Verlauf der Fließgewässer auf dem Stadtgebiet von Freiburg und im Übergangsbereich zu den angrenzenden Landkreisen Breisgau-Hochschwarzwald und Emmendingen. Die Gewässer sind aufgeteilt in Fileßgewässer 1. und 2. Ordnung sowie Sonstige Fließgewässer und Gräben.
This is the Editorial to a Special Issue entitled "Cyanobacterial blooms. Ecology, prevention, mitigation and controlŁ. The Special Issue is a product of a European COST Action, CYANOCOST. In this Special Issue, contributions describe methods currently available for the management of cyanobacterial blooms, a key issue threatening the ecological functioning of lakes and the ecosystem services they provide . Contributions start with a section on the prevention of blooms, through the restriction of nutrient availability for cyanobacterial development at three levels: (1) in the catchment, (2) at the inflow to the lake and (3) in-lake methods, including nutrient release from the sediment. Then follows a section on control of blooms where blooms could be formed in the lake, but the chosen treatment restricts cyanobacterial growth to a level where risks and negative effects are minimal, e.g., artificial mixing, flushing or biomanipulation. The Special Issue continues with contributions on mitigation where blooms do develop, but physical and chemical methods mitigate the negative effects. For effective control key traits of the dominant cyanobacteria, characteristics of the lake system and an adequate design of the control method must come together. Each contribution answers questions like: what is the proposed or proven working mechanism of a given method? What have been the successes and failures? What are the reasons for success or failure? How is success linked to characteristics of the waterbody being treated? The Special Issue is concluded with contributions aiming at social and political aspects of bloom management .<BR>Quelle: http://link.springer.com
Lake Tegel and Schlachtensee in Berlin show a uniquely pronounced trophic recovery in response to an abrupt and drastic (40- to 100-fold) reduction of their external phosphorus (P) load through P-stripping at their main inflow which exchanges the lake water volume about 5 times per year for Lake Tegel and about 1.5 times for Schlachtensee. Veröffentlicht in Texte | 45/2011.
Sensor cell lines have been developed to monitor rapid non-genomic signalling cascades influenced by endocrine-active substances. These in-vitro bioassays were created by genetically modifying G-protein coupled estrogen receptor (GPER1) expressing cells to become artificial fluorescent signalosomes. Both GPER1 agonists and antagonistic compounds were used to characterize the respective sensor cells. The bioassays were then used to screen for potential endocrine-disrupting substances. In addition, these assays have been used to evaluate influent and effluent from advanced treatment units in several wastewater treatment plants. Veröffentlicht in Texte | 132/2024.
Resources, including minerals and metals, underpin the world's economies for almost all sectors, providing crucial raw materials for their industrial processes. Despite efforts to decouple economies from resource use towards a circular economy, demand for extractive resources will continue to grow on the back of emerging economies. The report maps existing international governance frameworks and initiatives which have overlapping subsets that focus on delivering the 2030 Global Agenda for Sustainable Development. In this report, the International Resource Panel (IRP) of the UN Environment Programme highlights that the mining sector, if carefully managed, presents enormous opportunities for advancing sustainable development, particularly in low-income countries. As discussed in Chapter 5, extractive industries place large demands on natural resources such as land and water. Its activities can lead to polluting water resources, biodiversity loss and ecosystem destruction including land degradation and desertification. Therefore, there is a need to look at the dynamic relationships between mining, and land and water. This calls for a systems-thinking approach that accounts for the nexus between resources so as to steer policy efforts towards integrated natural resource management along the mining value chain. The report maps existing international governance frameworks and initiatives which have overlapping subsets that focus on delivering the 2030 Global Agenda for Sustainable Development. It presents the practical actions required to improve the international governance architecture for mining to enhance its contribution towards sustainable development. It calls for a new governance framework for the extractive sector referred to as the "Sustainable Development Licence to Operate" which includes consensus-based principles, policy options and best practices that are compatible with the Sustainable Development Goals and other international policy commitments. Minerals and metals underpin national economies, provide crucial raw materials for industrial activities, and are inputs to almost every sector of the global economy. Demand for extractive resources will continue to grow on the back of emerging economies with expanding and increasingly affluent and urban populations and a global transition towards low-carbon but metal-intensive energy production technologies. This is despite efforts to decouple economies from resource use and towards greater recycling. The frequently severe and enduring environmental impacts of mining highlight the need to carefully balance such activities with stewardship of other valuable natural resources and the environment including ecosystems and biodiversity, and the rights of local people and communities. Decision-making in the extractive sector is shaped by a complex array of governance frameworks and initiatives operating along highly globalized mineral value chains. There is an urgent need to coordinate and reform this governance landscape to address enduring challenges such as commodity price volatility, lack of linkages between mining and other economic sectors, inadequate management of environmental impact, and socio- and geopolitical risks of mining. The report maps over 80 existing international governance frameworks and initiatives which focus on delivering overlapping subsets of the 2030 Global Agenda for Sustainable Development, but do not currently operate in a sufficiently coordinated or integrated manner. In this context, the report calls for a new governance framework for the extractive sector referred to as the "Sustainable Development Licence to Operate" and includes consensusbased principles, policy options and best practices that are compatible with the Sustainable Development Goals and other international policy commitments. The report discusses practical actions to improve the international governance architecture for mining to enhance its contribution towards sustainable development. The proposals include reaching an international consensus regarding the normative content and structure of the Sustainable Development Licence to Operate informed by expert inputs from a "Highlevel Panel on Mining for Sustainable Development". It further considers the creation of an International Mineral Agency to share relevant information and data. Governments could also reach bilateral and plurilateral agreements regarding security of supply of raw materials and resource-driven development. Periodical reporting of progress towards sustainable development could be enabled through a Global "State of the Extractive Sector" review or equivalent process. Quelle: Verlagsinformation
Lake Tegel is an extreme case of restoration: inflow treatment reduced its main external phosphorus (TP) load 40-fold, sharply focused in time, and low-P water flushed the lake volume ~ 4 times per year. We analysed 35 years of data for the time TP concentrations took to decline from ~ 700 to 20-30 (my)g/l, biota to respond and cyanobacteria to become negligible. The internal load proved of minor relevance. After 10 years, TP reached 35-40 (my)g/l, phytoplankton biomass abruptly declined by 50% and cyanobacteria no longer dominated; yet 10 years later at TP < 20-30 (my)g/l they were below quantifiable levels. 20-25 years after load reduction, the lake was stably mesotrophic, macrophytes had returned down to 6-8 m, and vivianite now forms, binding P insolubly in the sediment. Bottom-up control of phytoplankton through TP proved decisive. Five intermittent years with a higher external P load caused some 're-eutrophication', delaying recovery by 5 years. While some restoration responses required undercutting thresholds, particularly that of phytoplankton biomass to TP, resilience and hysteresis proved irrelevant. Future research needs to focus on the littoral zone, and for predicting time spans for recovery more generally, meta-analyses should address P load reduction in combination with flushing rates. The Author(s) 2020
Water has been seeping into the Asse II mine for decades, resulting in a risk of what is known as “drowning”. Miners use this term to describe a situation in which so much water enters a mine that it is no longer safe to work in it and the mine must be abandoned. Around 12 cubic metres of solution per day are currently seeping into the mine through cracks in the surrounding rock and salt. This volume is equivalent to about 50 bathtubs. Even the experts from the BGE cannot predict how the rate of influx will vary over time, and it could change at any time in such a way that safe operation of the mine was no longer possible. In this case, the retrieval of radioactive waste would have to be abandoned. On this page Causes and background Not all water is the same How is the salt water monitored? How is the salt water disposed of? Will the disposal options remain constant? Is there no better way to seal the mine? Questions and answers Over decades of intensive salt mining, miners created numerous cavities in a very confined space, especially on the southern edge of the salt structure. These cavities are permanently exposed to rock pressure and are being slowly but steadily compressed. The movement of the rock creates cracks that allow water to penetrate into the mine. A blessing in disguise: the penetrating water contains large quantities of salt. Experts describe this as a saturated rock salt solution, meaning that the solution cannot dissolve any new rock salt and thereby enlarge the flow pathways. Rock salt is the term used by miners to refer to sodium chloride, also known as common salt. There are also other types of salt, such as various potassium salts. Incidentally, the amount of water in the mine is independent of the amount of rainfall above ground, because the water first travels through the rock for very long periods of time before penetrating into the mine. In other words, we don’t collect more water underground in times of higher rainfall. Diagrams : Intensive salt mining has left its mark on the Asse II mine. The resulting cavities were later largely backfilled, thereby stabilising the facility. The diagrams show all the cavities that ever existed in the Asse II mine – which were never open at the same time – as well as the mine in 2015, when numerous cavities had already been filled in . There are around 570 spots in the Asse II mine that are slightly damp or dripping. These spots often dry up on their own. In other places, the BGE collects the solution on a continuous basis. The most important collection point is the so-called main collection point at a depth of 658 metres (see diagram). This point is located around 100 metres above the emplacement chambers containing radioactive waste at the 750-metre level. At the main collection point, the BGE experts are currently collecting around 95% of the salt solution leaking into the Asse II mine (type A solution). This had no contact with the radioactive waste. An additional 1 cubic metre of salt water per day is collected below the main collection point (type B solution). This solution also had no contact with the radioactive waste. Further down in the mine, salt water that has come into contact with the radioactive waste and is contaminated is also collected. This comes to a small amount, averaging around 15 litres per day (type C solution). No matter where the BGE collects the solution, it undergoes intensive analysis. Among other things, checks are made of the following: volume of influent solution salt content temperature density. The solution is also analysed for radioactive substances, with tritium playing a particularly important role in this context. Tritium is a radioactive variant of hydrogen and originates from the stored waste. As this radioactive substance is gaseous and so small, it can escape from the emplacement chambers through extremely fine cracks and is absorbed on contact with the underground solution. However, measurements show that the solution from the main collection point (type A solution) contains only around a tenth of the quantity of tritium that would be permitted in drinking water. The collected salt water also contains traces of other radioactive substances that originate from the surrounding rock and have been absorbed by the water on its way through the rock mass. These substances are of natural origin and have nothing to do with the nuclear waste in the Asse II mine. The solution collected at the main collection point and cleared from a radiological perspective leaves the Asse II mine every three weeks. It is handed over to a certified specialist company from the chemical industry in order to recycle the salt. The solution is radiologically harmless. The solution arising at other collection points remains in the mine and is generally not radioactively contaminated. It is used in the mine to produce concrete, which the miners use to fill in residual cavities with a view to stabilising the mine. If the solution can only be collected after it has come into contact with the radioactive waste (type C solution), this usage is only possible to a limited extent. If the radioactive contamination is comparatively low, the BGE also uses this solution to make concrete in the deepest areas of the mine. This procedure has been authorised by the state mining office and ensures that the radioactive substances contained in the concrete no longer reach the surface. If the solution has a higher level of contamination, however, it is declared as radioactive waste and handed over to the state collection point of Lower Saxony. This rarely happens, however, and only applies to a few litres of solution. The BGE is constantly exploring other disposal options. It is important to do so because the mine can only be operated safely in the long term if the solution can be handed over on a regular basis. For example, the BGE currently only hands over type A solution, which is collected above the 700-metre level and is well below the limit value for tritium in the Drinking Water Ordinance. This voluntary commitment can only be met if the quantity of solution arising does not increase significantly below the 700-metre level. Since significantly larger quantities of water cannot be utilised underground, a disposal option would then have to be identified outside the Asse for type B solution in order to ensure continued safe operation of the mine. Since type B solution also has no contact with the waste, radiological clearance appears to be possible. Ultimately, the requirements of the Radiation Protection Act are decisive when it comes to the disposability of the solutions. Stabilisation work There is no way to seal the mine so that no more solution can enter. This is because the rock on the southern flank has been extensively loosened by rock displacement into the mining areas, and blocking one route would lead a new one to break open. It is important to stabilise the mine, and the BGE therefore backfills all cavities that are no longer required for the recovery of radioactive waste. This causes the mine to deform more slowly, as empirical values have already shown. It is impossible to predict how long the mine can be operated safely. An important prerequisite for the retrieval of waste is that the main collection point can be operated in a stable manner or alternative methods can be found for salt water management. Salt water has been flowing into the Asse mine since 1988. So far, a large part of this salt water has been collected at a depth of 658 metres at the so-called main collection point. This salt water is then tested for possible radiological contamination and pumped above ground. The situation has changed since the start of the year, and a greater volume of salt water is now being collected at several points below 658 metres than at the main collection point. Most of the radioactive waste lies at a depth of 750 metres. It is located in the former mining chambers of the old salt mine, which dates back more than 100 years. A measuring programme is being deployed there to check whether salt water comes into contact with the waste and therefore becomes contaminated. The measurements at the 750-metre level currently give no indication of an increase in contaminated solutions. There is no evidence that contaminated salt water reaches the surface, nor is this to be expected in the immediate future. Based on current knowledge, it would take several hundred years for radioactive substances to reach the surface. It is impossible to make a detailed calculation of the potential level of radiation exposure in the future, as this depends on the exact course of release. Possible scenarios range from exposure below the permissible limits to a slight exceeding of the limits. A large-scale evacuation is not to be expected. The BGE is continuing to pursue the retrieval of radioactive waste, and planning is ongoing. The BGE will only be able to say how current events affect retrieval planning once it has more information on how current events unfold and the plans have been reviewed accordingly. The BGE has been implementing precautionary measures to stabilise the mine for years. These precautionary measures are part of emergency planning and constitute a prerequisite for the retrieval of radioactive waste. Cross-flooding the mine is part of the emergency measures set out in the emergency planning. These measures will be implemented if the influx of solution increases to such an extent that it is no longer technically controllable. This is not currently the case. At present, miners are gradually working their way into the main collection point at the 658-metre level within the secured area in order to locate potential damaged areas of containment liner that are accessible and to carry out appropriate repairs. In April 2024, the BGE made an application for complete renovation of the main collection point at the 658-metre level. This project will be pursued further. The application has been submitted to the State Office for Mining, Energy and Geology (LBEG), which is the competent authority in this instance. As part of the application, the BGE requested that the LBEG allow necessary exploratory work to begin in advance of renovation based on a partial licence.
The BGE adjusts its discharge request for the Bergmannssegen Hugo mine to the strict drinking water limit value s 13 March 2018 The Bundesgesellschaft für Endlagerung (BGE) has once again amended its discharge request for the Bergmannssegen Hugo mine near Sehnde. Instead of applying the legally permissible limits of the Radiation Protection Ordinance, the BGE wants to discharge salt solution from the Asse mine into the mine only if the limits remain below the values of the Drinking Water Ordinance. The BGE had committed itself to this anyway. At the suggestion of the State Office for Mining, Energy and Geology (LBEG) in Lower Saxony, it has now adapted the discharge request. Ursula Heinen-Esser, Chair of the Management Board of the BGE said: “From the very beginning, we have committed ourselves to making use of the permit only if we succeed in continuing to stay below the drinking water limit value with the Asse salt solutions. There will be no discharge of contaminated solutions at any time. Such discharge is prohibited by law”. Before the rock-salt-saturated groundwater is discharged, it is tested for radioactive substances. Every delivery is checked. The reference nuclides are tritium and caesium-137. The measurement is carried out within the framework of a release procedure according to Section 29 Radiation Protection Ordinance. Only when radiological safety has been proven in this release procedure may the salt solutions be discharged. Samples are also tested for all components every three months. The analysis of trace elements should indicate the smallest changes in the composition of the solution. The measurements show that the tritium concentration is far below the limit value of the Drinking Water Ordinance. The Drinking Water Ordinance prescribes a limit value of 100 becquerels per litre (1 becquerel = 1 nuclear decay per second). The rock-salt-saturated groundwater to be discharged has a tritium concentration of 2 to 5 becquerels per litre. Caesium-137 was not detected. The measured values are published regularly. You can find them on our website: www.bge.de/de/meldungen/2018/1/asse-messwerte-der-abtransportierten-zutrittswaesser-2017/ (German only) Background: Since 1988, groundwater has been seeping into the Asse mine. Currently, there are about 12,500 litres of salt water (salt solution) per day. Of this, about 11,500 litres are collected at the 658-metre level about 100 metres above the radioactive waste and pumped away from there. These salt solutions do not come into contact with the radioactive waste and must be disposed of. Until the end of 2016, the solution was discharged into the Mariaglück mine near Höfer in the district of Celle. The influent salt solutions are currently being recycled industrially. The main customer for the influent salt solution is currently an industrial company that uses the rock salt solution as a raw material for further production processes. The Bergmannssegen Hugo mine is the back-up option in case the customer cannot accept the salt solution because of production or if more salt water enters the mine. In letters to the citizens’ initiative and during an explanation of the plans in the environmental committee of the city of Sehnde, we have already offered that the city or a group of citizens can commission an institute of their choosing to carry out their own measurements of the salt solutions. The offer still stands: The BGE will cover these costs if you want to take advantage of it. The BGE is doing everything it can to ensure that an emergency at the Asse II mine does not occur and thus jeopardise the retrieval of the radioactive waste. But this emergency is also not ruled out. The BGE must be prepared for this. The Bundesgesellschaft für Endlagerung (BGE) is seeking a site for a repository for high-level radioactive waste and building the Konrad repository for low- and intermediate-level radioactive waste. The BGE is keeping the Morsleben repository open until decommissioning and is planning the retrieval of the radioactive waste from the Asse II mine. The BGE is a federally owned company within the portfolio of the Federal Environment Ministry. Its managing directors are Ursula Heinen-Esser (Chair), Dr Ewold Seeba (Deputy Chair), Professor Hans-Albert Lennartz (Commercial Manager) and Dr Thomas Lautsch (Technical Manager).
The worlds industrialised nations have accumulated a wealth of assets in the form of buildings, infrastructure and other durable goods. These assets constitute a valuable reservoir of secondary raw materials. This "anthropogenic material stockŁ should be understood as a future capital stock that must be systematically managed and exploited. Yet this capital stock has hitherto been largely ignored in discussions on resource efficiency, which instead have focused on inputs of primary raw materials. This is partly due to insufficient knowledge of the size and constitution of this material stock as well as its dynamics. Therefore, a project was set up by Germanys Federal Environment Agency to provide the missing information. Project results offer a comprehensive view of material stocks, inflows and outflows connected to durable goods. Thus we note an annual per capitagrowth in Germanys anthropogenic material stock of 10 t. In the last 50 years an estimated 42 billion tons of material has been added to the anthropogenic stock. Not all of this can be classified to primary groups of goods. Around 28 million tons of material has been consumed by buildings, infrastructure, building services as well as durable consumer goods. Of this figure, over 99% can be located in the built environment. This mass is approximately 79 times larger than the material mass currently consumed every year by these sectors. Annual outflow from the stock is around 0.8%. The annual rate of growth of the observed stock of goods is 0.5%. The various figures can be further broken down according to individual groups of goods and material groups. This knowledge provides the necessary foundation for the long-term monitoring of the anthropogenic stock and, moreover, is an important step in the evidence-based development of a model to incorporate and to improve closed-loop material flows as well as to support politics of securing supply of raw materials.Quelle: http://www.sciencedirect.com
Blog post by Dagmer Dehmer 5 September 2017: Robert Habeck: A tremendous task! The visitors group including the Minister for the Environment of Schleswig-Holstein, Robert Habeck, and his fellow party members is standing at the 750 metres level of the Asse II mine, less than 100 metres away from the radioactive waste that was emplaced here until 1978. Annette Parlitz, public relations employee at the Asse-GmbH, turns her lamp upwards. Very clearly, the light shows deep cracks in the ceiling. At the 490 metres level, Ms. Parlitz had already shown the group bulges in the ground that are due to the pressure of the mountain that the mine is constantly exposed to. Every year the mine loses around 10,000 cubic metres of hollow space in total because of this deformation (convergence), says Ms. Parlitz. “We can really see that very vividly here”, confirms Mr. Habeck. “That is much more impressive than simply reading this type of information.” He is particularly fascinated by the devices for micro-acoustic measurements that register the crackling in the salt everywhere in the mine. This way, scientists know where stabilisation work might become necessary in the near future. A lot has changed compared with 2009, when the author of this post last visited the mine together with Sigmar Gabriel (SPD), the former Minister for the Environment. Everything seems to be tidier, more clearly structured and kept in a better condition. Robert Habeck shakes his head when he stands in front of the collecting basin at the 658 metres level below ground. The basin collects roughly 11,500 of the 12,500 litres of influent waters that infiltrate the mine every day. Anette Parlitz just tells us that another 1,000 litres of the brine are collected at levels further below. Another 20 litres are “in some ways” in contact with the radioactive waste every day. This contaminated brine is processed into contaminated concrete that remains in the mine, according to a special permission. The permission was given since the radionuclides contained in the concrete do not have long half-lives – which means that they are not particularly dangerous for the staff or the environment. In his introductory speech, Asse info centre manager Manuel Wilmanns had explained the results obtained from the comparison of different options (the final decision was taken in 2013 by adopting the “Lex Asse”): It is mainly due to the influent waters and their undetermined paths that scientists were unable to furnish sufficient proof for a safe close-down of the installation containing the radioactive waste. Experts do not know where the brine infiltrates the mine and they do not know what paths the waters follow below ground, either. It was observed, however, that heavy rainfall such as in the past few months does not affect the solution infiltrating the mine. Mr. Habeck was also told that the work associated with keeping the mine open and retrieving the waste produces costs of roughly 120 million euros per year. He asks if there is not a slight chance that the power companies could be charged with these costs, considering the fact that almost 70 percent of the waste is produced by nuclear power plants, as Manuel Wilmanns had said in his introductory speech. However, it is still the German state that must be blamed for the mistakes made with respect to the Asse mine. This fact cannot be argued away. This is one of these moments when Mr. Habeck becomes aware of the fact “what a tremendous task we face with respect to the disposal of this high-level radioactive waste.” At the end of his visit, he is impressed by the professional attitude of the Asse-GmbH staff and the atmosphere of open communication at the Asse info centre. This fact is also appreciated by the local party members. One of the visitors remembers quite clearly that more than ten years ago, the staff would not show him where the brine was collected in the mine. “That was kept secret.” Obviously, these times are over. Robert Habeck (on the right) at the main collection point on the 658 metres level Related Links Announcement - Asse II mine - 5 September 2017: Robert Habeck visits the Asse II mine Overview of all BGE blog posts
| Origin | Count |
|---|---|
| Bund | 344 |
| Land | 1 |
| Type | Count |
|---|---|
| Förderprogramm | 309 |
| Text | 21 |
| unbekannt | 14 |
| License | Count |
|---|---|
| geschlossen | 34 |
| offen | 309 |
| unbekannt | 1 |
| Language | Count |
|---|---|
| Deutsch | 313 |
| Englisch | 103 |
| Resource type | Count |
|---|---|
| Dokument | 2 |
| Keine | 274 |
| Webdienst | 1 |
| Webseite | 69 |
| Topic | Count |
|---|---|
| Boden | 297 |
| Lebewesen & Lebensräume | 288 |
| Luft | 229 |
| Mensch & Umwelt | 344 |
| Wasser | 344 |
| Weitere | 343 |