Combining Leaching and Passive Sampling to Measure the Mobility and Distribution between Porewater, DOC and Colloids of Native Oxy-PAHs, N-PACs and PAHs in Historically Contaminated Soil

Different methods to quantify soil porewater concentrations of contaminants will provide different types of information. Passive sampling measurements give freely dissolved porewater concentrations (Cpw,free), while leaching tests provide information on the mobile concentration (Cpw,leach), including contaminants associated with dissolved organic carbon (DOC) and particles/colloids in the porewater. This study presents a novel combination of these two measurements, to study the sorption and mobility of polycyclic aromatic compounds (PACs) to DOC and particulate organic carbon (POC) in 10 historically contaminated soils. The PACs investigated were polycyclic aromatic hydrocarbons (PAHs), oxygenated-PAHs, and nitrogen containing heterocyclic PACs. Observed Cpw,leach was up to 5 orders of magnitude higher than Cpw,free; implying large biases when Cpw,leach is used to assess bioavailability or soil partitioning. Sorption of PACs to DOC and POC was important for the mobility of compounds with log KOW > 4. Average DOC/water-partitioning coefficients (KDOC) correlated well with KOW (log KDOC = 0.89 × log KOW +1.03 (r2 = 0.89)). This relationship is likely more accurate for historically contaminated soils than previously published data, which suffer from artifacts caused by problems in measuring Cpw,free correctly or not using historically contaminated soils. POC/water-partitioning coefficients (KPOC) were orders of magnitude larger than corresponding KDOC, suggesting sorption to mobile particles/colloids is the dominant mechanism for PAC mobility

ENCORT-CDW - Evaluation of the European recovery target for construction and demolition waste

The present EU target for recovery of construction and demolition waste does not promote sustainability. Interpretations of waste and recovery definitions rather than resource efficiency and safe handling affect the monitoring. The general weight-based target has to be altered to favour recycling of resource-rich materials, not only of high weight materials. High grade recycling should be distinguished and prioritized to ensure safe recovery. This requires improved knowledge on waste generation and handling as well as on emissions of dangerous substances. A common Nordic approach is advocated

Magnetic susceptibility for assessing ash constructions : Evaluating the potential of magnetic susceptibility as a method to assess state and delineation of ash constructions

Vägar och andra anläggningar byggda med askor erbjuder miljöfördelar i form av resurssnålare och i vissa fall effektivare konstruktioner än konventionella material. Men, förekomsten av miljöstörande ämnen i askor ger även upphov till risker om de kommer i kontakt med omgivningen. Projektet syftar till att undersöka om magnetiserbarhet kan användas för att bedöma askkonstruktioners tillstånd och avgränsning. Hypotesen är att askorna har en högre magnetiserbarhet än de material som täcker dem och att man genom att mäta magnetiserbarheten i en volym som innefattar såväl det överliggande materialet som askan, kan bedöma tillståndet (tjockleken eller uppblandningsgraden) hos materialen. Därför har ett 20-tal olika material slaggruser, flygaskor, grusslitlager och jordarter undersökts samt två fältlokaler karterats. Projektet är ett samarbete mellan VTI och SGI. Roads and other constructions built with ash can be more effective than conventionally built roads. But since there also can be certain pollutants connected to ashes, using ashes in constructions can pose a threat to the environment if they are not contained within the construction. This project is aiming to investigate if magnetic susceptibility can be used in order to appraise the state of ash constructions. The hypothesis is that the ashes have higher magnetic susceptibilities than the material that is supposed to be on top of the ash. If so, it is suggested that, by measuring the magnetic susceptibility of a volume including both the overlying material and the ash, the state of the overlying material can be estimated (thickness and/or grade of mixture with the ash). Therefore some 20 different material were investigated and two field sites mapped. Miljöriktig användning av asko

Particle dispersion at road building using fly ash : Model review, investigation of influence of humidity content for dust emission and fly ash particle characterisation

Aska från förbränning kan ha mycket goda egenskaper såsom byggnadsmaterial i vägkroppar. Denna användning förutsätter dock att askan inte har några allvarligare miljö- och hälsoeffekter. Då aska kan damma kraftigt vid hantering har frågan om damningens omfattning och dammets egenskaper visat sig vara av stor betydelse för att bedöma riskerna för miljöpåverkan vid användning. Inandningsbara partiklar i vår omgivningsluft är ett problem som uppmärksammas alltmer och betraktas som en av våra allvarligaste hälsorelaterade föroreningar. Föreliggande projekt har haft som syfte att: beskriva lämpliga modeller för beräkning av emission och spridning av aska i luften vid byggnation av väg där aska ingår utvärdera en ny metod att undersöka fukthaltens betydelse för damning från flygaska undersöka egenskaper hos flygaska som gör det möjligt att identifiera aska i prover av luftburna partiklar. Målgruppen är askleverantörer, entreprenörer och konsulter med behov av kunskap om askors damning. Projektets delmoment har omfattat: en litteraturstudie för att identifiera lämpliga modellverktyg för att beskriva emission och spridning av damm från vägbyggnation med aska en metodstudie där en utrustning kallad Duster, har utvärderats för att bedöma betydelsen av askans fuktighet för damning, samt en elektronmikroskopstudie där morfologi och sammansättning hos några askor, cement och Merit har studerats för att finna sätt att identifiera askpartiklar i dammprover.Ashes from incineration may have very good properties, such as building materials in roads. This use assumes that the ashes do not have serious environmental and health effects. Since ash might generate large amounts of dust in handling the issue on the extent of dusting and dust properties has proved to be important to assess the risks of environmental impacts during use. Inhalable particles in the ambient air are a problem that has attracted much attention and is regarded as one of the most serious health related air pollutants.  The present project has aimed to:  describe appropriate models for calculating the emission and dispersion of dust in the air during the construction of ash containing roads,  evaluate a new method to examine the importance of moisture for dusting from fly ash and  investigate the properties of fly ash, making it possible to identify ash in samples of airborne particles.  The target audience is ash manufacturers, contractors and consultants with a need for knowledge of ash dusting. Project modules have included:  a literature review to identify appropriate modelling tools to describe the emission and dispersion of dust from road building with ash  a method study in which a piece of equipment called Duster, have been evaluated for assessing the significance of the ash humidity to dusting, and  an electron microscope study where morphology and composition of some ashes, cement and Merit have been studied to find ways to identify ash particles in dust samples.Miljöriktig användning av asko

How Does the European Recovery Target for Construction &Demolition Waste Affect Resource Management?

The revised EU Waste Framework Directive (WFD) includes a 70 % target for recovery of construction and demolition (C&D) waste. In order to study the potential change in the resource management of the main C&D waste fractions, as a consequence of fulfilling the WFD target, a Nordic project (ENCORT-CDW) has been performed. Waste fractions studied included asphalt, concrete, bricks, track ballast, gypsum-based construction materials and wood. Recovery scenarios were identified and estimations were made regarding expected savings of primary materials, impact on transport, and pollution and emissions. For wood waste, the main differences between re-use, material recycling and energy recovery were evaluated in a carbon footprint screening based on life cycle assessment methodology. The study concluded that the EU recovery target does not ensure a resource efficient and environmentally sustainable waste recovery in its present form since: It is very sensitive to how the legal definitions of waste and recovery are interpreted in the Member States. This means that certain construction material cycles might not count in the implementation reports while other, less efficient and environmentally safe, recovery processes of the same material will count. • It is weight-based and consequently favours large and heavy waste streams. The result is that smaller flows with equal or larger resource efficiency and environmental benefit will be insignificant for reaching the target. • It does not distinguish between the various recovery processes, meaning that resource efficient and environmentally safe recovery cannot be given priority. Improved knowledge on C&D waste generation and handling, as well as on content and emissions of dangerous substances, is required to achieve a sustainable recovery.publishedVersio

Dust emissions from gravel roads built with fly ash

Obundna vägar dammar genom trafikens framfart över dem. Sådan damning kan leda till trafiksäkerhets- och hälsorisker, olägenheter för närboende och ett accelererat nedbrytande av grusvägens slitlager. Det har funnits misstanke om att grusvägar där bärlagret stabiliserats med inblandning av flygaska skulle damma mer än konventionella grusvägar. Därför undersöktes damningen vid två fältlokaler där både asksträckor och konventionellt byggda sträckor fanns. Forskningsuppgiften var att jämföra damningen och svara på frågan om askvägar dammar mer än de konventionellt byggda vägarna. Dessutom skulle spridningen av damm till omgivningen kartläggas och förekomsten av aska i det uppvirvlade dammet detekteras. Projektet genomförs som ett samarbetsprojekt mellan VTI, SGI och Högskolan Dalarna, men även IVL har varit med i projektgruppen. Resultaten riktar sig till planerare och drift- och underhållsansvariga hos väghållare, entreprenörer och myndigheter. Fältmätningarna har innefattat såväl väletablerade som innovativa mätmetoder för bestämning av damning och sådana faktorer som påverkar damning som grusslitlagrets vattenkvot och kornstorleksfördelning. Unpaved gravel roads will emit dust when trafficked. Such dust emissions might lead to traffic safety and health issues as well as nuisance to the neighborhood and accelerated deterioration of the gravel surface course. It has been suspected that gravel roads with fly-ash stabilized base courses might cause larger dust emissions than conventionally constructed gravel roads. Therefore two field sites with both ash stretches and conventional stretches were investigated. The task was to compare the dust emissions and answer the question whether ash roads emit more dust than conventional gravel roads. Further, the emissions of dust to the surrounding were to be monitored and the occurrence of ash in the suspended dust was to be detected. The project was conducted in cooperation between VTI, SGI and Högskolan Dalarna and with the Swedish Environmental Institute as part of the research group. Miljöriktig användning av asko

Ackumulering av metaller i vegetation på geotekniska askkonstruktioner

Resultaten från denna studie tyder på att åldrat slaggrus som används utblandat med planteringsjord (här 50 vikt-%), till exempel i sluttäckningsändamål, inte ger upphov till betydande förhöjda metall- och metalloidhalter i engelskt rajgräs under en växtsäsong jämfört med vanliga anläggningsmaterial (här schaktmassa och bergkross). Studien visar även på vikten av att ta hänsyn till damning och partikelkontaminering som exponeringsväg då risker relaterat till ackumulation av metaller i ekosystem och exponering för betande djur via växtupptag utvärderas. Minimering av partikelspridning bör vara en viktig beståndsdel vid utformning av skyddsåtgärder då askor används i geotekniska konstruktioner. Slutligen visar studien att de generella akumuleringsfaktorer för upptag till växter som ligger till grund för beräknigar av riktvärden i Naturvårdsverkets Handbok 2010:1 om återvinning av avfall i anläggningsarbeten inte är lämpliga för användning i samband med riskbedömning av askor

End-of-Waste Criteria for Construction & Demolition Waste

This report presents the situation within the Nordic countries with respect to production and recycling of construction and demolition waste, in particular crushed concrete, in the form of aggregates, and discusses the conditions and requirements relating to environmental impacts for a possible application of the End-of-Waste option in the Waste Framework Directive. If this option is applied, the material may become a product and it will no longer be regulated by waste legislation. Regulation of crushed concrete under product legislation presents a number of challenges, particularly with respect to environmental protection. The report presents and proposes a methodology for the setting of leaching and risk-based criteria to be fulfilled by crushed concrete (and other waste aggregates) in order to obtain End-of-Waste status. It is further recommended to set impact-reducing conditions on the use of materials obtaining End-of-Waste criteria, and not to allow free use. It should be noted that the work described in this report was carried out during the period from 2010 to 2012