water column and the porewater.
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Environmental Chemistry
Authors
N. Johan Persson, Thomas D. Bucheli, Ãrjan Gustafsson, Dag Broman, Kristoffer Næs, Rasha Ishaq, Yngve Zebühr,