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Purpose Stabilization and solidification (S/S) is a technique that enhances the structural properties of the sediment and reduces contaminant mobility, enabling the utilization of dredged contaminated sediment. Further reduction of the contaminants before S/S is, however, desirable to minimize leaching. The metal and organotin content in sediment could be reduced by electrochemical treatment. This is the first study on how electrochemical pretreatment impacts the strength and leaching properties of stabilized sediments. Methods Sediment was sampled from a port and was treated by using electrolysis. The removal of metals and organotin was investigated. Both treated and non-treated sediment was stabilized to investigate how electrolysis and also how different salinity and concentrations of organic matter during the curing affected the S/S properties by doing compression tests and leching tests. Results The electrolysis resulted in a 22% reduction of tributyltin (TBT) and a 44% reduction of zinc in the sediment. The results showed that the electrolyzed stabilized samples passed the requirements for compression strength and had a reduced surface leaching of zinc. Curing in saline conditions was beneficial for strength development and reducing the leaching of TBT. Conclusion Electrolysis reduced the sediment’s TBT and metal content, and the results indicate that pretreatment before stabilization could be beneficial to reduce contaminant leaching and to recover metals from the sediment. This study highlights the importance of investigating if a specific stabilization recipe fulfills the strength and leaching criteria in water similar to the field condition to assure satisfying results once implemented in the field.

This study has developed and applied a framework to analyse barriers, opportunities, and potential solutions for the diffusion of alternative fuels, here exemplified by liquefied biogas (LBG) for heavy trucks. The study is based on expert and stakeholder interviews in Sweden. Also, the study estimates a cost example of using heavy duty LBG-trucks instead of conventional diesel trucks. The framework is based on two previously published frameworks to categorise barriers, opportunities, and potential solutions and comprises five categories: financial, technical/commercial/physical, policy, public acceptability, and market structure/interaction barriers. Each category considers both the system and actor levels. The results of this study fit the framework's categories well, and the framework is appropriate for analysing the diffusion of liquefied biogas for heavy trucks, and other technologies with similar characteristics. The results further indicate that a network level, in addition to the system and actor levels, could advance our understanding of renewable energy diffusion. The most mentioned opportunities were climate/environmental benefits, potential profitability, and newly introduced policies. The cost estimates show that given current taxes and policies in Sweden, the costs of using LBG-trucks are only marginally higher than those of using conventional diesel trucks. Commonly cited barriers were financial issues, an unstable policy context, lack of infrastructure, and lack of knowledge. Suggested solutions for overcoming barriers were financial incentives, a stable policy context, demonstration projects, and information campaigns. Improved knowledge and working together throughout the biogas value chain, with a palette of renewable energy options, are important for accelerating a sustainable renewable fuel diffusion. Several policy instruments that currently exists in Sweden already target the mentioned barriers. Thus, it is important to continuously evaluate policy instruments to understand if they are effective and efficient, or if anything need to be changed to reach the targets of the policy instrument. © 2021 The Authors

Tires, bitumen, and road markings are important sources of traffic-derived carbonaceous wear particles and microplastic (MP) pollution. In this study, we further developed a machine-learning algorithm coupled to an automated scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDX) analytical approach to classify and quantify the relative number of the following subclasses contained in environmental road dust: tire wear particles (TWP), bitumen wear particles (BiWP), road markings, reflecting glass beads, metallics, minerals, and biogenic/organics. The method is non-destructive, rapid, repeatable, and enables information about the size, shape, and elemental composition of particles 2–125 µm. The results showed that the method enabled differentiation between TWP and BiWP for particles > 20 µm with satisfying results. Furthermore, the relative number concentration of the subclasses was similar in both analyzed size fractions (2–20 µm and 20–125 µm), with minerals as the most dominant subclass (2–20 µm x̄ = 78%, 20–125 µm x̄ = 74%) followed by tire and bitumen wear particles, TBiWP, (2–20 µm x̄ = 19%, 20–125 µm x̄ = 22%). Road marking wear, glass beads, and metal wear contributed to x̄ = 1%, x̄ = 0.1%, and x̄ = 1% in the 2–20-µm fraction and to x̄ = 0.5%, x̄ = 0.2%, and x̄ = 0.4% in the 20–125-µm fraction. The present results show that road dust appreciably consists of TWP and BiWP within both the coarse and the fine size fraction. The study delivers quantitative evidence of the importance of tires, bitumen, road marking, and glass beads besides minerals and metals to wear particles and MP pollution in traffic environments based on environmental (real-world) samples

Severe accidents and high costs associated with weather-related events already occur in today’s climate. Unless preventive measures are taken, the costs are expected to increase in future due to ongoing climate change. However, the risk reduction measures are costly as well and may result in unwanted impacts. Therefore, it is important to identify, assess and prioritize which measures are necessary to undertake, as well as where and when these are to be undertaken. To be able to make such evaluations, robust (scientifically based), transparent and systematic assessments and valuations are required. This article describes a framework to assess the cause-and-effect relationships and how to estimate the costs and benefits as a basis to assess and prioritize measures for climate adaptation of roads and railways. The framework includes hazard identification, risk analysis and risk assessment, identification, monetary and non-monetary evaluation of possible risk reduction measures and a step regarding distribution-, goal- and sensitivity analyses. The results from applying the framework shall be used to prioritize among potential risk reduction measures as well as when to undertake them.

Large quantities of sediment must be dredged regularly to enable marine transport and trade. The sediments are often polluted, with e.g. metals, which limits the management options. The aim of this study has been to assess costs and environmental impacts (impact on climate, marine organisms, etc.) of different management options for polluted dredged sediment, by combining life-cycle assessment (LCA) of the climate impact, scoring of other environmental aspects and a cost evaluation. This approach has been used to study both traditional and new management alternatives for a real port case. The studied options include landfilling, deep-sea disposal, construction of a port area using a stabilization and solidification (S/S) method, and a combination of the aforementioned methods with the innovative option of metal recovery through sediment electrolysis. The LCA showed that deep-sea disposal had the lowest climate impact. The assessment of the other environmental impacts showed that the result varied depending on the pollution level and the time perspective used (short or long-term). Using sediment for construction had the highest climate impact, although other environmental impacts were comparably low. Electrolysis was found to be suitable for highly polluted sediments, as it left the sediment cleaner and enabled recovery of precious metals, however the costs were high. The results highlight the complexity of comparing different environmental impacts and the benefits of using integrated assessments to provide clarity, and to evaluate both the synergetic and counteracting effects associated with the investigated scenarios and may aid early-stage decision making. © 2021 The Authors

Metal and tributyltin (TBT) contaminated sediments are problematic for sediment managers and the environment. This study is the first to compare Fenton’s reagent and electrochemical treatment as remediation methods for the removal of TBT and metals using laboratory-scale experiments on contaminated dredged sediment. The costs and the applicability of the developed methods were also compared and discussed. Both methods removed > 98% TBT from TBT-spiked sediment samples, while Fenton’s reagent removed 64% of the TBT and electrolysis 58% of the TBT from non-spiked samples. TBT in water phase was effectively degraded in both experiments on spiked water and in leachates during the treatment of the sediment. Positive correlations were observed between TBT removal and the added amount of hydrogen peroxide and current density. Both methods removed metals from the sediment, but Fenton’s reagent was identified as the most potent option for effective removal of both metals and TBT, especially from highly metal-contaminated sediment. However, due to risks associated with the required chemicals and low pH level in the sediment residue following the Fenton treatment, electrochemical treatment could be a more sustainable option for treating larger quantities of contaminated sediment.

Gentle Remediation Options (GRO) are remediation measures involving plants, fungi, bacteria, and soil amendments that can be applied to manage risks at contaminated sites. Several studies and decision-support tools promote the wider range of benefits provided by GRO, but there is still skepticism regarding GRO implementation. Key issues that need to be better communicated are the various risk mitigation mechanisms, the required risk reduction for an envisioned land use, and the time perspective associated with the risk mitigation mechanisms. To increase the viability and acceptance of GRO, the phytomanagement approach implies the combination of GRO with beneficial green land use, gradually reducing risks and restoring ecosystem services. To strengthen the decision basis for GRO implementation in practice, this paper proposes a framework for risk management and communication of GRO applications to support phytomanagement strategies at contaminated sites. The mapping of the risk mitigation mechanisms is done by an extensive literature review and the Swedish national soil guideline value model is used to derive the most relevant human health exposure pathways and ecological risks for generic green land use scenarios. Results indicate that most of the expected risk mitigation mechanisms are supported by literature, but that knowledge gaps still exist. The framework is demonstrated to support the identification of GRO options for the case study site given two envisioned land uses: biofuel park and allotment garden. A more easily understandable risk management framework, as proposed here, is expected to act as a communication tool to educate decision-makers, regulatory bodies and other stakeholders for better understanding of risk mitigation mechanisms and preliminary timeframes of various GRO, particularly in the early stages of a brownfield redevelopment project. © 2021 The Authors

In urban environments, particularly areas under reconstruction, metals, organic pollutants (OP), and microplastics (MP), are released in large amounts due to heavy traffic. Road runoff, a major transport route for urban pollutants, contributes significantly to a deteriorated water quality in receiving waters. This study was conducted in Gothenburg, Sweden, and is unique because it simultaneously investigates the occurrence of OP, metals, and MP on roads and in stormwater from an urban area under reconstruction. Correlations between the various pollutants were also explored. The study was carried out by collecting washwater and sweepsand generated from street sweeping, road surface sampling, and flow-proportional stormwater sampling on several occasions. The liquid and solid samples were analyzed for metals, polycyclic aromatic hydrocarbons (PAH), oxy-PAH, aliphatics, aromatics, phthalates, and MP. The occurrence of OP was also analyzed with a non-target screening method of selected samples. Microplastics, i.e. plastic fragments/fibers, paint fragments, tire wear particles (TWP) and bitumen, were analyzed with a method based on density separation with sodium iodide and identification with a stereo microscope, melt-tests, and tactile identification. MP concentrations amounted to 1500 particles/L in stormwater, 51,000 particles/L in washwater, and 2.6 × 106 particles/kg dw in sweepsand. In stormwater, washwater and sweepsand, MP ≥20 μm were found to be dominated by TWP (38%, 83% and 78%, respectively). The results confirm traffic as an important source to MP, OP, and metal emissions. Concentrations exceeding water and sediment quality guidelines for metals (e.g. Cu and Zn), PAH, phthalates, and aliphatic hydrocarbons in the C16–C35 fraction were found in most samples. The results show that the street sweeper collects large amounts of polluted materials and thereby prevents further spread of the pollutants to the receiving stormwater. © 2021 Elsevier B.V.

Sediments in ports, marinas and waterways around the world are often contaminated with metals arising from anthropogenic activities. Regular dredging is needed to achieve an appropriate water depth and reduce the environmental impact of pollutants. The aim of this study was to develop an integrated assessment method for comparing various management strategies for dredged sediments at six case study sites in Sweden. Short- and long-term environmental impacts were investigated for different management approaches, including landfilling, deep-sea disposal, metal extraction in combination with the two aforementioned, and natural recovery (no dredging). The potential value of metals in the sediments was estimated using sediment metal contents and current metal prices. Additionally, an assessment of how metal extraction could result in lower management costs was carried out. The cost of the different management approaches was calculated and evaluated together with the corresponding environmental impacts. This study shows that there is a monetary value in dredged materials, in terms of metal content, and that the materials can potentially be used for metal extraction. Metal extraction may also help to reduce the management costs, as cleaner materials are cheaper to handle. The choice of metal recovery method is important in both monetary and environmental terms, potentially contributing to a circular economy. In the future, metal recovery may become more profitable, as technologies are improved, and due to probable increases in metal prices and landfill costs.

Heavy metal and metalloid contamination of topsoils from atmospheric deposition and release from landfills, agriculture, and industries is a widespread problem that is estimated to affect50% of the EU's land surface. Influx of contaminants from soil to groundwater and their further downstream spread and impact on drinking water quality constitute a main exposure risk to humans. There is increasing concern that the present contaminant loading of groundwater and surface water systems may be altered, and potentially aggravated, by ongoing climate change, through large-scale impacts on recharge and groundwater levels. We investigated this issue by performing hydrogeological-geochemical model projections of changes in metal(loid) (As and Pb) mobilization in response to possible (climate-driven) future shifts in groundwater level and fluctuation amplitudes. We used observed initial conditions and boundary conditions for contaminated soils in the temperate climate zone. The results showed that relatively modest increases (0.2 m) in average levels of shallow groundwater systems, which may occur in Northern Europe within the coming two decades, can increase mass flows of metals through groundwater by a factor of 2-10. There is a similar risk of increased metal mobilization in regions subject to increased (seasonal or event-scale) amplitude of groundwater levels fluctuations. Neglecting groundwater level dynamics in predictive models can thus lead to considerable and systematic underestimation of metal mobilization and future changes. More generally, our results suggest that the key to quantifying impacts of climate change on metal mobilization is to understand how the contact between groundwater and the highly water-conducting and geochemically heterogeneous topsoil layers will change in the future.

Road areas are pollution hotspots where many metals, organic pollutants (OPs) and nano/microparticles accumulate before being transported to receiving waters. Particles on roads originate from e.g. road, tyre and vehicle wear, winter road maintenance, soil erosion, and deposition. Street sweeping has the potential to be an effective and affordable practice to reduce the occurrence of road dust, and thereby the subsequent spreading of pollutants, but there is currently little knowledge regarding its effectiveness. In this paper we investigate the potential of street sweeping to reduce the amounts of OPs and nano/microparticles reaching stormwater, in a case study sampling road dust and washwater from a street sweeping machine, road dust before and after sweeping, and stormwater. The compound groups generally found in the highest concentrations in all matrices were aliphatics C5–C35 > phthalates > aromatics C8–C35 > PAH-16. The concentrations of aliphatics C16–C35 and PAHs in washwater were extremely high at ≤ 53,000 µg/L and ≤ 120 µg/L, respectively, and the highest concentrations were found after a 3-month winter break in sweeping. In general, fewer aliphatic and aromatic petroleum hydrocarbons and PAHs were detected in road dust samples than in washwater. The relative composition of the specific PAH-16 suggests tyre wear, vehicle exhausts, brake linings, motor oils and road surface wear as possible sources. The study indicates that many of the hydrophobic compounds quantified in washwater are attached to small particles or truly dissolved. The washwater contains a wide range of small particles, including nanoparticles in sizes from just below 1 nm up to 300 nm, with nanoparticles in the size range 25–300 nm present in the highest concentrations. The results also indicated agglomeration of nanoparticles in the washwater. The street sweeping collected a large amount of fine particles and associated pollutants, leading to the conclusion that washwater from street sweeping needs to be treated before disposal. Keywords: Road runoff, PAHs, Aliphatics, Particle size distribution, Wet dust sampler, Stormwater

All over the world, elevated levels of metals and the toxic compound tributyltin (TBT) and its degradation products are found in sediments, especially close to areas associated with shipping and anthropogenic activities. Ports require regular removal of sediments. As a result, large volumes of often contaminated sediments must be managed. The aim of this study was to investigate enhanced leaching as a treatment method for organotin (TBT) and metal (Cu and Zn) contaminated marine sediments. Thus, enabling the possibility to reuse these cleaner masses e.g. in construction. In addition to using acid and alkaline leaching agents that extract the OTs and metals but reduce the management options post treatment, innovative alternatives such as EDDS, hydroxypropyl cellulose, humic acid, iron colloids, ultra-pure Milli-Q water, saponified tall oil (“soap”), and NaCl were tested. Organotin removal ranged from 36 to 75%, where the most efficient leaching agent was Milli-Q water, which was also the leaching agent achieving the highest removal rate for TBT (46%), followed by soap (34%). The TBT reduction accomplished by Milli-Q water and soap leaching enabled a change in Swedish sediment classification from the highest class to the second highest class. The highest reduction of Zn was in HPC leached samples (39% removal) and Cu in EDDS leached samples (33% removal). Although high metal and OT leaching were achieved, none of the investigated leaching agents are sufficiently effective for the removal of both metals and OTs. The results of this study indicate that leaching with ultra-clean water, such as Milli-Q water, may be sufficient to treat TBT contaminated sediments and potentially allow mass reuse. © 2021 The Authors

Urban environments are challenged with a plethora of wicked problems in the face of rapid urbanization and land use change, not least natural capital degradation and widespread land and water contamination. Brownfields, under-used sites with real or perceived contamination, are significant urban and peri-urban land resources which, with well-designed remediation and management strategies can address these concerns. Gentle remediation options (GRO) are scalable nature-based techniques which provide significant opportunities for multi-functionality: managing risks posed by contaminants and at the same time enhance ecosystem services (ES) by improving the soil ecosystem in a low-impact, cost-effective manner. GRO align with an increasing interest in taking a holistic view on soil and land management to protect and improve the soil ecosystem for direct human benefit in the form of ES as well as for its indirect, intrinsic value as a haven for biodiversity. This short review aims to present a synthesis of ideas to raise awareness for urban planners about GRO techniques as nature-based solutions which can promote green infrastructure in the urban environment.

Tire and road wear particles have been identified as a potential major source of microplastics in the environment. However, more knowledge of the emissions and their further fate in the environment is needed, and the effectiveness and benefits of potential measures must be investigated to support future risk management efforts. Here the concentrations of tire and bitumen microplastic particles (TBMP) on roads and in nearby in stormwater, sweepsand and washwater were measured for the first time within the same area and time period. The analysis also included plastic, paint and fiber particles. Road dust was sampled on the road surface using a wet dust sampler, before and after street sweeping on two occasions. On each of these occasions, and several occasions during a four-month period with frequent street sweeping, sweepsand and washwater, as well as flow-weighted sampling of stormwater, were collected. TBMP concentrations were operationally defined, using density separation for some samples, followed by analysis by stereo microscopy. Sodium iodide (NaI) was found to be effective for density separation of TBMP. The largest proportion of anthropogenic microplastics detected consisted of tire tread wear and bitumen. The number of TBMP ≥100 μm in the WDS samples was up to 2561 particles/L. Sweepsand and washwater contained high amounts of TBMP ≥100 μm, up to 2170 particles/kg dw and 4500 particles/L, respectively. The results show that the sweeper collects considerable amounts of TBMP, and thus weekly sweeping might prevent further transport of TBMP to the receiving stormwater. In stormwater the number of particles ≥100 μm was up to 3 particles/L and ≥ 20 μm was up to 5900 particles/L showing the importance of analysing smaller microparticle sizes than 100 μm in all samples in future studies. This study also confirms that there is a substantial volume of TBMP generated from traffic that enters the environment. © 2020

Street trees are an important part of urban vegetation due to their provisioning of different types of ecosystem services such as local climate regulation and contribution to aesthetical and recreational values. In order to provide these services, urban trees need to endure many stress factors not present in natural environments, such as the widespread use of impervious surfaces in the vicinity of street trees. However, few studies have evaluated the effect of this potential stress factor on urban tree growth. The aim of this study was therefore to investigate how ground surface permeability affects stem and current-year shoot growth of linden (Tilia europaea) street trees in Gothenburg, Sweden. We found that a small fraction of permeable ground surface in the vertically projected tree crown area caused lower stem growth and strongly suppressed current-year shoot growth. This finding can guide future city planning, demonstrating that the vitality of street trees is compromised when the permeable surface area in the vicinity of the tree is small.

The potential of phytoremediation, as a cost-effective in situ alternative to conventional technologies for remediation of contaminated brownfields, has often been pointed out. Yet, phyto-technologies have failed to find widespread adoption in practice. To gain social and commercial acceptance of these technologies, there is a clear requirement of field studies that provide information on success and failures. The aim of this study was to investigate benefits and potential risks with phyto-stabilisation on brownfields using bioenergy-crops. Two field trials with willow (Salix Klara and Salix Inger) were set up aiming for phyto-stabilisation on metal-contaminated sites. By the use of a tiered risk assessment approach, the cultivation’s effect on ecological risks in different environmental compartments, such as soil, porewater and up-take to biota (including potential risks for wild grazers), was investigated before the cultivation was started and during following three growth seasons. Growth assessments were also made to evaluate the biomass’ potential revenue. The risks to the soil fauna proved to be unchanged or declining. The uptake in the plants was, as aimed for, low to moderate, and the growth rate depended on the soil texture rather than the contamination level of the sites. The low uptake indicated a negligible risk for wild grazers. The field trials were accomplished using no, or low, amounts of amendments, minimum soil interventions, no, or very simple, weeding control and conducted at sites with low annual temperature. Despite harsh conditions, the biomass production was high enough to potentially provide revenue. This study shows that cultivation of brownfields using phytostabilising willow clones can reduce the ecological risks, improve the soil quality of the site and provide revenue if the biomass is sold for e.g. bioenergy production. By choosing phytostabilisation willow clones, potential risks associated with phytoextraction of metals, such as biomass combustion and food chain transfer of metals, were eliminated. Consequently, using bioenergy crops for phytostabilisation on brownfields can contribute to preserve and improve ecosystem services, create economic regeneration of these areas and at the same time be a sustainable risk management option.

International audience; a b s t r a c t Marginal, often contaminated, sites exist in large areas across the world as a result of historic activities such as industry, transportation and mineral extraction. Remediation, or other improvements, of these sites is typically only considered for sites with high exploitation pressure and those posing the highest risks to human health or the environment. At the same time there is increasing competition for land resources for different needs such as biofuel production. Potentially some of this land requirement could be met by production of biomass on brownfield or other marginal land, thereby improving the land while applying the crop cultivation as part of an integrated management strategy. The design and decision making for such a strategy will be site specific. A decision support framework, the Rejuvenate DST (decision support tool) has been developed with the aim of supporting such site specific decision making. This tool is presented here, and has been tested by applying it to a number of case study sites. The consequent SWOT (strength, weakness, opportunities and threats) analysis is discussed and evaluated. The DST was found to be systematic, transparent, and applicable for diverse sites in France, Romania and Sweden, in addition to the sites to which it was applied through its development. The DST is regarded as especially useful if applied as a checklist in an iterative way throughout the decision process, from identifying potential crops to identifying knowledge gaps, working/non-working management strategies and potential risks. The DST also provides a structure promoting effective stakeholder engagement.

Every year flooding and landslides cause severe material damages and thousands of deaths and injuries. To reduce the risk, measures can be taken by applying different management strategies either b ...

Ongoing urban exploitation is increasing pressure to transform urban green spaces, while there is increasing awareness that greenery provides a range of important benefits to city residents. In efforts to help resolve associated problems we have developed a framework for integrated assessments of ecosystem service (ES) benefits and values provided by urban greenery, based on the ecosystem service cascade model. The aim is to provide a method for assessing the contribution to, and valuing, multiple ES provided by urban greenery that can be readily applied in routine planning processes. The framework is unique as it recognizes that an urban greenery comprises several components and functions that can contribute to multiple ecosystem services in one or more ways via different functional traits (e.g. foliage characteristics) for which readily measured indicators have been identified. The framework consists of five steps including compilation of an inventory of indicator; application of effectivity factors to rate indicators' effectiveness; estimation of effects; estimation of benefits for each ES; estimation of the total ES value of the ecosystem. The framework was applied to assess ecosystem services provided by trees, shrubs, herbs, birds, and bees, in green areas spanning an urban gradient in Gothenburg, Sweden. Estimates of perceived values of ecosystem services were obtained from interviews with the public and workshop activities with civil servants. The framework is systematic and transparent at all stages and appears to have potential utility in the existing spatial planning processes.

A consequence of the rapidly increasing demand for bioenergy is an increasing demand for land for growing energy crops. Therefore, the utilization of arable land for this production is believed to increase. Meanwhile, larger areas of arable land are also needed to ensure the supply of food to the growing world population. Growing energy crops in areas that are not suitable for food production such as brownfields, this controversy can partly be solved and several other environmental benefits can be achieved at the same time. The total environmental impact of bioenergy cultivation on contaminated land depends on the full cultivation chain including the handling of bioenergy residues and the full chain is important in the risk- and environmental assessments.

A decision support tool aiming to facilitate discussion and transparency in land-use planning processes has been developed. It includes process steps initiating with an analysis of the current situation, identification of relevant actions and sustainability analysis steps. The sustainability was subdivided into human health and environment, resources, and social and economic impacts. The main difference between this risk analysis tool and others is the allowance of comparisons of present risks and consequences of measures early in the process. It also includes assessments from short- and long-term perspectives, such as taking into account climate change. It combines classic risk analysis with life-cycle assessment procedure. It has been developed and tested in co-operation with municipalities. The tests show that the tool is applicable and can be relevant in the planning process. It offers an iterative discussion framework that is systematic, condensed and yet a simplistic way of describing consequences. ...

Effective landslide risk management requires knowledge of the landslide risks. This paper presents a risk assessment methodology for semiregional scale. The landslide probability is assessed taking into account expected climatechange in the case study area (the G?ta river valley). Climate change is expected to result in increased erosion and water fluctuations. There are large areas with marine clays, often quick clay, in the area and the landslide process can be rapid with extensive damages and casualties. The consequence methodology includes a wide range of consequences assessed by monetary valuation. The consequences and the landslide probability are combined as pairs of values in a risk matrix and the risk is also presented on a map. The map has been used as discussion and decision bases in the municipalities in the G?ta river valley, in the county administration and on governmental level to estimate the needs of risk mitigation and to make priorities.

Landslide risk is a function of the probability of the event and its consequences. Previous research has shown that preventive measures to reduce the risk are preferred over reactive measures but, ...

Natural events such as floods and landslides can have severe consequences. The risks are expected to increase, both as a consequence of climate change and due to increased vulnerabilities, especially in urban areas. Although preventive measures are often cost-effective, some measures are beneficial to certain values, while some may have negative impacts on other values. The aim of the study presented here was to investigate two frameworks used for assessing the effectiveness and sustainability of physical and nonphysical flood and landslide risk reduction measures. The study is based on literature, available information from authorities and municipalities, expert knowledge and experience, and stakeholder views and values. The results indicate that the risks for suboptimization or maladaptation are reduced if many aspects are included and a broad spectrum of stakeholders are involved. The sustainability assessment tools applied here can contribute to a more transparent and sustainable risk management process by assessing strategies and interventions with respect to both short- and long-term perspectives, including local impacts and wider environmental impacts caused by climate change, for example. The tools can also cover social and economic aspects. The assessment tools provide checklists that can support decision processes, thus allowing for more transparent decisions.

Within the scope of this project, tools for conducting systematic and integrated climate vulnerability and sustainability assessments have been developed. Two municipalities in the lower Gota Alv c ...

The increasing need for biomass for energy and feedstocks, along with the need to divert organic methane generating wastes from landfills, may provide the economic leverage necessary to return this type of marginal land to functional and economic use and is strongly supported by policy at the European Union (EU) level. The use of land to produce biomass for energy production or feedstocks for manufacturing processes (such as plastics and biofuels) has, however, become increasingly contentious, with a number of environmental, economic, and social concerns raised. The REJUVENATE project has developed a decision support framework to help land managers and otherdecisionmakersidentifypotentialconcernsrelatedtosustainabilityandwhattypesofbiomass reuseformarginallandmightbepossible,giventheirparticularcircumstances.Thedecision-making framework takes a holistic approach to decision making rather than viewing biomass production simply as an adjunct of a planned phytoremediation project. The framework is serviceable in Germany, Sweden, and the United Kingdom. These countries have substantive differences in their land and biomass reuse circumstances. However, all can make use of the set of common principles of crop, site, value, and project risk management set out by REJUVENATE. This implies that the

The environmental consequences of soil remediation through biofuel or through dig-and-dump were compared using life cycle assessment (LCA). Willow (Salix viminalis) was actually grown in-situ on a discontinued oil depot, as a phytoremediation treatment. These data were used for the biofuel remediation, while excavation-and-refill data were estimated from experience. The biofuel remediation had great environmental advantages compared to the ex situ excavation remediation. With the ReCiPe impact assessment method, which included biodiversity, the net environmental effect was even positive, in spite of the fact that the wood harvest was not utilised for biofuel production, but left on the contaminated site. Impact from the Salix viminalis cultivation was mainly through land use for the short rotation coppice, and through journeys of control personnel. The latter may be reduced when familiarity with biofuel as a soil treatment method increases. The excavation-and-refill remediation was dominated by the landfill and the transport of contaminated soil and backfill.

Though managing vulnerabilities posed by climate change calls for effective strategies and measures, its challenges have hitherto not been fully understood. In Sweden, municipalities have recently ...

Atmospheric water content is important for local and regional climate, and for chemical processes of soluble and solute species in the atmosphere. Further, vapour pressure deficit (D) is one of the key controls on the opening of stomata in plants and is thus an important force for evapotransporation, plant respiration and biomass production and for the uptake of harmful pollutants such as ozone through the stomata. Most meteorological stations typically measure both temperature and relative humidity (RH). However, even if recorded at finer time resolution, it is usually the daily or often monthly means of RH which are published in climate reports. Unfortunately, such data cannot be used to obtain the changes in RH or vapour pressure deficit over the day, as this depends strongly on the diurnal temperature variation during the day and not upon the mean temperature. Although RH typically changes significantly over the day, the ambient vapour pressure is often remarkably constant. Here a simple method to estimate diurnal vapour pressure is evaluated, based upon an assumed constant vapour pressure, and that recorded minimum temperatures approximate dew-point temperatures. With a knowledge of only temperature, we will show that day to day estimates of vapour pressure, humidity and especially D, can be made with reasonable accuracy. This methodology is tested using meteorological data from 32 sites covering a range of locations in Europe. Such a simple methodology may be used to extract approximate diurnal curves of vapour pressures from published meteorological data which contains only minimum temperatures for each day, or where humidity data are not available. Copyright © 2007 Royal Meteorological Society

Coal tar was used in Sweden for the production of asphalt and for the drenching of stabilization gravel until 1973. The tar has high concentrations of polycyclic aromatic hydrocarbons (PAH), some of which may be strongly carcinogenic. Approximately 20 million tonnes of tar-containing asphalt is present in the public roads in Sweden. Used asphalt from rebuilding can be classified as hazardous waste according to the Swedish Waste Act. The cost of treating the material removed as hazardous waste can be very high due to the large amount that has to be treated, and the total environmental benefit is unclear. The transport of used asphalt to landfill or combustion will affect other environmental targets. The present project, based on three case studies of road projects in Sweden, evaluates the consequences of four scenarios for handling the material: reuse, landfill, biological treatment, and incineration. The results show that reuse of the coal tar-containing materials in new road construction is the most favorable alternative in terms of cost, material use, land use, energy consumption, and air emissions.

Quick clay, a soil that changes from normal firm ground to a liquid mass when it is disturbed, has been involved in most of the large and serious clay slides in Sweden, Norway and Canada. The location, time of occurrence and size of quick clay slides are difficult to predict and large slides may cause great devastation. Some geochemical studies of Swedish quick clay were done in the 1960s and early 1970s, but no systematic studies of the interrelationships of pore water chemistry, mineralogy, geotechnical properties and other parameters on quick clays in Sweden have been published. Such studies are of national and general interest because of the many combinations of rock flour source areas and sedimentation conditions that occurred across central Sweden and into the Baltic Sea area during deglaciation. In this study, geotechnical properties related to the in situ chemistry at one quick clay site were extensively studied, and spot sampling was conducted at two other locations in Southwest Sweden. In this area the clay minerals mainly are non-expanding phyllosilicate minerals (illite) and primary minerals (quartz, feldspar), which is consistent with previous studies of quick clay mineralogy. Extensive leaching has occurred at all three locations. At the extensively studied site, Surte, the lowest salinity was found at the greatest depth, inferring that the leaching by fresh water was accomplished by water movement upward and laterally through the sediment from the underlying bedrock. This is consistent with the local setting where bedrock hills rise sharply to over 100 m above the marine sediment surface. An artesian pressure would also be anticipated at this location. There is a correlation (negative) between sensitivity and salinity but there is an indication that the maximum salinity or electrical conductivity consistent with the quick clay behaviour is higher than reported elsewhere. However, for high sensitivities the salinity is about the same as reported elsewhere. In the deepest part of the borehole, there is a higher content of Fe and Al in the pore water, indicating reduced state. Further work is needed to confirm the difference in salinity and to investigate the possible interplay of salinity and potential dispersing agents such as the role of anoxic conditions, in this region. Further work is especially needed in the locations where the sediment accumulation occurred under lower salinity conditions. At all three locations, high remoulded shear strength and low sensitivity have been seen near the surface together with a decrease in pore water cation concentrations.

The magnitude and frequency of nocturnal ozone maxima in a high mid-latitude city (Goteborg, Sweden) has been analysed. Nocturnal ozone maxima have been reported from cities in Europe and North America and can be explained by vertical mixing of high ozone concentrations from higher levels or horizontal transportation from rural areas through local and mesoscale wind systems. Data from four summer months (May–August) in 1994 were used to analyse the relative importance of local- and mesoscale wind systems and vertical mixing in Goteborg during clear and calm weather conditions. Results show that nocturnal ozone maxima frequently occur during these conditions, with a magnitude up to 104 μg m −3 . The nocturnal ozone maxima were positively correlated to both situations with a well-developed land breeze and situations with vertical mixing. During the period investigated, in total 17 nights with secondary ozone maximum occurred. The majority of the secondary ozone maxima (80%) appeared early in the night, i.e. an ozone increase within the first 3 h after sunset and sometimes even two peaks occurred. Seven of these occasions can be explained by horizontal advection, eight by vertical mixing and five cannot by certainty be explained to be due to horizontal or vertical transportation only. During the measurement period the Swedish guideline of 80 μg m −3 (for 1-h value) was exceeded 55% of the days (i.e. 68 days, 557 h) and 33% of the nights (i.e. 41 nights, 103 h) in the central parts of Goteborg. The results thus show that in Scandinavia nocturnal ozone concentrations must be considered.

This paper describes a set of studies which has attempted to make a first estimate of the contribution of biogenic emissions to secondary organic aerosol (SOA) formation over the Nordic countries. The studies comprise first simulations of smog-chamber experiments and second atmospheric modeling. The α-pinene chemical mechanism suggested by Kamens et al. [1999] has been extended for use in regional oxidant models. Inclusion of dimer-formation in this scheme substantially improved performance for some experimental conditions. Although the modified scheme is necessarily tentative, it fits with experimental findings over a wide range of conditions, covering α-pinene concentrations of between 20 and 900 ppb and NOx concentrations of between zero and 240 ppb. The EMEP oxidant model has been used to estimate SOA formation in northern Europe using this chemical scheme and modified gas/particle partitioning methods. The results suggest that biogenic volatile organic compounds (VOCs) contribute far more than anthropogenic VOC to SOA formation. SOA is calculated to be a very variable fraction, between 2 and 50%, of total organic carbon mass in aerosols over the Nordic countries. This fraction is least at coastal sites in southern Norway and Denmark, and much greater for inland sites and sites further north, reflecting the relative distribution of biogenic precursors. There are great uncertainties in these figures, however, and we have had to neglect important primary sources of organic carbon (OC), notably plant waxes, which probably also contribute significantly to total OC. Further progress will be difficult until more measurements are available to characterize the ambient organic aerosol.

The focus in the present study is the spatialvariation of anthropogenic volatile organic carbon compounds (VOC), mainly benzene and toluene, in parks and their built-up surroundings. Case studies were located in two large Scandinavian cities and measurements were made two meters aboveground level in maximum traffic periods. The results showedlarge variations in time and space but despite high pollutionlevels in the streets the air in parks and non-traffickedbuilt-up areas are substantially cleaner. The pollutantconcentration inside a large park decreased to a low level(i.e. 1/3 to 1/9 the concentration at the source) in a shortdistance (

Photochemical ozone creation potentials (POCP) have been calculated under 12 different emission conditions and the replacement of current solvents by oxygenates have been investigated under two European emission conditions. As expected the higher the NO x /VOC ratio, the more pronounced the deviation among POCP values for individual VOC, and the more useful the method of ranking VOC according to their ability to contribute to ozone. The replacement of current solvents by oxygenates significantly reduces the ozone levels in polluted air, such as the London plume. The replacement of current solvents in European air, plumes 1 and 2 in Poppe et al. (1996) and Kuhn et al. (1998), has a limited effect on the ozone levels. The influence on other species such as PAN and aldehydes is, however, also, under these conditions, significant when replacing current solvents by oxygenates.

This article describes the results of a chemical comparison between the 140-reaction EMEP MSC-W chemical scheme and a much more comprehensive chemical mechanism, the IVL scheme with over 1800 reactions between 714 species. The schemes have been compared in detail for three different emission scenarios. One scenario describes the air in a London plume and the others correspond to more moderately polluted air masses typical of regional scale ozone formation. Comparisons of the simulated concentrations of ozone have been further conducted in an isopleth of chemical environments where the emissions of NOx and VOC have been varied over a wide range. The simulated concentrations of ozone and most photochemical species are found to compare well with the chemical descriptions for all scenarios. This analysis differs from similar previous comparisons in that (1) we investigate the changes in ozone resulting from changes in emissions of nitrogen oxides and groups of hydrocarbons, i.e. alkanes, alkenes, aldehydes, alcohols and aromatic species, and (2) we analyse the main mechanisms underlying the model results in order to illustrate how the similarities and differences of the two schemes influence the ozone simulations. Overall we conclude that the EMEP chemistry gives a description of ozone formation and the effects of emission control measures which is in good agreement with that given by the much more comprehensive IVL chemistry.

Quick clay may be stabilised by increased magnesium concentrations in the pore water. Weathering has so far been cited as the source of magnesium, but is an unlikely process at 15 m depth in clays, where an increase was found at a test site in the south of Sweden. This study investigates how far ion exchange can explain the source of magnesium. A rough model in the program PHREEQC incorporating ion exchange, but not weathering, is used to model geochemical and transport processes since the latest ice age in a soil profile in the Gota River valley. Rain water, or rain water with added calcium or magnesium carbonate, is used as infiltrating solution. Calcium or magnesium could come from weathering in the dry crust. Advection, diffusion and ion exchange are sufficient to approximate concentrations in the pore water, if the infiltrating water contains calcium. Weathering at depths below 5 m is not included in the model, but observations of magnesium are reproduced nevertheless. The magnesium comes from the sea water at the end of the latest ice age and has been stored on the ion exchange sites in the clay. The magnesium is displaced into the pore water when calcium enters the soil, is transported downwards, and partly re-enters the exchange sites. The rough model supports the importance of ion exchange for the restabilisation of quick clay by natural magnesium at this site.

An emission inventory concerning volatile organic compounds (VOC) and their emission profile linked to their sources in Sweden has been undertaken. The inventory has been used in model simulations to predict the ozone formation from different emission source categories in Sweden. The studies have been carried out using the IVL photochemical trajectory model for two types of air masses which describes clean and polluted air. In Sweden mobile sources contribute to 45 % by mass of the total national VOC emissions, 58 % of the NOx emissions and to at least 43 % of the ozone formation from national sources. In general, the ozone formation in Sweden is more dependent and sensitive to emissions of NOx rather than VOC.

Photochemical ozone creation potentials (POCP) have been calculated for 75 organic compounds and carbon monoxide. The creation potentials are calculated using different concepts; peak ozone concentrations and the average formation of ozone, including the amount deposited, during two or four days. The calculations were made by a single-box trajectory model with meteorological and chemical conditions chosen to correspond to a summer high-pressure situation in southern Sweden. Under these conditions, over a 96-hour average, POCPs show that ethene and acrolein are the most efficient ozone producers, followed by higher alkenes, aromatics, alkanes and ethers which can be considered as mediate ozone producers. Chlorinated species, alcohols and ketones are very weak producers of ozone. The relative POCPs differ depending on the method of calculation and the chemical (NOX) environment.

Lower toxicity and less pollution is the goal of all soil remediation. We are willing to spend money and time to achieve this. And our action of treating the soil causes new pollution in its turn.

For over two decades, models from EMEP MSC-W1 have been used to aid governments in their design of control strategies to reduce air pollution in Europe. Indeed, EMEP long-range transport models (e.g. Eliassen and Saltbones, 1983) played a key role in even the first UN-ECE2 Protocol on sulphur, signed in Helsinki in 1985. Modelling demonstrated that sulphur could be transported many 100s of km from the source, and was used to quantify the contribution of each country to acid deposition across Europe. The sulphur model developed in this early work has been steadily extended and improved to give today’s EMEP models for acidification, ozone and most recently aerosols.