Arsenic-contaminated ground- and drinking water is a global environmental problem with about 1-2Prozent of the world's population being affected. The upper drinking water limit for arsenic (10 Micro g/l) recommended by the WHO is often exceeded, even in industrial nations in Europe and the USA. Chronic intake of arsenic causes severe health problems like skin diseases (e.g. blackfoot disease) and cancer. In addition to drinking water, seafood and rice are the main reservoirs for arsenic uptake. Arsenic is oftentimes of geogenic origin and in the environment it is mainly bound to iron(III) minerals. Iron(III)-reducing bacteria are able to dissolve these iron minerals and therefore release the arsenic to the environment. In turn, iron(II)-oxidizing bacteria have the potential to co-precipitate or sorb arsenic during iron(II)- oxidation at neutral pH followed by iron(III) mineral precipitation. This process may reduce arsenic concentrations in the environment drastically, lowering the potential risk for humans dramatically.The main goal of this study therefore is to quantify, identify and isolate anaerobic and aerobic Fe(II)-oxidizing microorganisms in arsenic-containing paddy soil. The co-precipitation and thus removal of arsenic by iron mineral producing bacteria will be determined in batch and microcosm experiments. Finally the influence of rhizosphere redox status on microbial Fe oxidation and arsenic uptake into rice plants will be evaluated in microcosm experiments. The long-term goal of this research is to better understand arsenic-co-precipitation and thus arsenic-immobilization by iron(II)-oxidizing bacteria in rice paddy soil. Potentially these results can lead to an improvement of living conditions in affected countries, e.g. in China or Bangladesh.
Groundwater contamination by organic compounds represents a widespread environmental problem. The heterogeneity of geological formations and the complexity of physical and biogeochemical subsurface processes, often hamper a quantitative characterization of contaminated aquifers. Compound specific stable isotope analysis (CSIA) has emerged as a novel approach to investigate contaminant transformation and to relate contaminant sources to downgradient contamination. This method generally assumes that only (bio)chemical transformations are associated with isotope effects. However, recent studies have revealed isotope fractionation of organic contaminants by physical processes, therefore pointing to the need of further research to determine the influence of both transport and reactive processes on the observed overall isotope fractionation. While the effect of gasphase diffusion on isotope ratios has been studied in detail, possible effects of aqueous phase diffusion and dispersion have received little attention so far.The goals of this study are to quantify carbon (13C/12C) and, for chlorinated compounds, chlorine (37Cl/35Cl) isotope fractionation during diffusive/dispersive transport of organic contaminants in groundwater and to determine its consequences for source allocation and assessment of reactive processes using isotopes. The proposed research is based on the combination of high-resolution experimental studies, both at the laboratory (i.e. zero-, one- and two-dimensional systems) and at the field scales, and solute transport modeling. The project combines the expertise in the field of contaminant transport with the expertise on isotope methods in contaminant hydrogeology.
Honey is among the oldest food products of mankind and beekeeping is deeply rooted in every European culture. Numerous European and national regulations control honey quality, which reflects both the high nutritional and societal value of the product. Yet in an environment with increasing chemical pollution and the wide use of agrochemicals, honey runs high risks of becoming chemically polluted. In addition a broad spectrum of chemicals is used to treat honeybee diseases, further contaminating honey with sometimes highly toxic compounds. The BEE SHOP is a network of ten leading European honeybee research groups in honey quality, pathology, genetics and behaviour as well as selected beekeeping industries, which all share a common interest in promoting Europe's high honey quality standards. The prime goal is to reduce potential sources of honey contamination due to both foraging contaminated nectar and chemotherapy of honeybee diseases. The BEE SHOP will therefore deal with the development of biological resistance to pests and pathogens to avoid chemotherapy. Various European honeybee races and populations will be screened for their disease resistance potential to the main pressing pathogens. Differences in foraging patterns among European honeybees and their underlying mechanisms will be studied to identify behavioural traits reducing contamination. Differences in disease susceptibility will be genetically analysed by QTL mapping. Major loci in the genome will be identified with the aid of the published honeybee genome. SNPs will be developed to allow for selection of specific target genes in both drones and queens before insemination. This will greatly accelerate the selection progress in honeybee breeding allowing for the swift establishment of resistant but efficient stock. New tools for testing honey quality and authenticity will be developed to allow inspections of honey according to the current EC directives on honey quality and organic beekeeping.
Background: Low Emission Zones (LEZs) are areas or roads where the most polluting vehicles are restricted from entering. The effectiveness of LEZs to lower ambient exposures is under debate. This study focused on LEZs that restricted cars of Euro 1 standard without appropriate retrofitting systems from entering and estimated LEZ effects on NO2, NO, and NOx (=NO2+NO) concentrations. Methods: Continuous half-hour and diffuse sampler 4-week average NO2, NO, and NOx concentrations measured inside and outside LEZs in 17 German cities of 6 federal states (2005-2009) were analysed as matched quadruplets (two pairs of simultaneously measured index values inside LEZ and reference values outside LEZ, one pair measured before and one after introducing LEZs with time differences that equal multiples of 364 days) by multiple linear and log-linear fixed-effects regression modelling (covariables: e.g., wind velocity, amount of precipitation, height of inversion base, school holidays, truck-free periods). Additionally, the continuous half-hour data was collapsed into 4-week averages and pooled with the diffuse sampler data to perform joint analysis. Results: More than 3,000,000 quadruplets of continuous measurements (half-hour averages) were identified at 38 index and 45 reference stations. Pooling with diffuse sampler data from 15 index and 10 reference stations lead to more than 4,000 quadruplets for joint analyses of 4-week averages. Mean LEZ effects on NO2, NO, and NOx concentrations (reductions) were estimated to be at most - 2 microgram/m3 (or - 4 percent). The 4-week averages of NO2 concentrations at index stations after LEZ introduction were 55 microgram/m3 (median and mean values) or 82 microgram/m3 (95th percentile). Conclusion: This is the first study investigating comprehensively the effectiveness of LEZs to reduce NO2, NO, and NOx concentrations controlling for most relevant potential confounders. Our analyses indicate that there is a significant, but rather small reduction of NO2, NO, and NOx concentrations associated with LEZs. Key words: air quality, low emission zone, NO2, NO and NOx, air pollution
Objective: Space heating accounts for more than 50Prozent of the energy consumption of public & residential buildings, and reduction of this energy demand is a key strategy in the move to low energy/low carbon buildings. The careful management of air flow within a building forms part of this strategy through the control of inlet fresh air and exhaust air, maximising air re-circulation, and minimising the amount of fresh air which is often drawn in through a heat exchanger. However, there is a high risk that the air quality is reduced. Continued exposure to environments with poor air quality is a major public health concern in developed and developing countries. It is estimated that the pollutants responsible for poor air quality cause nearly 2.5 million premature deaths per year world-wide. Significantly, around 1.5 million of these deaths are due to polluted indoor air, and it is suggested that poor indoor air quality may pose a significant health risk to more than half of the world's population. Perhaps surprisingly, remedial action to improve air quality is often easy to implement. Relatively simple measures such as increased air flow through ventilation systems, or a greater proportion of fresh air to re-circulating air are sufficient to improve air quality. Low-energy air purification and detoxification technologies are available which will reduce the concentration of specific pollutants. Similarly, filtration systems (e.g. electrostatic filters) can be switched in to reduce the level of the particulate matter in the air (the principle pollutant responsible for poor health). The INTASENSE concept is to integrate a number of micro- and nano-sensing technologies onto a common detection platform with shared air-handling and pre-conditioning infrastructure to produce a low-cost miniaturised system that can comprehensively measure air quality, and identify the nature and form of pollutants. INTASENSE is a 3-year project which brings together 8 organisations from 5 countries.
Antimony (Sb) is a rather rare element in the earth's crust, but in the recent past, human activities have led to highly elevated Sb concentrations in soils and sediments at many locations and, as a consequence, to increased exposure of biota to this toxic element. Soil contamination by Sb has recently become an urgent issue in particular on shooting ranges. In Switzerland, all shooting ranges are currently examined and will be remediated within the next decade. This implies the removal of large quantities of contaminated soil. Large fractions of these soils are not heavily contaminated but have to be treated because they are located in pollution-sensitive areas such as groundwater protection zones. This soil can potentially be reused for less sensitive types of land-use, saving high treatment costs and precious hazardous waste disposal space. Knowledge about the risks of Sb leaching from such soils is very limited, however. One key factor regarding solute leaching is the water regime, particularly in soils subject to permanent or periodic water-logging. Water-logging strongly inhibits soil aeration, and this can have a strong influence on the entirety of chemical and biological conditions affecting solute transport in soil. This holds all the more for elements that are sensitive to changes in their oxidation state under environmental conditions such as Sb. Given that there is very little information available on the transport behavior of Sb in soils, particularly under dynamic water regimes, this project has the aim to investigate the influence of water-logging on Sb leaching from contaminated soil. For this purpose, we carry out experiments with a relocated shooting range soil as well as with a comparable synthetic soil in order to identify and model the role of sorption and redox processes on Sb mobilization and leaching. Special attention will be given to the speciation of Sb in the soil solution. The results will be relevant beyond providing a scientific basis for the risk assessment of Sb leaching from contaminated soil, as it will also further the mechanistic understanding of how water-logging affects the transport of redox-sensitive solutes in soils in general.
Due to the tendency to bioaccumulate, trace concentrations of selenium in fresh waters have led to disastrous toxicity effects on water birds and fish in the past. Although this adverse impact was first noticed in the early 1980s, to date no sustainable solution has been found for the remediation of selenium contaminated drainage and waste waters. Compared to water soluble forms, elemental selenium is considered less toxic. Therefore, various remediation approaches try to use microorganisms that are highly efficient in reducing selenium oxyanion concentrations by formation of insoluble elemental selenium. Such biogenic elemental selenium, however, does not crystallize to large particles and remains dispersed in solution as a colloidal suspension, thus being subject to re-oxidation, uptake and assimilation by biota. The probable reason for the tendency of biogenic selenium to remain in solution suspended as nanoparticles is an organic polymer layer modifying the surface, preventing crystallization and conferring the selenium core with physico-chemical properties different from particles without such a layer. To date, it is not known, which molecules (proteins, (poly)saccharides, etc.) form this organic polymer layer. Consequently, it is furthermore unknown, if all microbial groups mediating selenium reduction (either via a respiratory or via co-metabolic reduction) produce the same organic polymer layer around the selenium core. The physico-chemical properties of the layer, however, will strongly influence sedimentation and transport processes of selenium in the environment. Due to the complex chemistry and the nanocrystalline character of the selenium particles, uncertainties persist concerning the selenium solid phase, which is formed biogenically. It is not known, if and to which extent selenium that bears such a polymers layer is subject to further biotic and abiotic oxidation and reduction processes, although these processes will largely govern the ecotoxicological effects of selenium. The present project aims at filling the gaps in understanding biogenic selenium formation by systematically investigating the morphology and speciation of the solid phase and the surface modification mechanisms. By direct (spectroscopic) methods we will determine selenium solid phase speciation and its transformations under environmental conditions. We will develop methods allowing the identification of the organic polymer layers modifying selenium nanoparticles by different microbial groups. Thus we will be able to deliver a mechanistic model describing both layer and core of biogenic selenium nanoparticles and the possible impact(s) they have on each other.
Although the use of genetically modified plants for bioremediation, or the in situ cleaning of contaminated sites, has been known for quite some time, little attention has so far been paid to the production of antibodies in plants and their ex vivo application in selective depletion. Therefore, highly affine and specific antibodies against algal toxins using microcystin as an example will be produced in plants at low cost within this research project. The basis is a monoclonal antibody (Mab 10E7, species: mouse) generated in a former research project. The sequence of the variable domains will be determined, optimized for plants and sub cloned into suitable plant transformation vectors, which already contain constant antibody sequences. In addition, a scFv fragment containing different tag sequences and fusion proteins will be constructed. Leaf-based (tobacco) as well as seed-based (barley) systems will be used.Affinity-purified plant-produced antibodies (plantibodies) will be characterized in detail for their binding properties using microtitre plate-ELISA and surface plasmon resonance (SPR). The monoclonal mouse antibody will be used as reference. To assure cost-efficiency for future applications, roughly purified fractions (sequential pH and temperature treatment followed by filtration) will be tested for the upscaling. Following immobilization of the plantibody fractions on suitable substrates, for instance membranes, porous polymer monoliths or in porous glasses, their application for depletion will be defined using model water samples spiked fortified with microcystins.
The proposed project is the follow-up project of our present SNF-project CAPAC (Climate And Pol-lution Analysis of Cairo) phase one. Its main purpose is the finishing of the work begun in phase one in terms of methodology and data analysis. CAPAC is conducted by a doctorand, Miss Corinne Frey. CAPAC aims to combine in situ measurements of the energy balance with remote sensing tech-niques to parameterise urban and non-urban heat fluxes of the mega-city Cairo, Egypt and its surroundings. Cairo is located within a green north-south oriented strip of agricultural land and on the other hand between two desserts in the west and east. This makes the location of Cairo unique and very interesting for an urban climate study like this. Scientific objectives are the computation of very high resolution radiation and heat fluxes in urban areas under the conditions of spatial homogeneity/ heterogeneity of urban land cover. Very interesting is the analysis of how urban greens influence the urban heat fluxes and how the new suburbs of Cairo, which are expanding into the dessert explosively, will modify the local climate. The population of Cairo is growing several hundred thousand people per year. During the first phase of CAPAC a field campaign was conducted in Cairo. This data serve as calibration and validation of the remote sensing analysis. Following this campaign, algorithm development and data analysis will be the main task of the following months. This includes the analysis of the in situ measured flux data, as well as the evaluation of the estimated radiation and energy balance terms using ASTER and LANDSAT remotely sensed data. Main tasks in the determination of the radiation and energy balance terms using satellite data will be (1) the completion of the haze-removal-algorithm for the haze contaminated scenes, (2) the completion of the algorithm for estimation of the aerosol optical depth from satellite data and (3) to improve the S-Sebi method for the estimation of the Bowen-ratio or to find a better suited method for the estimation of heat fluxes. Another task, which is primarily related to quality control is the determination of the Bi-directional reflectance function (BRF) over Cairo using satellite data from CHRIS/PROBA, which are already acquired by the European Space Agency (ESA) on our demand. To substantiate the findings from Cairo another area of interest was chosen, namely Beer Sheva, Israel. Beer Sheva is located in the middle of the desert, offering a pure desert climate. There a small follow-up field campaign is planed together with Dr. Oded Potcher from Ben Gurion University in Beer Sheva.
| Origin | Count |
|---|---|
| Bund | 36 |
| Type | Count |
|---|---|
| Förderprogramm | 36 |
| License | Count |
|---|---|
| offen | 36 |
| Language | Count |
|---|---|
| Deutsch | 5 |
| Englisch | 34 |
| Resource type | Count |
|---|---|
| Keine | 29 |
| Webseite | 7 |
| Topic | Count |
|---|---|
| Boden | 36 |
| Lebewesen und Lebensräume | 36 |
| Luft | 36 |
| Mensch und Umwelt | 36 |
| Wasser | 36 |
| Weitere | 36 |