| 1. |
- Arp, Hans Peter H., et al.
(författare)
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Review of polyoxymethylene passive sampling methods for quantifying freely dissolved porewater concentrations of hydrophobic organic contaminants
- 2015
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Ingår i: Environmental Toxicology and Chemistry. - : Wiley. - 0730-7268 .- 1552-8618. ; 34:4, s. 710-720
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Forskningsöversikt (refereegranskat)abstract
- Methods involving polyoxymethylene (POM) as a passive sampler are increasing in popularity to assess contaminant freely dissolved porewater concentrations in soils and sediments. These methods require contaminant-specific POM-water partition coefficients, K-POM. Certain methods for determining K-POM perform reproducibly (within 0.2 log units). However, other methods can give highly varying K-POM values (up to 2 log units), especially for polycyclic aromatic hydrocarbons (PAHs). To account for this variation, the authors tested the influence of key methodological components in K-POM determinations, including POM thickness, extraction procedures, and environmental temperature and salinity, as well as uptake kinetics in mixed and static systems. All inconsistencies in the peer-reviewed literature can be accounted for by the likelihood that thick POM materials (500m or thicker) do not achieve equilibrium (causing negative biases up to 1 log unit), or that certain POM extraction procedures do not ensure quantitative extraction (causing negative biases up to 2 log units). Temperature can also influence K-POM, although all previous literature studies were carried out at room temperature. The present study found that K-POM values at room temperature are independent (within 0.2 log units) of POM manufacture method, of thickness between 17m and 80m, and of salinity between 0% and 10%. Regarding kinetics, monochloro- to hexachloro-polychlorinated biphenyls (PCBs) were within 0.2 log units of equilibrium after 28d in the mixed system, but only dichloro-PCBs achieved near equilibrium after 126d in the static system. Based on these insights, recommended methods and K-POM values to facilitate interlaboratory reproducibility are presented.
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| 2. |
- Samuelsson, Göran S., et al.
(författare)
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Reduced bioaccumulation of PCBs and PAHs by sediment fauna following in situ remediation with activated carbon in Trondheim Harbor (Norway)
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- Thin-layer capping with activated carbon (AC) was deployed in experimental plots in Trondheim harbor, Norway, using caps containing AC+clay, AC-only or AC+sand. Intact sediment cores were collected from the in situ remediated plots to study the capping efficiency of the various AC treatments in reducing the aqueous concentrations and the bioaccumulation of polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs) in the polychaete Hediste diversicolor and the clam Abra nitida. Reduced aqueous concentrations were observed in all AC-treatments, but generally AC+clay appeared to be superior to the other tested treatments. Capping efficiency by AC+clay, in terms of reduced bioaccumulation of PAHs and PCBs, ranged between 40 % and 87% in the worms and between 67% and 97% in the clams. Sediment capped with AC-only also led to reduced bioaccumulation of PCBs, while AC+sand showed no reduction in bioaccumulation. The worms had lower relative lipid content in the AC-only treatment after exposure.
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