Electrokinetic monitoring of synthetic geoclay liners

Abstract On-going work and preliminary results are presented from impedance spectroscopy investigations of sodium bentonite. The purpose of the work is to find out if alternating electric current measurements might be utilised for monitoring the conditions of synthetic geoclay liners. Theoretical analyses as well as preliminary results indicate that sufficient alteration in the signal might be obtained for variation in moisture content, salt content and location, as desired. The results also indicate that the impedance spectroscopy method is applicable for the understanding of the microstructural aspects of bentonite.

Sustainability of combustion and incineration of renewable fuels : example of Sweden

According to the statistics at the EC Commission, Sweden is the Champion byfar in Europe in terms of renewable energy. It comprised around 45% of the totalin the year 2008. This position has been reached by a combination of naturalresources, political determination and technology development.A major contributor to this is the extensive utilization of district heatingwhich amounts to around 50 TWh per year, and which covers about half of thetotal need for industrial and domestic buildings. The district heating is basedmainly on combustion of bio fuels together with waste and some peat.This practice is generally very positive from a sustainability perspective forthe following reasons: (1) bio fuels are renewable, and so is peat, although over alonger time span; (2) waste is being recovered for energy purposes; and (3) ashmaterial is, in many cases, re-circulated and recycled.However, sustainability is not only about total percentages, but also on thequality in the processes, especially in terms of qualification of fuels and ashesand the associated possibilities for more efficient combustion and incinerationprocesses as well as ash utilization. Efficiency in this regard of course alsoincludes protection of health and the environment. These aspects are explored ina technical as well as a legal perspective, and some possibilities for furtherdevelopment and improvement are identified and discussed.The compilation and analyses are based on more than ten years of researchreports (mostly in Swedish) financed by District Heating in Sweden (SvenskFjärrvärme), [The Swedish] Thermal Engineering Research Institute(Värmeforsk), the Swedish Waste Management (Avfall Sverige) and SvenskaEnergiaskor AB (which translates to: “Swedish Energy Ashes Inc.”).Validerad; 2013; 20131030 (rolsjo

Classification of ash as hazardous or non-hazardous waste

Combustion and incineration are utilized extensively in Sweden for the generation of heat and electricity. Substantial volumes of ash with varying chemical composition are also generated in the process. Classification of such ash as hazardous or non-hazardous under the European union legislation is, in principle, a “mission impossible” since the chemical forms of the inorganic components are very complex. Consequently, a method has been identifiedaccording to which reference substances are selected such that they represent the hazards of the actual forms of those trace elements that might influence health and the environment. The reference substances have been selected such that the hazard is not underestimated, that the result becomes reasonable realistic and that the evaluation is feasible to carry out. There areindications, especially with regard to ecotoxicity, that the method is overly cautious, and a potential is identified for combining testing with information from Authority data bases. It is explained and exemplified that ash may be very susceptible to ageing, and that this in many cases, and for most of the elements of interest, may improve the properties considerably. This not only influences the status of an ash with regard to the acceptance criteria for landfilling, butalso influences the classification. Leach properties are important when the degree of solid solution is to be assessed. Elements with similar properties, especially regarding their ionic radii, tend to exchange for each other even in solids. The effect is strongest for those elements that are the lowest abundance. Solid solution effects may lead to that trace elements become as inaccessible as the major elements in a certain crystalline phase. Iron(hydr)oxides and other ironrich phases frequently act as sinks for chromium, nickel and zinc, and in many cases this implies that most of these elements may not contribute to a classification as hazardous. The method has been applied to around 30 facilities with typically several ashes at each facility. It is concluded that this approach has lead to that many ashes have been classified in a cautious bur also reasonably realistic manner which at the same time has been practical.Godkänd; 2014; 20150523 (rolsjo

Alunframställning och att lära av historien

Godkänd; 2015; 20151022 (rolsjo)</p

Molecular reorientations in some hydrogen bonded solids

Proton magnetic resonance second moments and relaxation times at various temperatures are reported for tri- and dimethyl ammonium iodide, bromide, chloride and hydrogen oxalate, and for most of the twenty common amino acids. A general procedure is described for the calculation of theoretical second moments and relaxation times in dipolar solids. In several cases, this procedure is applied to determine the molecular reorientations present as well as the corresponding activation barriers. The results are discussed with particular reference to hydrogen bonding

Molecular reorientations in some hydrogen bonded solids

Proton magnetic resonance second moments and relaxation times at various temperatures are reported for tri- and dimethyl ammonium iodide, bromide, chloride and hydrogen oxalate, and for most of the twenty common amino acids. A general procedure is described for the calculation of theoretical second moments and relaxation times in dipolar solids. In several cases, this procedure is applied to determine the molecular reorientations present as well as the corresponding activation barriers. The results are discussed with particular reference to hydrogen bonding

Long-term developments in residues from the processing of alum shale and possible remedies

In large parts of the world, the gas market has changed dramatically due to the fracking of rock, including shale. It is also anticipated that significant changes will take place in the oil market due to the rapid introduction of the processing of shale for the purpose of oil and gas generation. Many fear that there will be substantial consequences for the environment, especially in the long term. The purpose of the present paper is to share some experiences from related historical activities in Sweden where alum shale has been used for oil extraction, burning of lime, alum production and uranium beneficiation. Legacies exist in terms of shale ash and fines as well as residues from the leaching of uranium, in quantities of a total of tens of millions of tonnes, and at various stages of remediation. The long-term integrity of these residues is analyzed with regard to the possibility of development of acid mine drainage, and in view of the low Ca and high S content. It is found that such developments cannot be excluded for the cases in which the alum shale had not been (properly) combusted. Waste materials having appropriately high pH acid buffering capacities to inhibit acidification are identified together with injection as a promising method of application. The need for mixing on a local scale is discussed together with the possible influence of the injection of slurry on ongoing fires. It is found that further knowledge is needed on a number of issues.Godkänd; 2014; 20140424 (andbra