Impact of free calcium oxide content of fly ash on dust and sulfur dioxide emissions in a lignite-fired power plant

Emitted pollutants from the Agios Dimitrios lignite-fired power plant in northern Greece show a very strong linear correlation with the free calcium oxide content of the lignite ash. Dust (fly ash) emissions are positively correlated to free calcium oxide content, whereas sulfur dioxide (SO2) emissions are negatively correlated. As a result, at present, the Agios Dimitrios Power Plant operates very strictly within the legislative limits on atmospheric particulate emission. In the present study, the factors to be considered in assessing the impact of lignite combustion on the environment are presented and evaluated statistically. The ash appears to have a remarkable SO2 natural dry scrubbing capability when the free calcium oxide content ranges between 4 and 7%. Precipitator operating problems attributable to high ash resistivity can be overcome by injecting sulfur trioxide to reduce the ash resistivity, with, of course, a probable increase in operating costs.     

Bioindication of air pollution effects near a copper smelter in Brazil using mango trees and soil microbiological properties

A field study near the copper smelter of a large industrial complex examined air pollution effects on vegetation and soil parameters in Cama?ari (northeast Brazil). Close to the smelter, soil pH-value was lower and total acidity as well as organic carbon contents were higher compared with a site far from the source and two reference sites. The acidification of top soil particularly and the drastically enhanced plant-available copper concentrations were caused by atmospheric deposition. High sulphur and copper deposition significantly reduced microbial biomass and altered functional diversity of soil microorganisms (arylsulphatase and xylanase). Large accumulations of sulphur, arsenic and copper were detected in mango leaves (Mangifera indica) growing downwind from the smelter suggesting potential food chain-mediated risk.     

Atmospheric phase distribution of oxidized and reduced nitrogen at a forest ecosystem research site

Atmospheric concentrations of gaseous NH3 and HNO3 and of particulate NH4+ and NO3- were measured during various seasons at a forest ecosystem research site in the "Fichtelgebirge" mountains in Central Europe. Air masses arriving at this site were highly variable with respect to trace compound concentration levels and their concentration ratios. However, the distributions of NH4+ and NO3- within the aerosol particle size spectra exhibited some very consistent patterns, with the former dominating the fine particle concentrations, and the latter dominating the coarse particles range, respectively. Overall, the particulate phase (NH4+ + NO3-) dominated the atmospheric nitrogen budget (particulate and gas phase, NH4+ + NO3- + NH3 + HNO3) by more than 90% of the median total mixing ratio in winter, and by more than 60% in summer. The phase partitioning varied significantly between the winter and summer seasons, with higher relative importance of the gaseous species during summer, when air temperatures were higher and relative humidities lower as compared to the winter season. Reduced nitrogen dominated over oxidized nitrogen, indicating the prevailing influence of emissions from agricultural activity as compared to traffic emissions at this mountainous site. A model has been successfully applied in order to test the hypothesis of thermodynamic equilibrium between the particulate and gas phases.     

Inheritance of migratory direction in a bird species: a cross-breeding experiment with SE- and SW-migrating blackcaps (Sylvia atricapilla)

Summary Young avian migrants of many species are able to find their species- or population-specific wintering area without the help of conspecifics. In orientation tests hand-raised birds have been demonstrated to choose appropriate population-specific migratory directions, suggesting a genetic basis to this behaviour. I here report results of a cross-breeding experiment between individuals of two blackcap (Sylvia atricapilla) populations with widely different migratory directions. The orientation of the F1 offspring was intermediate between and significantly different from that of both parental populations (Fig. 2). The variance of individual mean directions in the F1 generation did not increase compared with the parental groups, and the inheritance of migratory directions was not sex-linked. The data provide direct evidence for a genetic basis of migratory directions in birds and demonstrate a phenotypically intermediate mode of inheritance.     

Ecology of<Emphasis Type="Italic"> Leptothorax</Emphasis> ants: impact of food,nest sites,and social parasites

In a long-term field manipulation, we demonstrate strong reactions of Leptothorax longispinosus ant colonies to food- and nest-site supplementation. Demographic and genetic responses varied over small geographic scales, and the two ecological factors interacted with the presence of the social parasite Protomognathus americanus. We conducted a 2×2 experiment in three blocks and found that the blocks, which were less than 100 m apart, reacted very differently to the treatments. Blocks differed in degree of polygyny, intranest relatedness, colony size, productivity, and sexual investment. Furthermore, these differences were associated with the presence of slave-making ants and the local availability of nest sites. Nest-site supplementation had a strong effect only in the site with the highest prevalence of social parasites, influencing there the density and investment patterns of colonies. L. longispinosus ants in the least parasitized area were strongly affected by both food- and nest-site supplementation. There, food supplementation led to a decrease in the number of queens per colony and consequently to an increase in intranest relatedness, while colonies in nest-site-supplemented areas invested fewer resources in males and produced a female-biased allocation ratio. By contrast, in a third block with a very low intracolonial relatedness, food supplementation induced an absolute and relative higher investment in males. We conclude that ecological factors influencing social organization in insect societies cannot be studied in isolation, because the interactions among factors produce far richer responses than any one variable.Communicated by L. Sundström     

Hochwasser 2002

In August 2002, highly contaminated areas in the region of Bitterfeld, e.g. the floodplain of the creek Spittelwasser, as well as the adjacent regions of Jeßnitz and Raguhn, were submerged by the river Mulde. An input of mobilized contaminated sediments in residential areas was the matter of concern. The objective of the present study was to estimate the pollutants load on the basis of chemical and biological data and identify the sources of pollutants. Deposited sludge and flood water samples were assessed on the basis of biological and chemical analyses and in comparison with administrative reference values. The pollution of the investigated sites was rather heterogeneous. At several sites, tolerance limits of the German Klärschlammverordnung or the Bundesbodenschutzverordnung were clearly exceeded, e.g. for Pb, As and HCH. Organic extracts exhibited significant effects in several biotests. This may be relevant with respect to direct particle uptake via ingestion or respiration. Pollution patterns for heavy metals as well as for organic pollutants differed significantly from the pattern found in the Spittelwasser flood plain before the inundation, which is in contrast to the initial hypothesis of a possible transport of contaminated Spittelwasser sediments into residential areas. Interestingly, a correlation of chemical load and the overall biological effect could be shown. From the viewpoint of the precautionary principle, the identification of the compounds exerting toxic effects and of the respective pollutant sources would be desirable.     

Anwendung energetischer und nicht-energetischer Ressourcen in Energiesystemen: Vergleichende Bewertung

Goal and Scope

Which impact does the use of non-energetic abiotic resources (ores, minerals, etc.) have in life cycles of energy systems based on biogenic and fossil fuels? Is this kind of resource use less or more environmentally harmful than the utilisation of energetic abiotic resources (mineral oil, natural gas, etc.) in the same life cycles? This paper aims at answering these questions. In Part 1, a methodology is presented and applied to the life cycles of selected energy systems. Part 2 presents and discusses the results.

Methods

The applied methodology has been explained in the Part 1. For the assessment of energetic abiotic resource use, a widely recognised method is used. For the assessment of nonenergetic abiotic resource use, no overall recognised methodological approach exists. That is why for this aspect two different methods are exemplarily applied and compared with each other.

Results and Conclusion

Results show that the two assessment approaches for non-energetic resource utilisation lead to qualitatively equal results. Nevertheless they differ considerably from each other in their absolute values. This makes obvious that there is still a need for further methodological research work on that issue. Nevertheless, both methodologies yield that the accumulated effect of ore and mineral use is considerably lower than the accumulated effect of fossil primary energy utilisation in all life cycles analysed. With the assumptions made, the use of non-energetic abiotic resources only plays a comparatively subordinate role in the environmental life cycle assessment of energy systems based on biogenic and fossil fuels.

Recommendation and Perspective

Results suggest that an important resource-related impact of biomass and fossil fuel powered energy systems is caused by their consumption of fossil primary energy resources. The impact of non-energetic resource use can be neglected in comparison to that. At the same time, results also make clear that there is still a considerable need for further methodical research aiming at a standardised assessment methodology for the use of non-energetic abiotic resources.