Process industry, construction and other comparable activities produce large quantities of waste with potential use in geotechnical applications. Prior to utilisation, an acceptably low risk of contamination to humans and the environment must be demonstrated. This work focuses on the identification and evaluation of critical factors for environmental assessments of secondary construction materials. The market potential and the main barriers for usage of industrial wastes were analysed and showed a good potential especially in urban areas. The main obstacle is the long and complicated permit process involved. Further, the lack of a general procedure to investigate the suitability of intended usage leads to inconsistent assessments. An evaluation of leachate emissions from a large-scale test road demonstrated the importance of construction design and site-specific field conditions on the potential environmental impacts. It was also shown that pollutant concentrations in leachate from secondary construction materials tend to become comparable, or for some pollutants, even lower than from rock materials. Different assessment methods and criteria to judge the acceptability of an intended use were reviewed and various methods were identified. However, a generic method to evaluate materials under various environmental conditions is lacking. / Godkänd; 2004; 20070109 (mlk)

This thesis investigates the use of plants, fungi, and microorganisms to assess and treat landfill gas, leachate and contaminated soils. As landfill emissions can occur over extended time periods, it is a practical strategy to develop passive and economical methods for emission control i.e., requiring little human involvement. Organisms can play an important role in such methods if their living requirements can be met, e.g., adequate temperature or moisture content. A broader understanding of how organisms respond to and are affected by pollution may be used to develop landfill design strategies and engineering technologies that favour bioremediation. A secondary benefit is that a greater knowledge of organism response may be used to determine the pollution state of a site. Methanotrophic bacteria in the soil can be used to identify methane emission areas. An assay method was developed, based on the pressure change induced by methane oxidation. The fungus Telephora caryophyllea accumulates arsenic.The method could be sufficient to delimit arsenic contaminated areas. Landfill vegetation is exposed to pollutants and can indicate their presence. Despite high species diversity, no damages to the vegetation, due to the presence of pollutants,could be observed. The oxidation capacity of the studied soil is sufficient to completely oxidise the methane emissions at old and small landfill sites. Even though the oxidising capacity is sufficient, non-optimal conditions result in methane emission peaks. Wetlands can reduce the nitrate concentration in leachates. In the cold climate regions studied at least four years are needed to have a fully established vegetation cover and degraded organic material. A 30% reduction of nitrate was attributed to denitrification. However a precise mass balance is needed to accurately evaluate the treatment capacity. Vegetation at the investigated site may used to immobilise soil contaminants such as Cu, Zn, Pb, and As. However, the application of soil amendments is recommended to reduce foliar accumulation of contaminants. / Syftet med avhandlingsarbetet var att undersöka huruvida växter, svampar och mikroorganismer kan användas för att indikera respektive behandla deponigas, lakvatten och förorenad jord. Eftersom emissioner från deponier sker under lång tid, är det nödvändigt att utveckla passiva och billiga metoder för emissionskontroll, dvs sådana som kräver lite mänsklig inblandning. Vissa organismer kan spela en viktig roll i sådana metoder, såvida de har goda livsbetingelser, dvs att deras krav på t ex temperatur, näring och fukthalt är uppfyllda. Utformning och drift av deponier kan utvecklas för att gynna denna typ av passiva biologiska behandlingar. En kartläggning av föroreningssituationen kan erhållas genom att studera organismers reaktion på densamma. Följande potentiella användningsområden för bioindikation och -sanering har studerats:Metanoxiderande bakterier i marken kan användas för att indikera metanemissioner. En indirekt mätmetod har utvecklats, som är mindre känslig för plötsliga emissionsvariationer över tiden än direkta mätmetoder. Metoden baseras på mätningen av den tryckförändring som resulterar från metanoxidationen. Längden på perioden innan metanoxidationen når sin maximala nivå används som indikator för metanemissioner. Perioden förkortades när jorden tidigare exponerats för metan. En inkubationstemperatur av 30°C och en vattenhalt motsvarande fältkapaciteten rekommenderas. Svampen Telephora caryophyllea tar upp arsenik från förorenad mark och kan indikera arsenikföroreningar i jorden. Mätbara halter av arsenik kunde påvisas efter lakning av svampen med ammoniumacetat och efterföljande färgtest, som tar några minuter. Användning av metoden kan vara tillräcklig för att avgränsa ett arsenikförorenat område. Deponivegetationen exponeras för föroreningarna och kan indikera dessa. Trots täckskiktets stora artrikedom kunde inte några skador på vegetationen upptäckas, som orsakats av förekomsten av Cu, Zn, Pb, As, metan och koldioxid. Detta beror troligtvis på att den naturliga vegetationen är tolerant mot dessa föroreningar. Metanoxidationskapaciteten hos de undersökta jordarna (upp till 24.6 mol metan år-1 kg-1 TS jord) är tillräcklig för att oxidera all metanemission från gamla eller små deponier. Trots att kapaciteten är tillräcklig, resulterar icke optimala förhållanden i metanemissionstoppar, t.ex. när marktemperaturen är låg eller marken torr. Eftersom metanoxiderande bakterier lever i den övre delen av täckskiktet, är de utsatta för olika klimatförhållanden. Lakvattenbevattning kan begränsa torka i avfallsupplagets täckskikt och har alltså en positiv effekt på metanoxidationen. Våtmarker kan minska nitrathalten i lakvatten. Höga kanter runt våtmarksanläggningar i kallt klimat leder till att ett extra 50 cm isolerande snötäcke kan bildas. Trots detta var vattentemperaturen lägre än 5°C under mer än en tredjedel av året. Högt vattenstånd efter planteringen och ett tunt jordlager gynnar växtetableringen. Minst fyra år behövs för att få en etablerad vegetation som genererar vissna växtdelar, vilka kan användas av mikroorganismer för t ex denitrifikation. En 30-procentig nitratminskning kunde erhållas tack vare denitrifikation. Det finns dock en osäkerhet i beräkningen och en noggrann massbalans behövs för att utvärdera behandlingskapaciteten. Vegetationen på det undersökta området skulle kunna användas för att binda t.ex. Cu, Zn, Pb och As i sina rötter. Dock rekommenderas användning av tillsatser för att binda föroreningarna i jorden och minska transporten av dessa till bladmassan. Trots förekomsten av det zink-hyperackumulerande gräset Thlaspi caerulescens på området, rekommenderas inte phytoextraktion, eftersom arten har låg biomassaproduktion och andra föroreningar förekommer (Cu, Pb och As). / Godkänd; 2001; Bibliografisk uppgift: Därtill 7 uppsatser.; 20060915 (pafi)

Godkänd; 1998; 20070404 (ysko)

No description available.

Increasing amounts of incineration residues need to be disposed, reused or treated, which calls for reliable characterisation methods. Leaching tests are often used for an assessment of release of pollutants from wastes under a variety of leaching factors. Nevertheless, the prediction of the contaminants release in field is difficult due to the complexity of the processes occurring in field. This work aims at evaluating limitations and possibilities of making long- term leaching predictions for incineration residues using diffusion leaching tests. Also the effect of carbonation on the leaching of elements was evaluated. Leaching predictions for Cl and Pb based on diffusion test data were compared with leachate data from MSWI bottom ash reused in road construction as well as leachate data obtained using a two-step compliance test. For the first years, leaching of Cl from bottom ash in field could be predicted with an accuracy within one order of magnitude. This could be considered as a good fit. Good agreement was also found between leaching predictions based on the diffusion test and the compliance test for Pb. However, predictions based on a diffusion tests might be misleading for longer time periods as the stock of contaminants depletes. Longer time series of field data are needed for comparison. Field conditions such as wet/dry and freezing/thawing cycles were not considered in this work, but might affect the mobility of contaminants. The impact of such field factors deserves a thorough examination in future research. Carbonation was found to significantly affect leaching of some elements from MSWI bottom ash. Leaching of Pb and Zn was increased due to carbonation, while leaching of Cr, Mo, and Sb decreased. Leaching of Cu was increased by carbonation alone, but it was also observed that leaching could be decreased if carbonation is combined with water-solidification. With such effect on leaching it is necessary to take carbonation into account when leaching predictions are made. / Godkänd; 2004; 20070127 (ysko)

Municipal solid waste incineration fly ash is often landfilled or sent abroad for stabilization because it is considered a hazardous waste. These approaches to fly ash are both costly, and highlight the need for alternative and sustainable ash recycling. Both the needs of waste recycling and preservation of natural resources can be solved by using fly ashes as a secondary construction material and as soil fertilizer.Three types of fly ashes have been investigated in the laboratory experiments. Namely municipal solid waste incineration (MSWI), refuse-derived-fuel (RDF) and biofuel fly ashes. Factors influencing changes in chemical properties and mineralogical composition of RDF fly ash exposed to environmental conditions close to those that are found in a landfill top cover were evaluated in the accelerated ageing experiment. Element availability to leaching and plant uptake in soil amended with MSWI, biofuel fly ashes and biosolids was also evaluated.RDF fly ash exposed to the conditions found in a landfill top cover (20% CO2, 65% RH, 30°C T) lead to the chemical and mineralogical transformations that resulted in reduced leaching of most of the elements studied here. Only concentrations of Cl- in the leachates were an issue, because they still exceeded the leaching limit values; nevertheless the leaching of this element in aged ash decreased by 50% compared to fresh ash.Application of pelletized MSWI fly ash with biosolids on soil resulted in elevated total concentrations of As, Cd and Pb in soil (by 29%, 100% and 300%), but dissolved concentrations of these elements in soil pore water, except the As, were low as in the range of drinking water concentrations (98/83/EC). Furthermore, the concentrations of Cd and Pb in plant biomass were negligible regardless of the type of ash used.Based on the observations, RDF fly ash is considered as a suitable material to be used in a landfill liner. Whereas MSWI and biofuel fly ashes based on element availability for plants studies, could be considered suitable for land applications. But doses to be applied on soil should be adjusted to the type of ashes used to avoid accumulation of potentially toxic elements in soil over time. / Godkänd; 2013; 20130827 (evebra); Tillkännagivande disputation 2013-10-04 Nedanstående person kommer att disputera för avläggande av teknologie doktorsexamen. Namn: Evelina Brännvall Ämne: Avfallsteknik/Waste Science and Technology Avhandling: Suitability of Fly Ash for Construction and Land Applications Opponent: Associate Professor Alessandra Polettini, University of Rome ”La Sapienza”, Rome, Italy Ordförande: Professor Anders Lagerkvist, Institutionen för samhällsbyggnad och naturresurser, Luleå tekniska universitet Tid: Fredag den 25 oktober 2013, kl 10.00 Plats: F1031, Luleå tekniska universitet

Anthropogenic induced nutrients in the Baltic Sea have led to 97% of it being eutrophic. Phosphorus is regarded the main regulating nutrient, and nearly 25% of the nutrients coming to the Baltic Sea originate from wastewater treatment plants. To reduce the nutrient concentrations in the effluents from treatment plants, tertiary treatment methods based on chemical dosing have been the principal answer. The chemicals create a sludge in addition to remediating the water, which needs disposal. Methods for remediating secondary wastewater with microalgae exist but are not common in conventional wastewater treatment. However, using microalgae could be beneficial, since they use inorganic carbon (from the atmosphere and wastewater) and inorganic nutrients, while producing biomass and oxygen. The biomass in turn has a potential to be used in production of bioenergy, food, and fertilizers.  This thesis investigated whether pre-phosphorus starvation of five different microalgae strains enhanced the removal rate of phosphorus from secondary wastewater. The aim was to determine the optimal starvation period of different algae strains and to achieve wastewater effluent concentrations below 0.1 mg/L at the shortest possible time. Algae were transferred to a phosphorus-free media for five, three, one and zero days before entering the wastewater in a batch reactor at a temperature of 27°C and a 16:8 hours light and dark regime. Phosphate and nitrate concentrations as well as biomass production were monitored during a period of ten days. The experiment was repeated three times using Chlorella Vulgaris and two times using Tetradesmus Obliquus, Ankistrodesmus Falcatus, Botryococcus Braunii and one time using Desmodesmus Communis. The secondary wastewater was obtained from a small wastewater treatment plant from the village Roja in Latvia. Prior to the experiments, it was filtered three times through filters with different pore sizes (the smallest pore size was 0.2 µm), and the average nitrate and phosphate concentrations were 21.3 ± 1.1 mg/L and 17.8 ± 0.56 mg/L, respectively. The nitrate to phosphate ratio was 1.8:1. It was possible to remove the inorganic phosphorus to concentrations below 0.1 mg/L within ten days, although it did not happen in all the reactors. It was found that in most cases pre-phosphorus-starvation increased the removal rate of phosphorus. For two of the strains, Chlorella Vulgaris and Ankistrodesmus Falcatus, the three-day of pre-starvation period was optimal, while two to three days was optimal for Tetradesmus Obliquus, compared to other pre-starvation periods. For Botryococcus Braunii the one-day and the zero-days starved batches removed the phosphorus most efficiently. For Chlorella Vulgaris and Ankistrodesmus falcatus nearly a 100% of the phosphorus was removed within seven days after three days of pre-starvation. Without pre-starvation, these strains achieved the same result after ten days. It was also found that the nitrogen was the limiting nutrient in the wastewater and that the different strains responded differently to the changes in environment brought on by the experiment. When using microalgae in wastewater treatment, the choice of strain greatly impacts the removal rate, as the likeliness for them to survive in a specific environment varies among strains. It was concluded that using microalgae as a wastewater treatment method could pose great benefits. However, more experiments with colder climate, non-pre-filtered wastewater, a less nutrient rich media, greater initial biomass concentrations and pilot tests are recommended. Another insight from this thesis was that the method for transferring algae between different media needs to be refined to reach the target concentration in a reactor (or other setup).

Decision-making in environmental issues often includes uncertainty in the input data and the resulting uncertainty when the data is used. Some spatial decisions are however taken without any formal analysis, meaning that the decision-makers have a mental map and preconceived notions about the decision options before the final decision actually is taken. An example of such decision situation is siting of new landfills, where there is no standard method to aid in the decision-making process today. In other decision situations, the methods and criteria may be well developed. A commonly used method for investigation contaminated sites in Sweden is called "MIFO"- Method of Surveying Contaminated Sites. In MIFO investigations start at a superficial level and after each phase, efforts are focused further on the brownfields with highest priority. A strict model has advantages as resources are prioritized at the most polluted sites. But having a static model with strict guidance also leads to problems as the sampling approach suggested by the model is not optimally adapted to individual sites. The risk is that contamination is overestimated or underestimated, leading to unexpected costs as well as waste of resources in a remediation situation. Variability of the data, uncertainty in the data quality and the consequences in having no versus strict guidance in a decision situation are discussed in two cases; a regional landfill siting project, and a local investigation of a contaminated site. Future research involves how to include uncertainty modelling as a standard in all environmental decision-making processes. Tools are needed to aid decision-makers in expressing the maximum accepted uncertainty in the outcome. Guidance for selecting and weighing of criteria in decision- situations must be developed, as well as models that consider the case specific demands and conditions. / Godkänd; 2004; 20070131 (ysko)

Godkänd; 1997; 20070418 (ysko)

No description available.