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1.
Reg Environ Change ; 23(2): 69, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37153538

RESUMO

This paper explores how claims for transformative adaptation toward more equitable and sustainable societies can be assessed. We build on a theoretical framework describing transformative adaptation as it manifests across four core elements of the public-sector adaptation lifecycle: vision, planning, institutional frameworks, and interventions. For each element, we identify characteristics that can help track adaptation as transformative. Our purpose is to identify how governance systems can constrain or support transformative choices and thus enable targeted interventions. We demonstrate and test the usefulness of the framework with reference to three government-led adaptation projects of nature-based solutions (NBS): river restoration (Germany), forest conservation (China), and landslide risk reduction (Italy). Building on a desktop study and open-ended interviews, our analysis adds evidence to the view that transformation is not an abrupt system change, but a dynamic complex process that evolves over time. While each of the NBS cases fails to fulfill all the transformation characteristics, there are important transformative elements in their visions, planning, and interventions. There is a deficit, however, in the transformation of institutional frameworks. The cases show institutional commonalities in multi-scale and cross-sectoral (polycentric) collaboration as well as innovative processes for inclusive stakeholder engagement; yet, these arrangements are ad hoc, short-term, dependent on local champions, and lacking the permanency needed for upscaling. For the public sector, this result highlights the potential for establishing cross-competing priorities among agencies, cross-sectoral formal mechanisms, new dedicated institutions, and programmatic and regulatory mainstreaming. Supplementary Information: The online version contains supplementary material available at 10.1007/s10113-023-02066-7.

2.
Integr Environ Assess Manag ; 18(1): 99-107, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34019725

RESUMO

Nature-based solutions (NBS) can be used in combination with the reopening of piped rivers to support area development. In certain cases, piped rivers can run through disused landfills. This presents a complicating factor because landfills provide the possibility for river water to be contaminated by waste. In Skien municipality, close to Oslo, Norway, NBS are being considered as part of a potential reopening of the Kjørbekk stream. A 4-km stretch of the stream is contained in an aging pipe infrastructure that is buried under two disused landfills. The pipe infrastructure does not have the physical capacity to cope with an increase in precipitation brought about by current climate change, and in certain areas, the pipe has started to leak. This means that surface water runoff that cannot be accommodated by the pipe, as well as water that leaks from the pipe, can become contaminated by the waste in the disused landfill. Furthermore, the water can be transported with the stream course to the final recipient, taking the contamination with it. Reopening the stream and providing new water pathways can alleviate these problems, but it must be carried out so that contamination is not allowed to spread. This case study reveals how certain NBS that focus on reducing the amount of water in contact with pollutants, reducing the amount of particle spreading, remediating contaminated water, and remediating contaminated soil could be implemented at the site and function as a catalyst for an incremental city development. Integr Environ Assess Manag 2022;18:99-107. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).


Assuntos
Poluentes Químicos da Água , Água , Monitoramento Ambiental , Rios , Instalações de Eliminação de Resíduos , Poluentes Químicos da Água/análise , Abastecimento de Água
3.
Integr Environ Assess Manag ; 18(1): 39-41, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34676667

RESUMO

Incorporating nature-based solutions (NBSs) into the built environment supports the ongoing sustainability challenge as emphasized in the United Nations' Sustainable Development Goals (SDGs) and has particular relevance for SDG Goal #11 (Sustainable cities and communities), which seeks greater efficiencies in urban planning and management practices that address aging infrastructure and ongoing air, water, and soil pollution. The short communications and research articles in this special series exemplify many of these aspects, highlighting the application of NBSs and showcasing the latest environmental research and policy solutions to support this. Nature-based solutions in the built environment aim to promote the understanding of the transdisciplinary nature of NBSs and enhance the global awareness of the value of NBSs by providing a diversity of solutions to illustrate the positive economic, social, and environmental benefits of NBSs in the built environment. Integr Environ Assess Manag 2022;18:39-41. © 2021 The Authors. Integrated Environmental Assessment and Management published by Wiley Periodicals LLC on behalf of Society of Environmental Toxicology & Chemistry (SETAC).


Assuntos
Ecotoxicologia , Poluição Ambiental , Ambiente Construído , Desenvolvimento Sustentável , Água
6.
Sci Total Environ ; 646: 336-346, 2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30056229

RESUMO

The analysis of undisturbed sediment cores is a powerful tool for understanding spatial and temporal impacts of anthropogenic emissions from the energy and transport sectors at a regional scale. The spatial and vertical distribution of polycyclic aromatic hydrocarbons (PAHs) and black carbon (BC) were determined in 12 cores of recent (up to 20cm long) sediments from the Gulf of Gdansk in Poland, and Oslofjord/Drammensfjord in Norway. The Σ12PAHs levels in individual sediment layers varied from 250 to 4500ng/g d.w. in the Gulf of Gdansk, and from 210 to 4580ng/g d.w. in the Norwegian fjords. Analysis of PAH ratios indicates that PAHs in both studied areas originated mainly from pyrogenic sources. The BC concentrations in sediments were up to 0.9% and were generally higher in the Gulf of Gdansk (mean - 0.39%) than in Oslofjord/Drammensfjord (mean - 0.19%). The deposition history of anthropogenic emissions over the last 100years was reconstructed based on the analysis of dated and well-laminated sediment cores from two stations from the Gulf of Gdansk and two stations from the Norwegian fjords. The evolution in energy structure was especially evident in the Oslofjord, where transition from fossil fuel combustion to hydropower after 1960 coincided with a sharp decrease in sedimentary PAHs. Despite significant changes in the economic development in Poland, temporal patterns in PAH concentrations/profiles in the Gulf of Gdansk were not as obvious. The historical PAH trends in the Gulf of Gdansk may be related to the overwhelming PAH inputs from domestic combustion of solid fuels (coal, wood) for heating purposes. The implementation of legislation and other activities addressed to restrict the use of solid fuels in residential heating should reduce PAH emissions.

7.
Chemosphere ; 216: 404-412, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30384310

RESUMO

Produced water (PW) represents the largest volume waste stream in oil and gas production operations from most offshore platforms. PW is difficult to monitor as releases are rapidly diluted and concentrations can reach trace levels. The use of passive samplers can over come this. Here polyethylene (PE) was calibrated for a diverse range of PW pollutants. Zebrafish were exposed to dilutions of PW and passive sampler extracts in order to investigate the relationship between freely dissolved chemical concentrations and acute toxic effects. The raw PW had an LC50 of 13% (percentage of PW in the standardized zebrafish medium). Observed non-viable deformations to embryos (at 5 hpf) included heart and yolk edema, head, spine and tail deformations. The dose-response relationship of lethal effects showed that if 0.0041 g of PE is exposed to this PW, then extracted, 50% of exposed D. rerio will suffer lethal effects. The sum of tested freely dissolved concentrations that led to 50% lethal effects (mortality and non-viable deformations) was 2.32 × 10-4 mg/L for PW and 7.92 × 10-2 mg/L for PE. This implies that exposure to raw PW was more toxic than exposure to PE extracts. This toxicity was attributed both to the presence of contaminants as well as PW salinity. Passive samplers are able to detect very low freely dissolved pollutant concentrations which is important for assessing the spatial dilution of PW releases. Bioassays provide complimentary information as they account for all toxic compounds including those that are not taken up by passive samplers.


Assuntos
Monitoramento Ambiental/métodos , Indústria de Petróleo e Gás/normas , Águas Residuárias/química , Poluentes Químicos da Água/química , Animais , Bioensaio , Poluentes Químicos da Água/análise
8.
Mar Pollut Bull ; 133: 328-335, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30041322

RESUMO

Hazardous substances entering the sea, and ultimately deposited in bottom sediments, pose a growing threat to marine ecosystems. The present study characterized two coastal areas exposed to significant anthropogenic impact - Gulf of Gdansk (Poland), and Oslofjord/Drammensfjord (Norway) - by conducting a multi-proxy investigation of recent sediments, and comparing the results in light of different available thresholds for selected contaminants. Sediment samples were analyzed for benzo(a)pyrene (B(a)P) and other polycyclic aromatic hydrocarbons (PAHs), nonylphenols (NPs), organotin compounds (OTs), toxic metals (Cd, Hg, Pb), as well as mutagenic, genotoxic and endocrine-disrupting activities (in CALUX bioassays). In general, a declining trend in the deposition of contaminants was observed. Sediments from both basins were not highly contaminated with PAHs, NPs and metals, while OT levels may still give rise to concern in the Norwegian fjords. The results suggest that the contamination of sediments depends also on water/sediment conditions in a given region.


Assuntos
Sedimentos Geológicos/análise , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Ecossistema , Ecotoxicologia/métodos , Disruptores Endócrinos/análise , Disruptores Endócrinos/toxicidade , Monitoramento Ambiental/métodos , Estuários , Metais/análise , Mutagênicos/análise , Mutagênicos/toxicidade , Noruega , Compostos Orgânicos de Estanho/análise , Fenóis/análise , Polônia , Hidrocarbonetos Policíclicos Aromáticos/análise
9.
Environ Sci Technol ; 52(6): 3574-3582, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29488382

RESUMO

This work presents the results of an international interlaboratory comparison on ex situ passive sampling in sediments. The main objectives were to map the state of the science in passively sampling sediments, identify sources of variability, provide recommendations and practical guidance for standardized passive sampling, and advance the use of passive sampling in regulatory decision making by increasing confidence in the use of the technique. The study was performed by a consortium of 11 laboratories and included experiments with 14 passive sampling formats on 3 sediments for 25 target chemicals (PAHs and PCBs). The resulting overall interlaboratory variability was large (a factor of ∼10), but standardization of methods halved this variability. The remaining variability was primarily due to factors not related to passive sampling itself, i.e., sediment heterogeneity and analytical chemistry. Excluding the latter source of variability, by performing all analyses in one laboratory, showed that passive sampling results can have a high precision and a very low intermethod variability (

Assuntos
Sedimentos Geológicos , Poluentes Químicos da Água , Monitoramento Ambiental , Compostos Orgânicos , Medição de Risco
10.
Chemosphere ; 184: 1362-1371, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28693101

RESUMO

Polar organic chemical integrative samplers (POCIS) have previously been used to monitor alkylphenol (AP) contamination in water and produced water. However, only the sorbent receiving phase of the POCIS (Oasis beads) is traditionally analyzed, thus limiting the use of POCIS for monitoring a range of APs with varying hydrophobicity. Here a "pharmaceutical" POCIS was calibrated in the laboratory using a static renewal setup for APs (from 2-ethylphenol to 4-n-nonylphenol) with varying hydrophobicity (log Kow between 2.47 and 5.76). The POCIS sampler was calibrated over its 28 day integrative regime and sampling rates (Rs) were determined. Uptake was shown to be a function of AP hydrophobicity where compounds with log Kow < 4 were preferentially accumulated in Oasis beads, and compounds with log Kow > 5 were preferentially accumulated in the PES membranes. A lag phase (over a 24 h period) before uptake in to the PES membranes occurred was evident. This work demonstrates that the analysis of both POCIS phases is vital in order to correctly determine environmentally relevant concentrations owing to the fact that for APs with log Kow ≤ 4 uptake, to the PES membranes and the Oasis beads, involves different processes compared to APs with log Kow ≥ 4. The extraction of both the POCIS matrices is thus recommended in order to assess the concentration of hydrophobic APs (log Kow ≥ 4), as well as hydrophilic APs, most effectively.


Assuntos
Monitoramento Ambiental/instrumentação , Fenóis/análise , Poluentes Químicos da Água/análise , Calibragem , Interações Hidrofóbicas e Hidrofílicas , Compostos Orgânicos/química , Água/química
11.
Water Res ; 121: 109-119, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28525783

RESUMO

The aim of this study was to develop a toolset that can be used by site managers to assess and monitor natural attenuation processes in sediments contaminated with legacy hydrophobic organic contaminants. The toolset is composed of sediment traps to measure quality and deposition rate of incoming sediment under different hydrodynamic conditions, sediment cores to show trends in sediment bed concentrations over time, and passive samplers attached to a porewater probe frame to assess the mobility of buried contaminants and possible contaminant flux from sediment. These three tools were used together for the first time to assess the mobility of dichlorodiphenyltrichloroethane (DDT) contaminants in sediment in Pallanza Bay, Lake Maggiore, Italy. Depositing sediment and sediment cores were consistent in showing that DDT-contaminated sediment is undergoing burial by cleaner sediment. Elevated DDT concentrations from historical contamination seemed to be effectively buried and immobilized by ongoing deposition by cleaner sediment, because the positive flux from the elevated DDT concentration in the sediment porewater should not advance towards the sediment surface. The monitoring toolset introduced in this study enabled us to more effectively assess ongoing natural attenuation processes and provide more risk relevant data than traditional methods used in monitored natural recovery projects, such as bulk sediment concentrations from sediment cores. Our field assessment results suggest that incoming sediment from the Toce River have reduced DDT concentrations in the sediment compared to historic levels, and will continue to do so in locations where higher DDT concentrations are found within the bioactive layer.


Assuntos
Sedimentos Geológicos , Poluentes Químicos da Água , Baías , Monitoramento Ambiental , Itália , Lagos
12.
Environ Toxicol Chem ; 36(9): 2552-2559, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28294397

RESUMO

The recovery of the confined aquatic disposal (CAD) facility located at Malmøykalven in Oslofjord, Norway, has been assessed using an array of field measurement techniques. These methods were used prior to the disposal of dredged sediments as well as during 3 annual postdisposal monitoring campaigns. Traditional sampling to assess chemical recovery indicates that an immediate reduction in total sediment concentrations and surface sediments can be characterized as having good quality. Deposition of new material indicates that the quality of depositing material at the CAD is stabile and representative of the natural background quality in the area. Continued deposition of this material will improve the long-term chemical recovery of the CAD. A positive biological recovery of the benthic community has been observed and is expected to continue along a typical benthic succession pattern. To supplement traditional sampling, passive samplers were deployed at the CAD. Results suggest that the flux and concentrations of polycyclic aromatic hydrocarbon 16 and polychlorinated biphenyl 7 released from the CAD will continue to decrease over time. The combined results from these multiple lines of evidence indicate that the CAD and capping layer function as predicted 3 yr after the construction was completed. There is not only an improvement in the efficacy of the CAD itself but also a general improvement of the area, compared with the situation prior to disposal. Environ Toxicol Chem 2017;36:2552-2559. © 2017 SETAC.


Assuntos
Monitoramento Ambiental/métodos , Recuperação e Remediação Ambiental , Estuários , Bifenilos Policlorados/análise , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Sedimentos Geológicos/química , Noruega
13.
Mar Pollut Bull ; 111(1-2): 33-40, 2016 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-27514439

RESUMO

Stringent and periodic iteration of regulations related to the monitoring of chemical releases from the offshore oil and gas industry requires the use of ever changing, rapidly developing and technologically advancing techniques. Passive samplers play an important role in water column monitoring of produced water (PW) discharge to seawater under Norwegian regulation, where they are used to; i) measure aqueous concentrations of pollutants, ii) quantify the exposure of caged organisms and investigate PW dispersal, and iii) validate dispersal models. This article summarises current Norwegian water column monitoring practice and identifies research and methodological gaps for the use of passive samplers in monitoring. The main gaps are; i) the range of passive samplers used should be extended, ii) differences observed in absolute concentrations accumulated by passive samplers and organisms should be understood, and iii) the link between PW discharge concentrations and observed acute and sub-lethal ecotoxicological end points in organisms should be investigated.


Assuntos
Ecotoxicologia/métodos , Monitoramento Ambiental/métodos , Indústria de Petróleo e Gás , Águas Residuárias , Animais , Aquicultura , Bivalves , Meio Ambiente , Monitoramento Ambiental/legislação & jurisprudência , Modelos Teóricos , Noruega , Água do Mar/química , Eliminação de Resíduos Líquidos/métodos , Águas Residuárias/análise , Águas Residuárias/química , Poluentes Químicos da Água/análise
14.
Integr Environ Assess Manag ; 12(4): 690-700, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27260480

RESUMO

An integrative approach across disciplines is needed for sustainable lagoon and estuary management as identified by integrated coastal zone management. The ARCH research project (Architecture and roadmap to manage multiple pressures on lagoons) has taken initial steps to overcome the boundaries between disciplines and focus on cross-disciplinary integration by addressing the driving forces, challenges, and problems at various case study sites. A model was developed as a boundary-spanning activity to produce joint knowledge and understanding. The backbone of the model is formed by the interaction between the natural and human systems, including economy and governance-based subsystems. The model was used to create state-of-the-lagoon reports for 10 case study sites (lagoons and estuarine coastal areas), with a geographical distribution covering all major seas surrounding Europe. The reports functioned as boundary objects to build joint knowledge. The experiences related to the framing of the model and its subsequent implementation at the case study sites have resulted in key recommendations on how to address the challenges of cross-disciplinary work required for the proper management of complex social-ecological systems such as lagoons, estuarine areas, and other land-sea regions. Cross-disciplinary integration is initially resource intensive and time consuming; one should set aside the required resources and invest efforts at the forefront. It is crucial to create engagement among the group of researchers by focusing on a joint, appealing overall concept that will stimulate cross-sectoral thinking and focusing on the identified problems as a link between collected evidence and future management needs. Different methods for collecting evidence should be applied including both quantitative (jointly agreed indicators) and qualitative (narratives) information. Cross-disciplinary integration is facilitated by functional boundary objects. Integration offers important rewards in terms of developing a better understanding and subsequently improved management of complex social-ecological systems. Integr Environ Assess Manag 2016;12:690-700. © 2016 SETAC.


Assuntos
Ecossistema , Monitoramento Ambiental/métodos , Oceanos e Mares , Conservação dos Recursos Naturais/métodos , Europa (Continente)
15.
Integr Environ Assess Manag ; 12(4): 726-34, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27064511

RESUMO

This article shares the experiences, observations, and discussions that occurred during the completing of an ecosystem services (ES) indicator framework to be used at European Union (EU) and Member States' level. The experience base was drawn from 3 European research projects and 14 associated case study sites that include 13 transitional-water bodies (specifically 8 coastal lagoons, 4 riverine estuaries, and 1 fjord) and 1 coastal-water ecosystem. The ES pertinent to each case study site were identified along with indicators of these ES and data sources that could be used for mapping. During the process, several questions and uncertainties arose, followed by discussion, leading to these main lessons learned: 1) ES identification: Some ES that do not seem important at the European scale emerge as relevant at regional or local scales; 2) ES indicators: When direct indicators are not available, proxies for indicators (indirect indicators) might be used, including combined data on monitoring requirements imposed by EU legislation and international agreements; 3) ES mapping: Boundaries and appropriate data spatial resolution must be established because ES can be mapped at different temporal and spatial scales. We also acknowledge that mapping and assessment of ES supports the dialogue between human well-being and ecological status. From an evidence-based marine planning-process point of view, mapping and assessment of marine ES are of paramount importance to sustainable use of marine natural capital and to halt the loss of marine biodiversity. Integr Environ Assess Manag 2016;12:726-734. © 2016 SETAC.


Assuntos
Conservação dos Recursos Naturais/métodos , Ecossistema , Monitoramento Ambiental/métodos , Estuários , Biodiversidade , Política Ambiental , União Europeia
16.
Integr Environ Assess Manag ; 12(4): 701-10, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27064597

RESUMO

The European Union (EU) has taken the lead to promote the management of coastal systems. Management strategies are implemented by the Water Framework Directive (WFD) and the Marine Strategy Framework Directive (MSFD), as well as the recent Maritime Spatial Planning (MSP) Directive. Most EU directives have a strong focus on public participation; however, a recent review found that the actual involvement of stakeholders was variable. The "Architecture and roadmap to manage multiple pressures on lagoons" (ARCH) research project has developed and implemented participative methodologies at different case study sites throughout Europe. These cases represent a broad range of coastal systems, and they highlight different legislative frameworks that are relevant for coastal zone management. Stakeholder participation processes were subsequently evaluated at 3 case study sites in order to assess the actual implementation of participation in the context of their respective legislative frameworks: 1) Byfjorden in Bergen, Norway, in the context of the WFD; 2) Amvrakikos Gulf, Greece, in the context of the MSFD; and 3) Nordre Älv Estuary, Sweden, in the context of the MSP Directive. An overall assessment of the evaluation criteria indicates that the ARCH workshop series methodology of focusing first on the current status of the lagoon or estuary, then on future challenges, and finally on identifying management solutions provided a platform that was conducive for stakeholder participation. Results suggest that key criteria for a good participatory process were present and above average at the 3 case study sites. The results also indicate that the active engagement that was initiated at the 3 case study sites has led to capacity building among the participants, which is an important intermediary outcome of public participation. A strong connection between participatory processes and policy can ensure the legacy of the intermediary outcomes, which is an important and necessary start toward more permanent resource management outcomes such as ecological and economic improvement. Integr Environ Assess Manag 2016;12:701-710. © 2016 SETAC.


Assuntos
Conservação dos Recursos Naturais/métodos , Poluição da Água/estatística & dados numéricos , Ecossistema , Monitoramento Ambiental/métodos , Política Ambiental , União Europeia
17.
Integr Environ Assess Manag ; 10(2): 167-78, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24307344

RESUMO

This manuscript surveys the literature on passive sampler methods (PSMs) used in contaminated sediments to assess the chemical activity of organic contaminants. The chemical activity in turn dictates the reactivity and bioavailability of contaminants in sediment. Approaches to measure specific binding of compounds to sediment components, for example, amorphous carbon or specific types of reduced carbon, and the associated partition coefficients are difficult to determine, particularly for native sediment. Thus, the development of PSMs that represent the chemical activity of complex compound-sediment interactions, expressed as the freely dissolved contaminant concentration in porewater (Cfree ), offer a better proxy for endpoints of concern, such as reactivity, bioaccumulation, and toxicity. Passive sampling methods have estimated Cfree using both kinetic and equilibrium operating modes and used various polymers as the sorbing phase, for example, polydimethylsiloxane, polyethylene, and polyoxymethylene in various configurations, such as sheets, coated fibers, or vials containing thin films. These PSMs have been applied in laboratory exposures and field deployments covering a variety of spatial and temporal scales. A wide range of calibration conditions exist in the literature to estimate Cfree , but consensus values have not been established. The most critical criteria are the partition coefficient between water and the polymer phase and the equilibrium status of the sampler. In addition, the PSM must not appreciably deplete Cfree in the porewater. Some of the future challenges include establishing a standard approach for PSM measurements, correcting for nonequilibrium conditions, establishing guidance for selection and implementation of PSMs, and translating and applying data collected by PSMs.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Compostos Orgânicos/análise , Poluentes Químicos da Água/análise , Compostos Orgânicos/metabolismo , Poluentes Químicos da Água/metabolismo
18.
Environ Sci Technol ; 46(21): 12030-7, 2012 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-23046183

RESUMO

A large-scale field experiment on in situ thin-layer capping was carried out in the polychlorinated dibenzodioxin and dibenzofuran (PCDD/F) contaminated Grenlandsfjords, Norway. The main focus of the trial was to test the effectiveness of active caps (targeted thickness of 2.5 cm) consisting of powdered activated carbon (AC) mixed into locally dredged clean clay. Nonactive caps (targed thickness of 5 cm) consisting of clay without AC as well as crushed limestone were also tested. Fields with areas of 10,000 to 40,000 m(2) were established at 30 to 100 m water depth. Auxiliary shaken laboratory batch experiments showed that 2% of the applied powdered AC substantially reduced PCDD/F porewater concentrations, by >90% for tetra-, penta- and hexa-clorinated congeners to 60-70% for octachlorinated ones. In-situ AC profiles revealed that the AC was mixed into the sediment to 3 to 5 cm depth in 20 months. Only around 25% of the AC was found inside the pilot fields. Sediment-to-water PCDD/F fluxes measured by in situ diffusion chambers were significantly lower at the capped fields than at reference fields in the same fjord, reductions being largest for the limestone (50-90%) followed by clay (50-70%), and the AC + clay (60%). Also reductions in overlying aqueous PCDD/F concentrations measured by passive samplers were significant in most cases (20-40% reduction), probably because of the large size of the trial fields. The AC was less effective in the field than in the laboratory, probably due to prolonged sediment-to-AC mass transfer times for PCDD/Fs and field factors such as integrity of the cap, new deposition of contaminated sediment particles, and bioturbation. The present field data indicate that slightly thicker layers of limestone and dredged clay can show as good physicochemical effectiveness as thin caps of AC mixed with clay, at least for PCDD/Fs during the first two years after cap placement.


Assuntos
Benzofuranos , Recuperação e Remediação Ambiental/métodos , Sedimentos Geológicos , Dibenzodioxinas Policloradas/análogos & derivados , Poluentes Químicos da Água , Silicatos de Alumínio , Carbonato de Cálcio , Carbono , Argila , Dibenzofuranos Policlorados , Estuários , Noruega , Projetos Piloto , Água do Mar
19.
Environ Sci Technol ; 46(2): 810-7, 2012 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-22128748

RESUMO

Activated carbon (AC) amendment to polluted sediment or soil is an emerging in situ treatment technique that reduces freely dissolved porewater concentrations and subsequently reduces the ecological and human health risk of hydrophobic organic compounds (HOCs). An important question is the capacity of the amended AC after prolonged exposure in the field. To address this issue, sorption of freshly spiked and native HOCs to AC aged under natural field conditions and fresh AC amendments was compared for one soil and two sediments. After 12-32 months of field aging, all AC amendments demonstrated effectiveness for reducing pore water concentrations of both native (30-95%) and spiked (10-90%) HOCs compared to unamended sediment or soil. Values of K(AC) for field-aged AC were lower than freshly added AC for spiked HOCs up to a factor of 10, while the effect was less for native HOCs. The different behavior in sorbing native HOCs compared to freshly spiked HOCs was attributed to differences in the sorption kinetics and degree of competition for sorption sites between the contaminants and pore-clogging natural organic matter. The implications of these findings are that amended AC can still be effective in sorbing additional HOCs some years following amendment in the field. Thus, a certain level of long-term sustainability of this remediation approach is observed, but conclusions for decade-long periods cannot be drawn solely based on the present study.


Assuntos
Carbono/química , Sedimentos Geológicos/química , Compostos Orgânicos/química , Poluentes do Solo/química , Solo/química , Poluentes Químicos da Água/química , Adsorção , Monitoramento Ambiental , Rios/química
20.
Environ Sci Technol ; 45(14): 6110-6, 2011 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-21671651

RESUMO

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 a new 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.


Assuntos
Biodiversidade , Carvão Vegetal/química , Poluentes Ambientais/análise , Recuperação e Remediação Ambiental/métodos , Sedimentos Geológicos/análise , Invertebrados , Hidrocarbonetos Policíclicos Aromáticos/análise , Adsorção , Análise de Variância , Animais , Noruega , Gravação em Vídeo
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