Alkoxy-silyl Induced Agglomeration: A New Approach for the Sustainable Removal of Microplastic from Aquatic Systems

The substance class of inert organic-chemical stressors (IOCS) describes organic-chemical (macro-) molecules, which demonstrate a high level of persistence upon entry in the ecosystem, and whose degradation is limited. These synthetically produced organic-chemical macromolecules, which are often derived from the polymerization of different monomers, are, in the form of plastics, indispensable in the everyday world. They enter the environmental compartments and cause great damage due to primary (industry, cosmetic, washing of textile), and secondary (degradation) entry. If these particles get into aquatic systems, this has fatal consequences for the ecosystem such as the death of marine animals, or bioaccumulation. Wastewater treatment plants are reaching their limits and require innovative ideas for the sustainable removal of microplastic. This article examines a new approach to the removal of polymers from aquatic systems (lab scale) by using sol–gel induced agglomeration reactions to form larger particle agglomerates. These enlarged agglomerates can be separated much more easily from the wastewater, since they float on the water surface. Separation systems, e.g. sand trap can easily be used. A further advantage is that the agglomeration can be carried out completely independently of the type, size, and amount of the trace substance concentration as well as of the external influences (pH value, temperature, pressure). Thus, this new type of particle separation can not only be used in sewage treatment plants, but can also be transferred to decentralized systems (e.g. implementation in industrial processes).

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Deposition Loads of Sulphur and Nitrogen in Germany

High spatial resolution maps of deposition loads in Germanyare produced as an input for abatement strategy research andfor critical loads exceedance calculations on a nationalscale. In this paper methods ofmapping total deposition loads in Germany and preliminarymaps of nitrogen and sulphur deposition loads for the year1993 are presented. A comparison of these mapping resultswith EMEP deposition mapping results has been carried out.The differences in the results of the German national and theEuropean EMEP mapping, due to different databases anddifferent methods, are quantified and discussed. Highresolution maps of deposition loads are compared to Europeanlow resolution maps on the same temporal and spatial scale,assuming that on average both should lead to similar results.However, the average differencescalculated for 23 EMEP 150 × 150 km² grid cells over Germanywere found to be 33% higher for sulphur (S) total depositionby the German method 65% higher for S dry deposition and1% lower for S wet deposition. The German results fornitrogen (N) total deposition are 2% higher than the EMEPresult 22% higher for N dry deposition and 10% lower for Nwet deposition.     

TIMBER HARVEST IMPACTS ON SMALL HEADWATER STREAM CHANNELS IN THE COAST RANGES OF WASHINGTON1

ABSTRACT: We evaluated changes in channel habitat distributions, particle‐size distributions of bed material, and stream temperatures in a total of 15 first‐or second‐order streams within and nearby four planned commercial timber harvest units prior to and following timber harvest. Four of the 15 stream basins were not harvested, and these streams served as references. Three streams were cut with unthinned riparian buffers; one was cut with a partial buffer; one was cut with a buffer of non‐merchantable trees; and the remaining six basins were clearcut to the channel edge. In the clearcut streams, logging debris covered or buried 98 percent of the channel length to an average depth of 0.94 meters. The slash trapped fine sediment in the channel by inhibiting fluvial transport, and the average percentage of fines increased from 12 percent to 44 percent. The trees along buffered streams served as a fence to keep out logging debris during the first summer following timber harvest. Particle size distributions and habitat distributions in the buffered and reference streams were largely unchanged from the pre‐harvest to post‐harvest surveys. The debris that buried the clearcut streams effectively shaded most of these streams and protected them from temperature increases. These surveys have documented immediate channel changes due to timber harvest, but channel conditions will evolve over time as the slash decays and becomes redistributed and as new vegetation develops on the channel margins.     

Die organisation der Früherkennung von Umweltproblemen im Rahmen der wissenschaftlichen Beratung der Umweltpolitik

This study is based on the theses that

1. early diagnosis is indispensable in the context of precautionary policy for the management of environmental problems which have the character of a “creeping disaster”, and that
2. the public must play the active role that is adequate within a democratic society.

In the context of the study, three existing advisory committees for environmental policy as well as two concepts which have not been put into effect are investigated. The third part deals with the critique of these committees and an alternative concept of early diagnosis “General Ecological Monitoring” which has not yet been put into effect. In part I, the concept of the Picht commission from 1972, which has never been realized in this form has been introduced. In part II, the concepts and the working method of the three existing advisory committees (SRU, WBGU, TAB) have been presented. In part IV, the work of the oldest of the committees, the SRU, is examined with respect to the three most important environmental problems of the last 15 years.     

Gesellschaftlicher Wandel und nachhaltige Entwicklung

Background, aim, and scope In order to assess the effects of social change from the point of view of sustainability the article considers demographic, social and cultural developments. Taking the sectors ‘Building and Housing’, ‘Infrastructure Systems’ and ‘Mobility and Transport’ as examples, it outlines visible trends and describes the possible scope for actions and instruments to achieving sustainably social change. Main features Demographic change, social-cultural change, extent of social change in Schleswig-Holstein, the sectors ‘Building and Housing’, ‘Infrastructure Systems’, and ‘Mobility and Transport’, environmental impact of social change. Results From the point of view of sustainability the essential kriterion is not so much the size of the population in absolute terms as consumer habits, which are subject to numerous influences. One important characteristic of the evolution from the industrial to the post-industrial society is a pluralization of lifestyles, with the associated consumption patterns, in sectors relevant to sustainability. Discussion A diversity of technologies is available for reducing the environmental burden. They influence thermal insulation of buildings, electricity and water sparing, domestic appliances and fuel-efficient vehicles with controlled catalytic converters. The use of these technologies rather depends on cultural and economic trends as well as political decisions than on technical feasibility. Conclusions If no actions occur to counteract them, the effects of social change on the environment will be immense. There will be no ‘demographic benefit’, and neither can the sustainability balance of the postmaterialists be considered more favourable than that of people with a materialistic attitude. Recommendations and perspectives Political groups should address the problems raised by social change, analyze their effects and initiate a comprehensive social process of dialogue and agreement with the players concerned. Quick solutions are not to be expected, since the complexity of the subject, the different interests involved and the large numbers of issues to be regulated require perseverance and a time frame that goes beyond a single legislative period.     

The Effect of Nitrogen Enrichment on the Carbon Sink in Coniferous Forests: Uncertainty and Sensitivity Analyses of Three Ecosystem Models

Estimates of the global carbon sink induced by nitrogen enrichment range vary widely, from nearly zero to 2.3 Gt C year^-1. It is necessary to reduce this uncertainty if we are to make accurate predictions of the future magnitude of the terrestrial carbon sink. Here, we present a Monte Carlo approach to uncertainty and sensitivity analysis of three ecosystem models, Century,BGCand Hybrid. These models were applied to a coniferous forest ecosystem in Sweden. The best estimate of the change in total carbon content of the ecosystem with the cumulative change in nitrogen deposition over 100 years, C_total/N_deposition was 20.1 kg C (kg N)^-1 using the pooled mean, with a pooled standard deviation of 13.8 kg C (kg N)^-1. Variability in parameters accounted for 92% of the total uncertainty in C_total/N_deposition, and only 8% was attributable to differences between models. The most sensitive parameters were those which controlled the allocation of assimilate between leaves, roots and stem. In particular, an increase in allocation to fine roots led to a large reduction in C_total/N_deposition in all models, because the fine roots have a very high turnover rate, and extra carbon allocated there is soon lost through mortality and decomposition.     

Lagrangian dispersion modeling of vehicular emissions from a highway in complex terrain

Transit traffic through the Austrian Alps is of major concern in government policy. Pollutant burdens resulting from such traffic are discussed widely in Austrian politics and have already led to measures to restrict traffic on transit routes. In the course of an environmental assessment study, comprehensive measurements were performed. These included air quality observations using passive samplers, a differential optical absorption spectroscopy system, a mobile and a fixed air quality monitoring station, and meteorological observations. As was evident from several previous studies, dispersion modeling in such areas of complex terrain and, moreover, with frequent calm wind conditions, is difficult to handle. Further, in the case presented here, different pollutant sources had to be treated simultaneously (e.g., road networks, exhaust chimneys from road tunnels, and road tunnel portals). No appropriate system for modeling all these factors has so far appeared in the literature. A prognostic wind field model coupled with a Lagrangian dispersion model is thus presented here and is designed to treat all these factors. A comparison of the modeling system with results from passive samplers and from a fixed air quality monitoring station proved the ability of the model to provide reasonable figures for concentration distributions along the A10.