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.
Present concepts of industrial management are based on a linear value chain of products and services. Input materials such as raw materials, water and energy are transformed into products and by-products but cogenerating significant amount of wastes and polluting emissions. Cleaner production approach, focusing on single process efficiency within companies, and industrial symbiosis approach, focusing on systemic spatial resource efficiency among different companies, are both contributing to reduce the environmental impact of the industrial production. In this context, different tools to optimize industrial management have been developed, but none of them include both approaches. The aim of the present project is to combine both approaches in order to increase the overall resource efficiency of industrial processes within a system of different factories. Overall goal of the program Ecomanindustry: Development of a universal reproducible software based tool called CPIS for decision support integrating the existing experiences and methodologies of Cleaner Production (CP) and Industrial Symbiosis (IS). The CPIS-tool will facilitate inter-industrial assessment and communication for waste avoidance and reuse of materials based on the Software as a Service (SaaS) principles. Specific goals of the swiss partners: FHNW: FHNW will be the coordinator of the overall Project and lead field tests and case studies. FHNW will collect customer feedback on existing software and test user friendly and failure free functionality of a beta version of the developed CPIS-tool in a field test, and proof customer acceptance of the CPIS-tool application in two case studies. UNIL: UNIL will gather and valorize previous research and experiences of existing GIS-based decision support tools for the development of eco-industrial parks, design the concept, functionalities and boundaries of the software-based CPIS-tool, and choose the appropriate technologies to be implemented in the CPIS-tool. SOFIES: SOFIES will build a community of users and service provider, ensure the long term development of the CPIS-tool, promote the dissemination to other countries and elaborate adequate user guide and training to facilitate dissemination.
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.
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.
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.
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.
Understanding transport of contaminants is fundamental for the management of groundwater re-sources and the implementation of remedial strategies. In particular, mixing processes in saturated porous media play a pivotal role in determining the fate and transport of chemicals released in the subsurface. In fact, many abiotic and biological reactions in contaminated aquifers are limited by the availability of reaction partners. Under steady-state flow and transport conditions, dissolved reactants come into contact only through transverse mixing. In homogeneous porous media, transverse mixing is determined by diffusion and pore-scale dispersion, while in heterogeneous formations these local mixing processes are enhanced. Recent studies investigated the enhancement of transverse mixing due to the presence of heterogeneities in two-dimensional systems. Here, mixing enhancement can solely be attributed to flow focusing within high-permeability inclusions. In the proposed work, we will investigate mixing processes in three dimensions using high-resolution laboratory bench-scale experiments and advanced modeling techniques. The objective of the proposed research is to quantitatively assess how 3-D heterogeneity and anisotropy of hydraulic conductivity affect mixing processes via (i) flow focusing and de-focusing, (ii) increase of the plume surface, (iii) twisting and intertwining of streamlines and (iv) compound-specific diffusive/dispersive properties of the solute species undergoing transport. The results of the experimental and modeling investigation will allow us to identify effective large-scale parameters useful for a correct description of conservative and reactive mixing at field scales allowing to explain discrepancies between field observations, bench-scale experiments and current stochastic theory.
Arsenic-contaminated ground- and drinking water is a global environmental problem with about 1-2Prozent of the worlds population being affected. The upper drinking water limit for arsenic (10 ìg/L) is often exceeded, especially in Asian countries, such as Vietnam. Household sand filters are already used as one very simple and cost-efficient treatment to remove arsenic from water. Oxidation of dissolved iron (Fe(II)) present in the groundwater leads to the formation of sparsely soluble iron(hydr)oxide particles (Fe(III)OOH) in the sand filter, which bind negatively charged arsenic species and reduce arsenic concentrations in the water. Arsenite (As(III); H3AsO3) binds generally less strong to metal oxides than arsenate (As(V); H2AsO4 -/HAsO4 2-), therefore As(V) is removed much more effectively than As(III). This is why As(III) oxidation to As(V) is of special interest for arsenic removal from drinking water. Whether and how the activity of iron- and arsenite-oxidizing bacteria contributes to effective arsenic removal in household sand filters is currently not known. One of the goals of this study therefore is to isolate, identify, and quantify Fe(II)- and As(III)-oxidizing microorganisms from filters and to study their iron and arsenic redox activities. Cultivation-based work will be complemented by molecular, cultivation-independent techniques to characterize and quantify the microbial communities in samples from different filter locations taken at various time points during filter operation (both at field sites and in artificial laboratory filter systems). The isolated iron- and arsenite-oxidizing bacteria will be studied with respect to their abilities to precipitate iron minerals (in the presence or absence of arsenic) and oxidize arsenite. Biogenic and abiogenic iron minerals formed by the isolated strains in the lab, on the sand filter material in Vietnam and in artificial laboratory filter systems will be identified and characterized, also with respect to arsenic sorption. And we will determine how biotic and abiotic processes that contribute to arsenic mobilization from arsenic-loaded iron mineral phases affect filter performance over time. The long-term goal of this research is to better understand the microbial redox transformation processes that drive arsenic/iron mineral interactions in natural and engineered systems, such as household sand filters and to give recommendations for improved filter use and filter material disposal.
| 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 |