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Found 19 results.

B 1.2: Efficient water use in limestone areas - Phase 2

Das Projekt "B 1.2: Efficient water use in limestone areas - Phase 2" wird vom Umweltbundesamt gefördert und von Universität Hohenheim, Institut für Bodenkunde und Standortslehre durchgeführt. The elevated areas of Northern Thailand highlands are inhabited by ethnic minorities. On the other hand, the Thai majority prefers the valley bottoms. Population growth of all groups, reforestation and commercialisation of agriculture lead to an increasing pressure on land and water resources. Therefore, intensified land and water use systems are desired which are resource conserving at the same time. Here, special problem areas are the karstic limestone catchments due to the limited of surface waters.Own pre-investigations together with subproject A1 have shown, that land use systems there are subsistence oriented and local farmers do not use irrigation. But they would like to develop such technology, especially in order to increase staple crop production (highland rice, maize). But lack of irrigation possibilities is also responsible for the lack of diversification of land use systems with respect to orchards. One possibility to increase staple crop yields is to prolong the vegetation period by use of water harvesting technologies. Aim of this project is to develop such low cost water harvesting technologies (together with subproject B3.1) based on a participatory approach and to model the effect of these on the water balance at the catchments scale. This will be done on the basis of the previous variability studies and should lead to model tools, which allow to evaluate ex ante SFB innovation effects on the water balance. The project area is the Bor Krai catchments. Here, weirs will be installed to quantify surface water availability. An investigation plot will be situated near the village of Bor Krai which serves for water balance measurements (TDR/densitometry) and at the same time as demonstration plot for the local community. Here water harvesting by means of filling the soils field capacity at the end of the rainy season by gravity irrigation in order to prolong the vegetation period will be researched. Through cropping of participatory evaluated varieties the crop yield should be increased. The water consumption of traditionally managed and dominant crops (including orchards) will be measured at three further sites in the catchment (TDR, tensiometer). The water balance of the soil cover in the karst catchment will be based on the coupling of a SOTER map with a water transport model. The data base will be completed by soil type mapping, spatially randomised collection of soil physical properties (texture, bulk density, infiltration, water retention curve) and determination of the ku-function at two representative sites. As project results the available water amount for irrigation purposes will be quantified. The effective use of this water reserve will lead to increased productivity of the dominant crops and limitations to orchard productivity will be reduced. (abridged text)

Sub project:The effect of iron(III)-sulfide interactions on electron transfer processes in anoxic aquifers

Das Projekt "Sub project:The effect of iron(III)-sulfide interactions on electron transfer processes in anoxic aquifers" wird vom Umweltbundesamt gefördert und von Universität Bayreuth, Fachgruppe Geowissenschaften, Bayreuther Zentrum für Ökologie und Umweltforschung (BayCEER), Lehrstuhl für Hydrologie durchgeführt. Strong evidence exists that the oxidation of H2S by ferric (oxyhydr)oxides occurs also in ground water systems and may exert a major role for the sulphur and iron cycle and in particular for the electron and carbon flow in aquifers. To date, no systematic study has been performed that allows to quantitatively assess its significance in such systems. This project aims to fill this gap of knowledge. The extent of the reaction depends on mineral reactivity, which we hypothesize can be expressed in terms of a generalized kinetic model for the full pH range of environmental relvance. This model accounts for the adsorption of H2S at lower pH values and of HS- at circumneutral pH to the neutral ferric (oxyhydr)oxide surface to form the reactive species FeSH. Variations in reactivity may be caused by intrinsic factors such as surface acidity of the iron mineral and solution composition, such as ionic strength and competition with other ions. The overall goals of this project therefore are to demonstrate the validity of this approach in order to quantify the kinetics for abiotic anaerobic H2S oxidation by ferric (oxyhydr)oxides, and to elucidate the role of this process as a precursor reaction for further microbial transformation of sulphur species in the aquifer.

Towards improved properties of biodegradable polymers made from Sugar Cane, PLA

Das Projekt "Towards improved properties of biodegradable polymers made from Sugar Cane, PLA" wird vom Umweltbundesamt gefördert und von Universität Halle-Wittenberg, Institut für Physik durchgeführt. In daily life, construction polymers play an important role. Most of products are not reusable for different reasons (cost, hygiene, ) so the need of an environment saving production and disposal is evident. To besides from the obvious task on saving resources and environment, there is also a growing economical interest in this issue. On of the most promising candidates for a thermoplastic construction polymer that can be manufactured from bio-renewable resources and is biodegradable is Polylactic acid (PLA), for which Corn starch (in the U.S.) or sugarcanes (rest of world) are the common feedstock. Polylactic acid can be processed like most thermoplastics into fiber (for example using conventional melt spinning processes) and film. However, the low glass transition temperature prohibits many applications, like usage for coffee cups that will simply soften and flow away upon filling with hot drinks. One popular option to cope with this is the modification with other polymers, either conventional product or even enantiomers of PLA itself. For example, the melting temperature can be increased 40-50 C and the Heat Deflection temperature of PLLA can be increased from approximately 60 C to up to 190 C for by physically blending the polymer with PDLA (poly-D-lactide). PDLA and PLLA are known to form a highly regular stereocomplex with increased crystallinity. The maximum effect in temperature stability is achieved when a 50-50 blend is used, but even at lower concentrations of 3-10Prozent of PDLA a substantial effect is achieved. In the latter case PDLA is used as a nucleating agent, thereby increasing the crystallization rate. Due to the higher crystallinity of this stereo-complex, the biodegradability will become slower. The interesting feature is that the polymer blend remains transparent, which is one to the desirable properties that must be kept upon modification.

3R-Studie - Reduce, Reuse, Recycle für die G8-Staaten

Das Projekt "3R-Studie - Reduce, Reuse, Recycle für die G8-Staaten" wird vom Umweltbundesamt gefördert und von bifa Umweltinstitut GmbH durchgeführt. bifa hat ein Vorhaben für die G8- Staaten bearbeitet, in dem die Entwicklungen in Deutschland innerhalb der neun Handlungsfelder ( Actions ) des Kobe 3R Action Plan dargestellt werden. Mit der 3R-Initiative beabsichtigen die G8-Staaten seit 2004 eine bessere Verankerung der Nachhaltigkeit im Umgang mit Rohstoffen durch die stärkere Förderung der drei Prinzipien Reduce, Reuse, Recycle , abgekürzt 3R , in den nationalen Abfallwirtschaftspolitiken. Im Rahmen der Beauftragung untersuchte bifa, welche Punkte aus dem Kobe 3R Action Plan bereits hinreichend durch bestehende Entwicklungen bzw. ergriffene Maßnahmen abgedeckt sind, bei welchen Aktionen noch Lücken bestehen und wie diese Lücken gefüllt werden können. Legt man die drei Zielsetzungen des Kobe 3R Action Plan und die ihnen zugeordneten Handlungsfelder als Prüfraster über die deutsche Abfallwirtschaftspolitik, lässt sich ein sehr hoher Erfüllungsgrad feststellen. Ein erheblicher Teil der vorgeschlagenen Handlungsoptionen war in Deutschland bereits vor 2008 durch konkrete Maßnahmen umgesetzt worden. Für einen anderen Teil wiederum lässt sich der Ursprung, z. B. in Form eines ersten Gesetzentwurfs, auf die Zeit vor 2008 zurückdatieren, die Umsetzung durch die Veröffentlichung im Bundesgesetzblatt aber fand 2008-2011 statt. Einige Regelungen setzen Richtlinien oder Verordnungen der EU, die ihrerseits zum Teil auf Bestrebungen Deutschlands hin zustande kamen, in nationales Recht um. Mit dem in einer fortgeschrittenen Version vorliegenden Entwurf eines novellierten Kreislaufwirtschaftsgesetzes vollzieht Deutschland einen weiteren wichtigen Schritt hin zu einer Abfallwirtschaft, deren Markenzeichen insbesondere eine hohe Ressourceneffizienz ist. Dennoch verbleiben Optimierungspotenziale, zu deren Ausschöpfung bifa Vorschläge für das Bundesumweltministerium erarbeitet hat. Im Zuge des Projekts analysierte bifa u. a. die Importe und Exporte notifizierungspflichtiger Abfälle. Der Saldo hat sich den bifa-Analysen zufolge seit 1998 umgekehrt: Wurden 1998 noch etwa doppelt so viel notifizierungspflichtige Abfälle exportiert wie importiert, hat sich der Import seitdem vervierfacht und die Exporte sind sogar leicht gesunken. Ein wichtiger Grund ist die Verfügbarkeit von Behandlungs- und Verwertungskapazitäten von hoher Leistungsfähigkeit in Deutschland. Die Schadstoffentfrachtung von Abfällen aus Ländern mit einer wenig entwickelten Entsorgungsinfrastruktur führt jedoch innerhalb der deutschen Öffentlichkeit immer wieder zu Kontroversen. Methoden: Analyse und Moderation sozialer Prozesse.

Soil colour spectra of prehistoric pit fillings as a new analytical tool to measure changing soil characteristics over time on a regional scale

Das Projekt "Soil colour spectra of prehistoric pit fillings as a new analytical tool to measure changing soil characteristics over time on a regional scale" wird vom Umweltbundesamt gefördert und von Rheinische Friedrich-Wilhelms-Universität Bonn, Institut für Nutzpflanzenwissenschaften und Ressourcenschutz (INRES), Bereich Bodenwissenschaften, Allgemeine Bodenkunde und Bodenökologie durchgeführt. Prehistoric pits are filled with ancient topsoil material, which has been preserved there over millennia. A characteristic of these pit fillings is that their colour is different depending on the time the soil material was relocated. Soil colour is the result of soil forming processes and soil properties, and it could therefore indicate the soil characteristics present during that specific period. To the best of our knowledge, no investigation analysed and explained the reasons for these soil colour changes over time. The proposed project will investigate soil parameters from pit fillings of different archaeological periods in the loess area of the Lower Rhine Basin (NW-Germany). It aims to implement the measurement of colour spectra as a novel analytical tool for the rapid analyses of a high number of soil samples: the main goal is to relate highresolution colour data measured by a spectrophotometer to soil parameters that were analysed by conventional pedogenic methods and by mid infrared spectroscopy (MIRS), with a main focus on charred organic matter (BPCAs). This tool would enable us to quantify the variation of soil properties over a timescale of several millennia, during different prehistoric periods at regional scale and for loess soils in general. Detailed information concerning changing soil properties on a regional scale is necessary to determine past soil quality and it helps to increase our understanding of prehistoric soil cultivation practices. Furthermore, these information could also help to increase our understanding about agricultural systems in different archaeological periods.

Model coupling and complex structures - Evaporation-driven transport and precipitation of salts in porous media

Das Projekt "Model coupling and complex structures - Evaporation-driven transport and precipitation of salts in porous media" wird vom Umweltbundesamt gefördert und von Universität Stuttgart, Institut für Wasser- und Umweltsystemmodellierung durchgeführt. Degradation of the soil productivity due to salt accumulation (salinization) is a major concern in arid, semi-arid and coastal regions. Soil salinization is an old issue but encouraged irrigation practices have been rapidly increasing its intensity and magnitude in the past few decades. Studies have shown that excess of the irrigated water contributes significantly to evaporation from the bare soil surface and therefore to the salinization. In some parts of the world soil salinity has grown so acute that the agricultural lands have been abandoned. Evaporation salinization is mainly influenced by interaction between the flow and transport processes in the atmosphere and the porous-medium. On the atmosphere side, wind velocity, air temperature and radiation have a strong impact on evaporation. Furthermore, turbulence causes air mixing, influences the vapor transport and creates a boundary layer at the soil-atmosphere interface which indeed influences evaporation. On the porous-medium side, dissolved salt is transported under the influence of viscous forces, capillary forces, gravitational forces and advective and diffusive fluxes. The water either directly evaporates from the water-filled pores or it is transported to air due to diffusive processes. Continuous evaporation promotes salt accumulation and precipitation resulting in soil salinization. In the scope of this work we attempt to develop a model concept capable of handling flow, transport and precipitation processes related to evaporative salinization of an unsaturated porous-medium.

Ground-truthing magnetic recording in meteorites

Das Projekt "Ground-truthing magnetic recording in meteorites" wird vom Umweltbundesamt gefördert und von Ludwig-Maximilians-Universität München, Department für Geo- und Umweltwissenschaften, Sektion Geophysik durchgeführt. Whether primordial bodies in the solar system possessed internally-generated dynamos is a fundamental constraint to understand the dynamics and timing of early planetary formation. Paleointensity studies on several meteorites reveal that their host planets possessed magnetic fields within an order-of magnitude of the present Earths field. Interpretation of paleointensity data relies heavily on fundamental knowledge of the magnetic properties of the magnetic carriers, such as the single to multidomain size threshold or how the saturation magnetization varies as a function of grain size, yet very little knowledge exists about these key parameters for some of the main magnetic recorders in meteorites: the iron-nickel alloys. Moreover, most meteorites have experienced some amount of shock during their histories, yet the consequence of even very small stresses on paleointensity data is poorly known.We wish to fill these gaps by magnetically characterizing Fe-Ni alloys as a function of grain size and by determining how absolute and relative paleointensity data are biased by strain levels lower than those petrologically observable (less than 4-5 GPa). For example, our preliminary work shows that an imposed stress of 0.6 GPa will reduce absolute paleointensity estimates by 46Prozent for single domain magnetite-bearing rocks. In general, paleointensity determinations possess inherent disadvantages regarding measurement precision and the inordinate amount of human time investment. We intend to overcome these limitations by extending and improving our fully automated magnetic workstation known as the SushiBar.

IWaTec - Integrated Water Technologies

Das Projekt "IWaTec - Integrated Water Technologies" wird vom Umweltbundesamt gefördert und von Universität Duisburg-Essen, Zentrum für Wasser- und Umweltforschung durchgeführt. Egypt passed a revolution and changed its political system, but many problems are still lacking a solution. Especially in the field of water the North African country has to face many challenges. Most urgent are strategies to manage the limited water resources. About 80% of the available water resources are consumed for agriculture and the rest are for domestic and industrial activities. The management of these resources is inefficient and a huge amount of fresh water is discarded. The shortage of water supply will definitely influence the economic and cultural development of Egypt. In 2010, Egypt was ranked number 8 out of 165 nations reviewed in the so-called Water Security Risk Index published by Maplecroft. The ranking of each country in the index depends mainly on four key factors, i.e. access to improved drinking water and sanitation, the availability of renewable water and the reliance on external supplies, the relationship between available water and supply demands, and the water dependency of each countrys economy. Based on this study, the situation of water in Egypt was identified as extremely risky. A number of programs and developed strategies aiming to efficiently manage the usage of water resources have been carried out in the last few years by the Egyptian Government. But all these activities, however, require the availability of trained and well-educated individuals in water technology fields. Unfortunately, the number of water science graduates are decreasing and also there are few teaching and training courses for water science offered in Egypt. However, there is still a demand for several well-structured and international programs to fill the gap and provide the Egyptian fresh graduates with the adequate and up-to-date theoretical and practical knowledge available for water technology. IWaTec is designed to fill parts of this gap.

Dichtigkeit von Lagerstätten-Deckschichten Untertage bezüglich CO2-Speicherung

Das Projekt "Dichtigkeit von Lagerstätten-Deckschichten Untertage bezüglich CO2-Speicherung" wird vom Umweltbundesamt gefördert und von RWTH Aachen University, Lehrstuhl für Applied Geophysics and Geothermal Energy, E.ON Energy Research Center (ERC) durchgeführt. Geological storage involves injecting CO2 directly into underground geological formations. CO2 has been used for decades in oil industry to increase recovery (Figure 1). Saline aquifers (Figure 2)have also been suggested as CO2 storage sites. Prevention of post sequestration leakage to the surface from deep saline aquifers is one the key issues in disposal of CO2 into the aquifer. The permanence of the sequestration of CO2 into the saline aquifer depends strongly on the integrity of the top sealing formation over geological time (from one hundred to several thousand years depending on the size). In order to assess whether the stored CO2 retains in the formation or not, the resistivity of the cap rock against the geochemical alteration or geomechanical deformation should be examined. Numerical Simulation: This multidisciplinary project is aimed to better quantify the long-term integrity of the cap rock based on the laboratory experiments. In order to characterize the reservoir, laboratory experiments will be conducted on the selected rocks form the North Rhine-Westphalia (Germany) region including petrophysical tests. In this study, the experimental results and the geologic data of the Bunter sandstone and Rotliegend sandstone formations will be used in geological model. Using ECLIPSE commercial simulator enables us to fill the gap between theoretical analysis and laboratory experiments. Several injection scenarios will be performed to study the multi-component behavior of the multi-phase flow in porous media as well as geochemical alteration and geomechanical deformation of the cap rock. We will also introduce the transport phenomena (heat and mass transfer) of CO2 by using SHEMAT and TOUGHREACT simulators. Finally we will look for a solution to link these three simulators to have the best leakage risk assessment. This project is funded by the West LB foundation 'Future of North Rhine-Westphalia.

Monitoring of Water Content Distributions inside a Lysimeter with GPR-Tomography

Das Projekt "Monitoring of Water Content Distributions inside a Lysimeter with GPR-Tomography" wird vom Umweltbundesamt gefördert und von Technische Universität Berlin, Institut für Angewandte Geowissenschaften, Fachgebiet Angewandte Geophysik (mit Schwerpunkt Umwelt- und Ingenieurgeophysik) durchgeführt. A lysimeter is a vessel containing soil placed with its top edge to the ground surface. Lysimeter are used to study phases of the hydrological cycle in terms of water content and dynamics, e.g. infiltration, evapotranspiration or runoff. Lysimeter provide a good alternative to carry out and test various methods or theoretical theories under relative undisturbed circumstances. In cooperation with the Institute of Chemistry and Dynamics of the Geosphere, IV Agrosphere (ICG-IV) of the Forschungszentrum Jülich GmbH, the solute transport inside a lysimeter ought to be investigated.To avoid the inevitable problem of the boundary conditions for electromagnetic geophysical methods of a normal lysimeter with its metal wall, an alternative had to be found. Therefore PVC-cylinders were chosen with 1.5 m height and 1.2 m diameter. The dielectric permittivity of soils depends strongly on the water content. Therefore, GPR was used as it can provide non-invasive high-resolution information regarding the distribution of the dielectric permittivity of a heterogeneous medium. Because the used lysimeter has PVC walls tomographic measurements can be performed. Considering the relatively small dimensions of the lysimeter (1.2m diameter, 1.5m height) and the armament with sensors for other methods, a pair of shielded antennas was chosen with centre frequencies of approx. 750 MHz. In April and September 2002 first measurements were carried out on a filled but unequipped lysimeter to check signal quality, feasibility as well as the needed time to gather a dataset under ideal conditions. Furthermore pot irrigation tests were made in 2002 and 2004 to estimate the actual resolution with the available equipment. To derive the volumetric water content, the calculated dielectric permittivity values have to be transformed. Based on the soil inside the lysimeter (approx. 80% sand, 15% silt and 5% clay with approx. 40% porosity) appropriate mixing formulas for bulk dielectric permittivity have to be chosen and compared to the results gathered from alternative methods.

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