| 1. |
- Gunnarsson, Jonas S., et al.
(författare)
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Response of marine benthic fauna to thin-layer capping with activated carbon in a large-scale field experiment in the Grenland fjords, Norway
- 2017
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 24:16, s. 14218-14233
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Tidskriftsartikel (refereegranskat)abstract
- A field experiment with thin-layer capping was conducted in the Grenland fjords, Norway, for remediation in situ of mercury and dioxin-contaminated sediments. Experimental fields at 30 and 95 m depth were capped with (i) powdered activated carbon (AC) mixed with clay (AC+clay), (ii) clay, and (iii) crushed limestone. Ecological effects on the benthic community and species-feeding guilds were studied 1 and 14 months after capping, and a total of 158 species were included in the analyses. The results show that clay and limestone had only minor effects on the benthic community, while AC+clay caused severe perturbations. AC+clay reduced the abundance, biomass, and number of species by up to 90% at both 30 and 95 m depth, and few indications of recovery were found during the period of this investigation. The negative effects of AC+clay were observed on a wide range of species with different feeding strategies, although the suspension feeding brittle star Amphiura filiformis was particularly affected. Even though activated carbon is effective in reducing sediment-to-water fluxes of dioxins and other organic pollutants, this study shows that capping with powdered AC can lead to substantial disturbances to the benthic community.
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| 2. |
- Raymond, Caroline, et al.
(författare)
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Impaired benthic macrofauna function 4 years after sediment capping with activated carbon in the Grenland fjords, Norway
- 2021
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Ingår i: Environmental Science and Pollution Research. - : Springer Science and Business Media LLC. - 0944-1344 .- 1614-7499. ; 28, s. 16181-97
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Tidskriftsartikel (refereegranskat)abstract
- The sediments in the Grenland fjords in southern Norway are heavily contaminated by large emissions of dioxins and mercury from historic industrial activities. As a possible in situ remediation option, thin-layer sediment surface capping with powdered activated carbon (AC) mixed with clay was applied at two large test sites (10,000 and 40,000 m(2)) at 30-m and 95-m depths, respectively, in 2009. This paper describes the long-term biological effects of the AC treatment on marine benthic communities up to 4 years after treatment. Our results show that the capping with AC strongly reduced the benthic species diversity, abundance, and biomass by up to 90%. Vital functions in the benthic ecosystem such as particle reworking and bioirrigation of the sediment were also reduced, analyzed by using novel bioturbation and bioirrigation indices (BPc, BIPc, and IPc). Much of the initial effects observed after 1 and 14 months were still present after 49 months, indicating that the effects are long-lasting. These long-lasting negative ecological effects should be carefully considered before decisions are made on sediment remediation with powdered AC, especially in large areas, since important ecosystem functions can be impaired.
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| 3. |
- Josefsson, Sarah, et al.
(författare)
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Capping Efficiency of Various Carbonaceous and Mineral Materials for In Situ Remediation of Polychlorinated Dibenzo-p-dioxin and Dibenzofuran Contaminated Marine Sediments : Sediment-to-Water Fluxes and Bioaccumulation in Boxcosm Tests
- 2012
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 46:6, s. 3343-3351
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Tidskriftsartikel (refereegranskat)abstract
- The efficiency of thin-layer capping in reducing sediment-to-water fluxes and bioaccumulation of polychlorinated dibenzo-p-dioxins and dibenzofurans, hexachlorobenzene, and octachlorostyrene was investigated in a boxcosm experiment. The influence of cap thickness (0.5-5 cm) and different cap materials was tested using a three-factor experimental design. The cap materials consisted of a passive material (coarse or fine limestone or a marine clay) and an active material (activated carbon (AC) or kraft lignin) to sequester the contaminants. The cap thickness and the type of active material were significant factors, whereas no statistically significant effects of the type of passive material were observed. Sediment-to-water fluxes and bioaccumulation by the two test species, the surface-dwelling Nassarius nitidus and the deep-burrowing Nereis spp., decreased with increased cap thickness and with addition of active material. Activated carbon was more efficient than lignin, and a ∼90% reduction of fluxes and bioaccumulation was achieved with 3 cm caps with 3.3% AC. Small increases in fluxes with increased survival of Nereis spp. indicated that bioturbation by Nereis spp. affected the fluxes.
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| 4. |
- Näslund, J., et al.
(författare)
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Ecosystem effects of materials proposed for thin-layer capping of contaminated sediments
- 2012
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Ingår i: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 449, s. 27-U46
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Tidskriftsartikel (refereegranskat)abstract
- Ecotoxicological effects of 2 carbonaceous and 7 mineral capping materials suggested for in situ remediation of contaminated sediments in the Grenland fjords, Norway, were investigated in a mesocosm experiment. The primary objective was to compare the various materials with regard to potentially harmful effects on the benthic ecosystem. The materials assessed were activated carbon, Kraft-lignin, sand and clay materials, and 3 industrial by-products. Using sediment box-core samples with intact benthic communities, effects on structural (bacterial, macro-and meiofauna diversity) and functional (sediment-to-water nutrient fluxes, oxygen fluxes and bacterial production) endpoints were assessed. Significant deviations from the control (no capping) were detected for all of the tested materials for at least one endpoint. Generally, materials similar to the indigenous sediment (clay, sand) had relatively low deviations from the control, whereas industrial products (plaster, 2 types of crushed marble) resulted in deviations for most endpoints and large reductions in community richness and abundance. For example, at the end of the experimental period, the number of macrofauna taxa was <10 in these treatments, compared to >27 in uncapped mesocosm and field control sediments. The results from the study show that reducing harmful ecosystem effects from thin-layer capping by selecting capping materials based on robust, multi-endpoint mesocosm bench-tests is both possible and recommendable. Potential ecosystem impacts are particularly important to consider when large areas and areas with adequate ecological status are considered for thin-layer capping.
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| 5. |
- Samuelsson, Göran S., et al.
(författare)
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Capping in situ with activated carbon in Trondheim harbor (Norway) reduces bioaccumulation of PCBs and PAHs in marine sediment fauna
- 2015
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Ingår i: Marine Environmental Research. - : Elsevier BV. - 0141-1136 .- 1879-0291. ; 109, s. 103-112
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Tidskriftsartikel (refereegranskat)abstract
- Three types of thin-layer caps with activated carbon (AC) were tested in situ in experimental plots (10 x 10 m) in Trondheim harbor, Norway, using AC + clay, AC-only or AC + sand. One year after capping, intact sediment cores were collected from the amended plots for ex situ surveys of the capping efficiency in reducing the PAH and PCB aqueous concentrations and bioaccumulation by the polychaete Hediste diversicolor and the clam Abra nitida. Reduced pore water concentrations were observed in all AC treatments. The capping efficiency was in general AC + clay > AC-only > AC + sand. AC + clay reduced bioaccumulation of PAH and PCB congeners 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. Thus the best thin-layer capping method in this study was AC mixed with clay.
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| 6. |
- Samuelsson, Göran S., 1967-
(författare)
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In situ remediation of contaminated sediments using thin-layer capping : efficiency in contaminant retention and ecological implications
- 2013
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Hydrophobic organic contaminants (HOCs) often reside in sediments sorbed to particles, most tightly to particles with high content of organic carbon. If persistent, such pollutants can accumulate in the sediment for many years and constitute a contamination risk for sediment-living organisms and organisms at higher trophic levels, including humans.Since traditional remediation techniques are associated with complications (e.g. release of contaminants during dredging operations, disturbance of benthic faunal communities), or constraints (handling of large amounts of contaminated sediment and water, limitations due to depth and size of the area, high costs), there is a need for new alternative methods.In situ remediation through thin-layer capping (a few centimeter cover) with a sorbing material such as activated carbon (AC) has been proposed as an alternative remediation method. Compared to traditional remediation techniques, AC amendment in a thin layer means less material handling and lower costs and is assumed to be less disruptive to benthic communities. The objectives of this thesis were to investigate the ecological effects from thin layer capping as well as the efficiency in contaminant retention.Thin layer capping amended with AC proved to reduce availability of HOCs to the tested organisms, the gastropod Nassarius nitidus (Paper II), the clam Abra nitida (Paper III) and to polychaete worms (Paper II and III). The remediation technique also decreased the sediment-to-water fluxes of the contaminants (Paper II and III).However, AC amended thin-layer capping was also found to cause negative biological effects. In laboratory studies with only a few species the negative effects were minor, or difficult to discern with the endpoints used (Paper II and III). In a larger multi-species mesocosm (boxcore) study, on the other hand, the negative effects were more prominent (Paper I) and in a large scale field study the benthic community was found to be profoundly disturbed by the AC amendment, with the effects persisting or even worsening ca one year (14 months) post amendment (Paper IV).
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| 7. |
- Samuelsson, Göran S., et al.
(författare)
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Large-scale field study on thin-layer capping of dioxin contaminated sediments in the Grenland fjords, Norway : Effects on marine benthic fauna
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Annan publikation (övrigt vetenskapligt/konstnärligt)abstract
- The Grenland fjords on the South East Coast of Norway are heavily contaminated with dioxins and furans after emissions from past industrial activities. Thin layer capping with a 1.1 to 3.7 cm cap was tested as a remediation option in a large-scale in situ study in two different parts of the fjord system, in the Ormefjord at 25-30 meters depth and in the Eidangerfjord at 80-100 meters depth. Three different capping materials: Limestone gravel, Clay, and powdered activated carbon (AC) mixed into clay (AC+clay) was compared to untreated reference fields in order to evaluate their effects on contaminant sequestering and possible effects on the benthic communities. Sediment to water fluxes of contaminants were significantly reduced by the capping materials, especially with AC-clay and is reported in a companion study.This study discusses the ecological effects of the remediation 1 and 14 months post treatment. Capping with Clay and Lime had minor and short-lasting effects on benthic fauna. Capping with AC+clay, however, had led to profound and more long-lasting perturbations of the macrofauna. An initial massive decline in filter feeders and suspension feeders was observed after 1 month in the shallower Ormefjord. The negative effects got worse after 14 months and resulted in dramatic reductions of all feeding guilds. The number of species, organism abundances and biomass in the AC+clay field were ca 80-90 % lower compared to the reference fields after 14 months.The negative effects were less pronounced at the deeper (80-100 meters) location in the Eidangerfjord and were also stable with time, suggesting that the benthic community the deeper habitat was more resilient to the capping compared to the shallower community in Ormefjord.The differences in response of the two communities are hypothesized to be due to the higher macrofaunal diversity in the deeper location, as well as to differences in abiotic factors such as available food and temperature. Results from this study show that amendment with powdered AC can lead to serious perturbations of the benthic community, at least initially, i.e. one year post capping in this study. These results stresses that further long-term monitoring of these benthic communities is necessary before capping with AC+clay could be advocated as a potential remediation option.
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| 8. |
- 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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| 9. |
- Cornelissen, Gerard, et al.
(författare)
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Remediation of Contaminated Marine Sediment Using Thin-Layer Capping with Activated Carbon-A Field Experiment in Trondheim Harbor, Norway
- 2011
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Ingår i: Environmental Science and Technology. - : American Chemical Society (ACS). - 0013-936X .- 1520-5851. ; 45:14, s. 6110-6116
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Tidskriftsartikel (refereegranskat)abstract
- In situ amendment of contaminated sediments using activated carbon (AC) is a recent remediation technique, where the strong sorption of contaminants to added AC reduces their release from sediments and uptake into organisms. The current study describes a marine underwater field pilot study in Trondheim harbor, Norway, in which powdered AC alone or in combination with sand or clay was tested as a thin-layer capping material for polycyclic aromatic hydrocarbon (PAH)-contaminated sediment. Several novel elements were included, such as measuring PAH fluxes, no active mixing of AC into the sediment, and the testing of new manners of placing a thin AC cap on sediment, such as AC+clay and AC+sand combinations. Innovative chemical and biological monitoring methods were deployed to test capping effectiveness. In situ sediment-to-water PAH fluxes were measured using recently developed benthic flux chambers. Compared to the reference field, AC capping reduced fluxes by a factor of 2-10. Pore water PAH concentration profiles were measured in situ using anew passive sampler technique, and yielded a reduction factor of 2-3 compared to the reference field. The benthic macrofauna composition and biodiversity were affected by the AC amendments, AC + clay having a lower impact on the benthic taxa than AC-only or AC + sand. In addition, AC + clay gave the highest AC recoveries (60% vs 30% for AC-only and AC + sand) and strongest reductions in sediment-to-water PAH fluxes and porewater concentrations. Thus, application of an AC-clay mixture is recommended as the optimal choice of the currently tested thin-layer capping methods for PAHs, and more research on optimizing its implementation is needed.
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| 10. |
- Hedman, Jenny E., et al.
(författare)
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Particle reworking and solute transport by the sediment-living polychaetes Marenzelleria neglecta and Hediste diversicolor
- 2011
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Ingår i: Journal of Experimental Marine Biology and Ecology. - : Elsevier BV. - 0022-0981 .- 1879-1697. ; 407:2, s. 294-301
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Tidskriftsartikel (refereegranskat)abstract
- This experimental study quantified and compared particle-mixing and solute transport by the polychaetes Marenzelleria neglecta (2 g ww, 3200 ind.m(-2)) and Hediste diversicolor (2 g ww, 800 ind.m(-2)) in Baltic Sea sediments. Particle tracers (luminophores) were added to the sediment surface and their vertical distribution in the sediment was measured after 10 d. The rate of particle mixing was quantified using a gallery-diffusion model calculating the biodiffusion coefficient D(b) and the non-local transport parameter r. Bioirrigation was measured by adding an inert solute tracer (bromide) to the overlying water 1, 1.5 and 2 d before the end of the experiment, and quantified by calculating the net bromide flux and fitting the bromide profiles to a 1D diffusion model providing an apparent biodiffusion coefficient D(a). The two polychaete worms displayed similar particle-mixing and solute transport efficiencies (based on total biomass) despite different modes of bioturbation. However, H. diversicolor was a more efficient particle-reworker and M. neglecta a more efficient bioirrigator, on an individual level. H. diversicolor buried a higher percentage (13%) of luminophores below the top 0.5 cm surface layer than M. neglecta (6%). D(b) did not differ between the two species (2.4 x 10(-3) cm(2) d(-1)) indicating a similar rate of diffusive mixing of the top sediment, however, the non-local transport parameter r was 2.5 y(-1) for H. diversicolor and zero for M. neglecta, suggesting no significant particle-transport below the biodiffusive layer by M. neglecta. The average individual net bromide fluxes obtained were ca. 0.01 mL min(-1) for H. diversicolor and 0.003 mL min(-1) for M. neglecta, corresponding to an area-specific rate of ca. 12 L m(-2) d(-1) at the used densities. D(a) did not differ between the two polychaetes, suggesting a higher individual solute exchange efficiency of M. neglecta considering the much higher ventilation rates reported for H. diversicolor than for Marenzelleria sp. The ongoing colonization of Baltic Sea sediments by M. neglecta at high densities may thus lead to an enhanced soluble release of both nutrients and contaminants. These results add information to the understanding of the potential effects of the invasion of M. neglecta on sediment biogeochemistry when competing with and/or replacing native species.
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