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1.
Purpose
Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous and persistent contaminants in aquatic bed sediments. A better understanding of their in-bed fate and transport is therefore key in minimising the risk to the environment over time through various remediation and monitoring strategies. Since ecological effects and risks are related to contaminant concentrations, this study developed CoReTranS, a predictive model that simulates one-dimensional organic contaminant reaction and transport in bed sediments.Materials and methods
CoReTranS was benchmarked against analytical solutions of simplified reactive transport models and validated using a published study of marsh sediments contaminated with petroleum-derived hydrocarbons from Wild Harbour, West Falmouth, MA, USA.Results and discussion
The CoReTranS model effectively predicted the vertical distribution of PAHs in the Wild Harbour sediments as confirmed by the modelling results from the published study. The CoReTranS model was also used to interpret results from a published study of PAH-contaminated fjord sediments from Kitimat Arm in British Columbia, Canada. Specific insights into the post-depositional fate and transport of selected PAHs in the Kitimat fjord sediments were obtained by comparing the measured concentration-depth profiles with the numerical results from the CoReTranS model. Key parameters such as effective diffusivity of contaminants and burial velocities of sediment particles were shown to possibly account for the predicted concentrations-depth profiles in the Kitimat fjord sediments.Conclusions
As demonstrated, CoReTranS can simulate reactive transport models in order to predict PAH concentration profiles in porewater under site-specific conditions. The information derived from the use of the CoReTranS model highlighted practical application of such information by engineers to site-specific risk assessment and remediation. 相似文献2.
Matt Graham Erin Hartman Cheng He Ian G. Droppo 《Journal of Soils and Sediments》2013,13(8):1515-1526
Purpose
A sediment remediation project in Hamilton Harbour, Lake Ontario, Canada, proposes to use a thin layer cap for managing residual contamination from dredging as well as areas of marginal contamination not included in the dredge plan. Bottom shear stress (BSS) from weather, as well as propeller wash, have the potential to severely erode thin layer caps. The proposed thin layer cap was examined with respect to the BSS expected in Hamilton Harbour over a 6-month period.Materials and methods
BSS from vessels was estimated using published equations and BSS from weather using the MIKE 3 model. Critical shear stress for the capping sand was estimated using established equations and an annular flume.Results and discussion
Estimated BSS from marine vessels was found to exceed the critical shear stress in most cases. However, the extent of impact was difficult to determine and was mitigated to some extent by short vessel passage times, slightly differing routes and further sediment movement caused by weather. The average estimated BSS from weather for the study period was found to be below the critical shear stress for the capping sand, but the maximum BSS exceeded for a small area of the site.Conclusions
Apart from the shipping routes, the majority of the capping area should remain well below the critical shear stress. However, consideration of a larger grain size of capping material for the shallow areas should be considered. This would be of value for future storm conditions which might exceed what was experienced during the 6-month study period. 相似文献3.
Using in situ solid phase microextraction (SPME) for depth profiling in sediments treated with activated carbon 总被引：1，自引：1，他引：0
Ryan D. Stringer Joel G. Burken Andrew Curtis Elmore Danny D. Reible 《Journal of Soils and Sediments》2014,14(5):1013-1020
Purpose
Sediment contamination in US waterways is an expensive and complicated issue, and as acceptance of nontraditional sediment remediation strategies broadens, novel and efficient methods to assess and monitor the bioavailability of hydrophobic organic contaminants (HOCs) in contaminated sediments will play an important role.Materials and methods
In this project, solid phase microextraction (SPME) fibers inside perforated steel tubes were used as in situ passive samplers to measure polycyclic aromatic hydrocarbon (PAH) concentrations in sediment before and after treatment with activated carbon (AC). Two modes of waterjet amendment injection were used to apply the AC. In the first treatment, a single 2-min injection was shot into the center of a test vessel, and in the second treatment, multiple 7-s injections in a grid were placed in sediment.Results and discussion
In the single injection, no treatment was observed 5 cm away from the injection, while at 2.5 cm, >90 % decrease of PAH pore water concentration was observed, indicating a similar bioavailability decrease. In the multiple injection experiment, >90 % PAH pore water level reductions were observed throughout the test vessel. Highly contaminated and less contaminated sediments were mixed with 0–5 % AC by weight to develop AC treatment curves. Over 99 % reduction in PAH pore water concentrations and bioavailability was observed in the less contaminated sediment at 3 % AC, while 99 % reduction was never reached even at 5 % AC addition in the highly contaminated sediment. Different treatment curves were observed for the different contaminated sediments. In situ equilibration times were 120, 215, and 250 h for phenanthrene, pyrene, and benzo(a)anthracene, respectively.Conclusions
The results show that in situ SPME is a viable method to observe AC treatment and evaluate reductions in pore water concentrations and bioavailability. 相似文献4.
Dejan Krcmar Milena Dalmacija Bozo Dalmacija Miljana Prica Jelena Trickovic Elvira Karlovic 《Journal of Soils and Sediments》2013,13(7):1318-1326
Purpose
The objective of this research was to apply the same immobilization (stabilization/solidification) clay-based treatments to sediment contaminated with different metals (Pb, Cd, Ni, Zn, Cu, Cr) with different distributions and availabilities in sediment. We also examined the possibility of using clay as an immobilization agent without the application of thermal treatment, in order to reduce the economic cost of this expensive remediation procedure.Materials and methods
Clay from a canal in Vojvodina, Republic of Serbia, was used as the immobilization agent in a stabilization/solidification treatment to remediate metal-contaminated sediment. Semi-dynamic and toxicity characteristic leaching tests were conducted to assess the effectiveness of the nonthermal and thermal immobilization treatments with clay, and the long-term leaching behavior of these metals was determined using the following parameters: cumulative percentage of metals leached; diffusion coefficients; leachability indices; and toxicity characteristic leaching test concentration.Results and discussion
Based on these parameters, both clay-based treatments were effective in immobilizing metals in the contaminated sediment. Results suggest that both heating temperature and clay proportion in the sediment–clay mixture impact the degree of metal immobilization.Conclusions
Clay-based products are potentially good immobilization materials for metal-contaminated sediments, with the distribution of metals in the original sediment not influencing the efficacy of the treatments. Even without the thermal treatment, the metals were effectively immobilized. The leaching of metals was largely inside the regulatory limits and the treated samples can be regarded as nonhazardous materials. This justifies the choice of not applying the more expensive thermal treatment during remediation, especially when treating sediments containing a mixture of pollutants. 相似文献5.
Gitte Lemming Søndergaard Philip John Binning Morten Bondgaard Poul Løgstrup Bjerg 《Journal of Soils and Sediments》2018,18(11):3334-3348
Purpose
In order to improve and support decision-making for the selection of remedial techniques for contaminated sites, a multi-criteria assessment (MCA) method has been developed. The MCA framework is structured in a decision process actively involving stakeholders, and compares the sustainability of remediation alternatives by integrating environmental, societal, and economic criteria in the assessment.Materials and methods
The MCA includes five main decision criteria: remedial effect, remediation cost, remediation time, environmental impacts, and societal impacts. The main criteria are divided into a number of sub-criteria. The environmental impacts consider secondary impacts to the environment caused by remedial activities and are assessed by life-cycle assessment (LCA). The societal impacts mainly consider local impacts and are assessed in a more qualitative manner on a scale from 1 to 5. The performance on each main criterion is normalized to a score between 0 and 1, with 1 being the worst score. An overall score is obtained by calculating a weighted sum with criteria weights determined by stakeholders. The MCA method was applied to assess remediation alternatives for the Groyne 42 site, one of the largest contaminated sites in Denmark.Results and discussion
The compared remediation alternatives for the site were: (1) excavation of the site followed by soil treatment; (2) in situ alkaline hydrolysis; (3) in situ thermal remediation; and (4) continued encapsulation of the site by sheet piling. Criteria weights were derived by a stakeholder panel. The stakeholders gave the highest weighting to the remedial effect of the methods and to the societal impacts. For the Groyne 42 case study, the excavation option obtained the lowest overall score in the MCA, and was therefore found to be the most sustainable option. This was especially due to the fact that this option obtained a high score in the main categories Effect and Social impacts, which were weighted highest by the stakeholders.Conclusions
The developed MCA method is structured with five main criteria. Effect and time are included in addition to the three pillars of sustainability (environment, society, and economy). The remedial effect of remediation is therefore assessed and weighted separately from the main criteria environment. This structure makes interpretation of criteria scores more transparent and emphasizes the importance of effect and time as decision parameters. This also facilitated an easier weighting procedure for the stakeholders in the case study, who expressed a wish to weigh the remedial effect independently from the secondary environmental impacts.6.
Steffen Keiter Sabrina Peddinghaus Ute Feiler Britta von der Goltz Christoph Hafner Nga Yu Ho Sepand Rastegar Jens C. Otte Richard Ottermanns Georg Reifferscheid Uwe Strähle Thomas Braunbeck Monika Hammers-Wirtz Henner Hollert 《Journal of Soils and Sediments》2010,10(4):714-717
Introduction
The European Water Framework Directive aims to achieve a good ecological and chemical status in surface water of European rivers by the year 2015. Since sediments and particulate matter act as secondary sources for pollutants, applied sediment toxicology is perceived to play a major role for obtaining new knowledge that can contribute to successful attainment of the goal. However, the existing bioassays for sediment toxicity analyses do not provide sufficient data concerning bioavailability of environmental pollutants. In this regard, there is an urgent need to combine sediment contact assays with gene expression analysis to investigate mechanism-specific sediment toxicity.Purpose
The aim of the novel joint research project is to develop a eukaryotic test system, which can be used to investigate the ecotoxicological effects of contaminated sediments on gene expression level (DNA-array and RT-PCR). Current ecotoxicological research customarily involves a battery of bioassays to cover different toxicological endpoints (e.g., teratogenicity, genotoxicity, mutagenicity, Ah-receptor-mediated toxicity, neurotoxicity). In contrast, methods that detect alterations in gene expression offer deeper insight by elucidating how chemical exposure and/or environmental challenge affect multiple metabolic pathways leading to these particular kinds of toxic response. Gene expression profiles reflect the way cells and organisms adapt or respond to a changing environment.Conclusion
The present project aspires to increase the fundamental molecular and physiological knowledge concerning the mode of action of environmental toxicants in zebrafish (Danio rerio). By working with partners from the academic and research institutions as well as from industry and waterway regulations, the success of this basic research-driven joint project in terms of development and implementation of novel sediment toxicity methods will be realized. 相似文献7.
Kenneth Macrae Silje Kile Merete Grung Ketil Hylland 《Journal of Soils and Sediments》2012,12(6):921-932
Purpose
The highest concentrations of environmental contaminants are generally found in marine sediments, and there is a need for knowledge concerning how and whether they affect sediment-dwelling organisms. This study aimed to assess sublethal effects in Arenicola marina exposed to two sediments from a contaminated fjord and two reference locations with different sediment characteristics.Materials and methods
Duplicate contaminated sediments were used to investigate the robustness of current protocols for sediment testing. The two reference sediments, with different grain sizes and total organic carbon, were collected from the outer Oslofjord and the two contaminated sediments from Frierfjord. Polychaetes were exposed in quadruplicate sediment microcosms and sampled after 1, 2, 4 and 8?weeks of exposure. Oxidative stress resistance (total oxyradical scavenging capacity, TOSC) and components comprising the energy budget (cellular energy allocation, CEA) were determined for individual polychaetes.Results and discussion
Arenicola maintained and increased body weights over the initial 4?weeks of exposure in all groups, except in one reference sediment (Elle). There were no differences between treatments in the scavenging capacity (TOSC). The most striking difference in how polychaetes partitioned energy resources was a difference in lipid and carbohydrate allocations for Arenicola held in the contaminated sediments over the initial weeks. Cellular respiration appeared to increase in polychaetes held in the Elle sediment and decreased for polychaetes held in the two Frierfjord sediments by weeks?4 and 8. In the overall CEA, this was offset by increased energy per weight stored in the Elle group, which resulted in an overall positive CEA for polychaetes held in that sediment, whereas polychaetes in the other treatments were close to neutral. Although CEA would thus indicate that Elle polychaetes had good health status, their body weight also decreased significantly over the experimental period compared to other treatments, indicating an overall negative effect.Conclusions
This study has shown the importance of sediment characteristics when evaluating toxicity and how resource allocation can differ dramatically over a short time span in polychaetes held in similarly contaminated sediments. There were no clear effects of sediment contamination on CEA or TOSC in the polychaete A. marina. The findings are relevant for the design of both short- and long-term sediment studies. 相似文献8.
Goal, Scope and Background
The management of sediments poses complex problems. One of the problems is the division of decision-making power, knowledge and money across different actors. These interdependencies call for stakeholder involvement. The various risks of stakeholder involvement are discussed from practical experience. Following this discussion, recommendations will be made regarding the interactive management of sediments in national and cross-national rivers.Main Features
The first two sections will show stakeholder involvement to be both required and necessary. Stakeholder involvement ranges from no involvement, e.g. just being informed, to the other side of the scale where decision-making power is handed over to the stakeholders. Each level of participation has its own rules and roles for stakeholders, experts and policymakers. Once a certain level is chosen, the participants should adhere to it. The third section focuses on the risks accompanying stakeholder involvement. Two kinds of pitfalls are presented and discussed. The first covers general pitfalls that may occur in all kinds of processes. They comprise a lack of representativeness among the participants, the different levels of knowledge between experts and laymen, lack of communication between parties, clashing expectations when parties expect a different process than others, and finally the problem of neglecting the stakeholders when the policy process arrives at the decisionmaking phase. The second kind of pitfall occurs in international rivers. Matters become even more complicated when rivers cross borders. In that case, stakeholder involvement means dealing with different cultures and institutional differences as well.Results and Discussions
All these pitfalls mean that the process of stakeholder involvement is not as straightforward as it may seem. Every pitfall noted is accompanied by recommendations for the participants in future interactive processes of sedimentrelated policy-making.Conclusions
Involvement of stakeholders when dealing with sediments is complicated. The pitfalls mentioned call for a deliberate approach and set-up of such a process. Since European policymakers tend towards a higher appreciation of stakeholder involvement, it would be advisable to pay attention to those differences. Recommendations and Outlook. Apart from the recommendations given in this article, it is recommendable to carry out more empirical research into policy-processes regarding the management of sediments. To date, much research in this field has been of a theoretical nature, so that more empirical data is required.9.
Sansfica M. Young Hiroaki Ishiga Barry P. Roser Amarasooriya Pitawala 《Journal of Soils and Sediments》2014,14(1):204-217
Purpose
The geochemical compositions of sediments from three sectors in Trincomalee Bay (Koddiyar Bay, Thambalagam Bay and the Inner Harbour) in Sri Lanka were examined to determine fluvial and marine contributions and the effects of sorting and heavy mineral concentration. The present environmental status of the bay was also assessed.Materials and methods
Forty-nine sediment samples were collected from Trincomalee Bay and analysed by X-ray fluorescence, yielding data for the major elements and 17 trace elements. Mean grain size and sorting were also measured. Data were compared with the compositions of sediments from the lower Mahaweli River, which supplies most of the clastic detritus to Trincomalee Bay.Results and discussion
Sediments in the three sectors differ significantly in chemical composition, according to position relative to the Mahaweli River delta source, depositional environment, heavy mineral concentration and marine influences. According to accepted sediment quality guidelines, some As contamination may have occurred in the Inner Harbour and Thambalagam Bay and Cr contamination in all three sectors.Conclusions
Proximal Koddiyar Bay sediments compare closely with Mahaweli River bedload. Although the clastic component in the more distal Thambalagam Bay and the Inner Harbour is also derived from the Mahaweli River, compositions are modified significantly by marine contributions. High concentrations of elements including Ti, Zr, Ce, Nb and Y in NW Koddiyar Bay are consistent with heavy mineral concentration by winnowing in high-energy zones. Some decoupling of Fe–Ti- and Zr-bearing heavy mineral assemblages may occur within the bay. Al-normalized metal enrichment factors and contour maps show that apparent contamination by As and Cr is spurious and is caused by locally high background levels from Mahaweli River detritus. This illustrates the importance of establishing local background levels of elements during environmental studies. 相似文献10.
Farhan Hafeez Laurent Philippot Aymé Spor Fabrice Martin-Laurent 《Journal of Soils and Sediments》2014,14(1):178-182
Purpose
Soil contamination by pollutants is increasing, urging for remediation strategies but little is known about the functional sustainability of these strategies.Materials and methods
We assessed the resistance and resistance of a microbial respiratory process, denitrification, to two different levels of heat-drought disturbances among (1) thermally treated industrial soil, (2) constructed Technosol made of thermally treated soil, compost, and paper by products, and (3) an arable soil.Results and discussion
We showed that thermal remediation lead to low resistance and resilience after disturbances. However, addition of compost and paper mill sludge improved the stability.Conclusions
This work underlines the relevance of resistance and resilience ecological concepts for assessing remediation strategies. 相似文献11.
Potential contaminant release from agricultural soil and dredged sediment following managed realignment 总被引：1，自引：1，他引：0
Margaret Kadiri Kate L. Spencer Catherine M. Heppell 《Journal of Soils and Sediments》2012,12(10):1581-1592
Purpose
Laboratory experiments were conducted to examine the potential for metal (Cu, Ni and Zn) and herbicide (simazine, atrazine and diuron) release from agricultural soil and dredged sediment in managed realignment sites following tidal inundation.Materials and methods
Column microcosm and batch sorption experiments were carried out at low (5?practical salinity units, psu) and high (20?psu) salinity to evaluate the changes in the partitioning of metals and herbicides between the soil/sediment and the aqueous phase, and the release of metals and herbicides from soil/sediment to the overlying water column.Results and discussion
For both the metals and herbicides, the highest contaminant loads were released from the sediment within the first 24?h of inundation suggesting that any negative impacts to overlying water quality in a managed realignment scheme will be relatively short term following tidal inundation of soil and sediment. The release of metals was found to be dependent on a combination of salinity effects and the strength of binding of the metals to the soil and sediment. In the case of the herbicides, salinity impacted on their release. Particulate organic carbon was found to control the binding and release of the herbicides, highlighting the importance of assessing soil and sediment organic matter content when planning managed realignment sites.Conclusions
Our research demonstrates that metals and herbicides may be released from contaminated sediments and agricultural soils during initial periods of flooding by seawater in managed realignment sites. 相似文献12.
Anne Mercier Guillaume Wille Caroline Michel Jennifer Harris-Hellal Laurence Amalric Catherine Morlay Fabienne Battaglia-Brunet 《Journal of Soils and Sediments》2013,13(4):793-800
Purpose
Granular activated carbon (GAC) that is both an efficient polychlorinated biphenyl (PCB) adsorbent and a good growth support for microorganisms is considered suitable for in situ remediation of PCB-contaminated aquatic sediment. Here, the potential competition between biofilm formation and PCB (Aroclor 1260) adsorption on GAC in a PCB-contaminated aquatic sediment was investigated.Materials and methods
GACs, both coated and uncoated with biofilm or PCBs, were incubated with sediment. Each was monitored for biofilm development and PCB adsorption by: (a) cryo-scanning electron microscopy, (b) real-time quantitative PCR analysis of the 16S rRNA, (c) terminal restriction fragment length polymorphism and (d) chemical analysis.Results and discussion
Biofilm formation on the GAC by the sediment's bacteria was rapid and occurred in three stages: (1) initial adherence of discrete bacteria, (2) an increase in biomass associated with a shift in bacterial diversity and (3) exopolymeric matrix production. The density and biodiversity of the multispecies biofilm depended on the biofilm's age. The addition of Aroclor 1260 to the sediment resulted in a decrease of the biofilm biomass, whereas Aroclor 1260 previously adsorbed on the GAC prior to contact with the sediment did not influence the biofilm biomass or its formation dynamics. Similarly, a biofilm previously developed on the GAC did not significantly decrease PCB adsorption, although contact of the GAC with the sediment did hamper adsorption of the higher chlorinated PCB congeners.Conclusions
A mature multispecies bacterial biofilm developed in 1 month on GAC in contact with aquatic sediment did not hamper PCB adsorption, and PCB adsorption did not influence biofilm formation. These findings are important for the application of remediation strategies. 相似文献13.
Maha Chalhoub Laurence Amalric Solène Touzé Pierre Gallé Pascal E. Reiller Noëlle Doucet Blandine Clozel Philippe Bataillard 《Journal of Soils and Sediments》2013,13(7):1284-1300
Purpose
Remobilization of polychlorobiphenyl (PCB)-contaminated sediments by anthropogenic activities (e.g. dredging) or natural flow conditions could lead to the release of PCBs into the water column and consequently increase the availability of PCBs to benthic organisms. The fate of the released PCBs following such events is not well understood and such knowledge is necessary for the management of contaminated sediments. The objective of this study was to understand the processes that control the fate of PCBs following remobilization of field-aged contaminated sediments.Materials and methods
Sediments contaminated with PCBs collected from Lake Bourget (Savoie, France) were resuspended in a column experiment. The relationships between physical–chemical parameters—i.e. suspended particulate matter, pH, inorganic and organic carbon content, redox-sensitive species and the concentrations of dissolved PCBs both in the water column and in the interstitial water of the sediment—were investigated so as to determine the key processes controlling PCB fate.Results and discussion
Following the simulated resuspension event (SRE), dissolved PCBs were found in much higher concentrations in the water column than under stationary conditions. Desorption of PCBs from the sediment depended on the degree of the hydrophobicity of the PCBs and the initial PCB content in the sediment. Principal component analysis showed that the variations in the concentrations of released PCBs over time and space closely followed those of suspended particulate matter (SPM) and not those of redox conditions. The partitioning behaviour of PCBs on SPM showed that equilibrium state was not attained within 40 days following the SRE. A particle size fractionation study, before and after remobilization of the sediment, showed the presence of PCBs in every fraction of the sediment, but with higher amounts in large particles with high organic matter content and in the finest fractions. Remobilization of contaminated sediment did not affect this distribution profoundly but a significant enrichment in PCBs of the clay-sized fraction was observed in the re-settled sediment.Conclusions
Sediment resuspension induced non-equilibrium conditions in the water column for more than 5 weeks and led to the enrichment with PCBs of the newly formed surface bed sediment. This enrichment was due to the preferential re-sorption of PCBs on clay-sized particles during the SRE and to the physical segregation and accumulation of the less dense particles at the surface of the sediment column; such particles thought to be the principal carriers of contaminants. These changes concerned <0.05 % of the total PCB content. 相似文献14.
Enhanced bioremediation of PAH-contaminated soil by immobilized bacteria with plant residue and biochar as carriers 总被引：2，自引：0，他引：2
Purpose
Polycyclic aromatic hydrocarbons (PAHs) are largely accumulated in soils in China. The immobilized-microorganism technique (IMT) is a potential approach for abating soil contamination with PAHs. However, few studies about the application of IMT to contaminated soil remediation were reported. Due to recalcitrance to decomposition, biochar application to soil may enhance soil carbon sequestration, but few studies on the application of biochars to remediation of contaminated soil were reported. In this study, we illustrated enhanced bioremediation of soil having a long history of PAH contamination by IMT using plant residues and biochars as carriers.Materials and methods
Two PAH-degrading bacteria, Pseudomonas putida and an unidentified indigenous bacterium, were selected for IMT. The extractability and biodegradation of 15 PAHs in solution and an actual PAH-contaminated soil amended with immobilized-bacteria materials were investigated under different incubation periods. The effects of carriers and the molecular weight of PAHs on bioremediation efficiency were determined to illustrate their different bio-dissipation mechanisms of PAHs in soil.Results and discussion
The IMT can considerably enhance the removal of PAHs. Carriers impose different effects on PAH bio-dissipation by amended soil with immobilized-bacteria, which can directly degrade the carrier-associated PAHs. The removal of PAHs from soil depended on PAH molecular weight and carrier types. Enhanced bio-dissipation by IMT was much stronger for 4- and 5-ring PAHs than for 3- and 6-ring ones in soil. Only P400 biochar-immobilized bacteria enhanced bio-dissipation of all PAHs in contaminated soil after a 90-day incubation.Conclusions
Biochar can promote bioremediation of contaminated soil as microbial carriers of IMT. It is vital to select an appropriate biochar as an immobilized carrier to stimulate biodegradation. It is feasible to use adsorption carriers with high sorptive capabilities to concentrate PAHs as well as microorganisms and thereby enhance dissipation of PAHs and mitigate soil pollution. 相似文献15.
Burton C. Suedel Charles H. Lutz Joan U. Clarke Douglas G. Clarke 《Journal of Soils and Sediments》2012,12(6):995-1003
Purpose
Sediment resuspension is among the most widely cited concerns that lead to restricted dredging timeframes. Protection of fish species is a primary concern regarding the effects of dredging operations, yet experimental data establishing thresholds for uncontaminated suspended sediment effects are largely lacking. We conducted research to determine suspended sediment effects on walleye (Sander vitreus) egg hatching success and gross morphology following exposures mimicking sediment resuspension during dredging operations.Materials and methods
Newly spawned eggs of northern and southern walleye strains were continuously exposed for 3?days to suspended sediment concentrations of 0, 100, 250, and 500?mg?l?1, using sediment from Maumee Bay, OH, USA. These concentrations spanned the range measured in the vicinity of dredging operations in the Western Basin of Lake Erie.Results and discussion
Northern and southern strain egg hatching rates were 53% and 39% of exposed eggs and 82% and 74% of viable eggs exposed, which are within reported ranges for this species. Data indicated no statistically significant effects of suspended sediment on hatching success. Gross morphological observations of exposed fry yielded no evidence of detrimental effects.Conclusions
Experimental results indicated that walleye eggs are relatively tolerant to exposures likely to be encountered at dredging projects as performed in the Great Lakes region. Our results suggest that, given detailed knowledge of dredging project site-specific conditions and the mode of dredging to be used, better informed decisions can be made regarding adequate protective management practices. In many cases, flexibility could be given to the dredging contractor while maintaining a very low probability of risk to walleye spawning habitat. 相似文献16.
Gerd Wessolek Björn Kluge Steffen Trinks Michael Facklam Olaf Zeuschner 《Journal of Soils and Sediments》2018,18(2):481-493
Purpose
Wastewater irrigation is still a common practice in many cities worldwide. After ending the wastewater irrigation, the question arises as to how the highly polluted areas can be reused. Mostly, the remediation costs for liming or adding synthetic soil conditioners are too high for decision makers, often leading to unattractive wastelands in neighboring suburbs. This story shows how part of a former wastewater disposal field in Berlin (Germany) was remediated by adding and mixing loam-rich glacial until excavated from subway construction work. The remediation led to long-term improvements of soil and landscape, which nowadays is an attractive forested recreation area. Part of this landscape is used as an ecological lab for research, art, and education.Materials and methods
The article summarizes the results of soil analysis of the contamination status and remediation technique over the last 2 decades. We collected and reevaluated historical data, research results, technical reports, and graphic materials concerning the wastewater disposal field in Berlin, Germany.Results and discussion
The remediation concept without adding any synthetic substances was a successful soft technology leading to (i) a reduction of the long-term groundwater risk, (ii) an immobilization of the trace element concentration in the soil solution, and (iii) a reduction of the metal uptake by plants. Remediation led to much better conditions for plant growth, soil fauna, and microbiological activity, which improved the environment in a sustainable way. The implementation of a new landscape concept combining ecology, culture, and art totally changed the character of the landscape from former stinking wastewater fields to present-day attractive sites that can be used for many purposes.Conclusions
The remediation of the former wastewater disposal fields, using natural glacial till materials rich in clay and silt, became a “story of success.” However, a remediation project of this type and scope only becomes reality if all responsible actors in society participate continuously. We conclude that stakeholders should not focus only on remediation costs but also on the benefits for society: reclaiming waste sites significantly improves our well-being.17.
Susanne Siebeneicher Dierk-Steffen Wahrendorf Markus A. Wetzel Dirk Jungmann 《Journal of Soils and Sediments》2013,13(1):197-206
Purpose
Acute whole-sediment bioassay with the estuarine and marine amphipod Corophium volutator (Pallas) is widely used to assess toxicity of sediments. According to the guidelines DIN EN ISO 16712, mortality is the determined toxic endpoint. Additionally, the reburrowing ability of the surviving organisms of this acute toxicity test in fresh uncontaminated sediment is suggested as the sublethal endpoint, but insufficient information (e.g., exact measurement protocols) on this endpoint is provided, thus confounding factors and the interpretation of the results. The aim of this study was to provide information on burrowing activity as a sublethal endpoint.Materials and methods
Amphipod tests were carried out in the laboratory, and the burrowing behavior was examined in a size- and gender-specific manner. For sediment testing, only animals of the same size were used in a defined sex ratio because it was found that female animals buried themselves faster than males and that smaller animals burrowed faster than bigger organisms. Statistical analyses were applied to determine whether burrowing time and ability differ significantly between sexes and sizes. Finally, tests were run to discern whether the burrowing ability could be a more sensitive endpoint than mortality.Results and discussion
When the burrowing ability was examined in toxicity tests with contaminated sediment, the test organisms were affected in a dose-dependent manner. With rising concentrations of the contaminated sediment in a sublethal testing following the sediment exposure over 10 days, fewer animals buried themselves into the sediment.Conclusions
The burrowing behavior can be used as an additional endpoint. For the tested sediment, burrowing was found to be more sensitive than the mortality. Guidance on the measurement protocol for this additional endpoint was developed. Under the test conditions examined, burrowing ability is an appropriate sublethal endpoint to supplement the toxicity test procedure. 相似文献18.
Petra Scanferla Giorgio Ferrari Roberto Pellay Annamaria Volpi Ghirardini Gabriele Zanetto Giovanni Libralato 《Journal of Soils and Sediments》2009,9(3):229-236
Background, aim, and scope
An innovative stabilization/solidification (S/S) process using high-performance additivated concrete technology was developed for remediating soil contaminated by metals from abandoned industrial sites. In order to verify the effectiveness of this new ex situ S/S procedure, an area highly contaminated by metallic pollutants (As, Cd, Hg, and Pb), due to the uncontrolled discharge of waste generated from artistic glass production on the island of Murano (Venice, Italy), was selected as a case study. The technique transforms the contaminated soil into an aggregate material suitable for reuse as on-site backfill. This paper reports the main results of the demonstration project performed in collaboration with the local environmental protection agency (ARPAV).Materials and methods
An ex situ treatment for brownfield remediation, based on the transformation of contaminated soil into very dense, low porous, and mechanically resistant granular material, was set up and tested. Specific additives (water reducers and superplasticizers) to improve the stabilized material properties were developed and patented. A demonstration plant assembled on the study area to treat 6 m3 h–1was then tested. After excavation, the contaminated soil was screened to remove coarse material. The fraction Ø?>?4 mm (coarse fraction), mainly composed of glass, brick, concrete, and stone debris, was directly reused on site after passing through a washing treatment section. The highly polluted fraction Ø?≤?4 mm (fine fraction) was treated in the S/S treatment division of the plant (European patent WO/2006/097272). The fine fraction was mixed with Portland cement and additives defined on the basis of the high performance concrete technique. the mixture was then granulated in a rolling-plate system. After 28 days curing in an onsite storage area to allow for cement hydration, the stabilized material was monitored before its in situ relocation. The chemical, mechanical, and ecotoxicological reliability and performance of the treatment was checked. Metal leachability was verified according to four leaching test methods: Italian Environmental Ministry Decree (1998), EN 12457 (2002) tout court, amended only with MgSO4 and, lastly, with artificial sea water. The mechanical properties were measured according to BS (1990) and AASHTO (1999) to obtain the Aggregate Crushing Value and California Bearing Ratio, in that order. Moreover, leachate samples prepared with artificial seawater were assessed via the Crassostrea gigas embryotoxicity test and Vibrio fischeri bioluminescence inhibition test to discriminate the presence of potential ecotoxicological effects for the brackish and saltwater biota.Results
Outcomes from all leachate samples highlighted the effectiveness of the remediation treatment, fully complying with the Italian legislation for non-hazardous material reuse under a physicochemical viewpoint. The stabilized granular material demonstrated high mechanical strength, low porosity, and leachability. Moreover, ecotoxicological surveys indicated the presence of low toxicity levels in leachate samples according to both toxicity tests.Discussion
Remediated soil samples revealed a significant decrease in leachability of heavy metals as a consequence of the application of additivated cement that enhanced granular material properties, resulting in improved compactness due to the reduction in water content. The toxicity data confirmed this state-of-the-art technique, indicating that leachates could be deemed as minor acutely toxic.Conclusions
The proposed S/S treatment proved to be able to remediate soil contaminated by heavy metals through trapping pollutants in pellet materials presenting adequate physicochemical, mechanical, and ecotoxicological properties in order to prevent leachability phenomena, their reclamation, and reuse being made easier by its granular form.Recommendation and perspectives
This project foresees long-term monitoring activity over several years (until 2014) to consider treatment durability. 相似文献19.
Purpose
Enhancing desorption of hydrophobic organic contaminants from soils is a promising approach for the effective remediation of soils contaminated with organic compounds. The desorption efficiency of chemical reagent, such as surfactant, should be evaluated. In this study, the effect of mixed anionic–nonionic surfactants sodium dodecylbenzene sulfonate (SDBS)–Tween 80 on the distribution of polycyclic aromatic hydrocarbons in soil–water system was evaluated.Materials and methods
Batch desorption experiments were employed to evaluate the distribution of polycyclic aromatic hydrocarbons (PAHs) and surfactants in soil–water system. PAHs and SDBS were determined by high-performance liquid chromatography, Tween 80 by spectrophotometry, and total organic carbon with a carbon analyzer.Results and discussion
Sorption of PAHs to soil was increased at low surfactant concentration due to the effective partition phase on soil formed by sorbed surfactants. The mixture of anionic and nonionic surfactants decreased the sorption of surfactants to soil, increasing the effective surfactant concentration in solution and thus decreasing the sorption of PAHs on soil. Anionic–nonionic mixed surfactant showed better performance on desorption of PAHs from soil than single surfactant. The greatest desorption efficiency was achieved with low proportions of SDBS (SDBS/Tween80?=?1:9).Conclusions
SDBS–Tween 80 mixed surfactant showed the highest desorption rate with low proportion of SDBS, which indicated that the addition of relative low amount of anionic surfactant could significantly promote the desorption efficiency of PAHs by nonionic surfactants. Results obtained from this study did provide useful information in surfactant-enhanced remediation of soil and subsurface contaminated by hydrophobic organic compounds. 相似文献20.
Assessment of diffuse pollution associated with metals in urban sediments using the geoaccumulation index (Igeo) 总被引：1，自引：1，他引：0