Das Projekt "Bedeutung des Fluors im Boden auf den Fluorgehalt in Futtergras" wird vom Umweltbundesamt gefördert und von Eidgenössische Forschungsanstalt für Agrikulturchemie und Umwelthygiene durchgeführt. Buts: Quelle est l'importance du fluor edaphique sur la teneur en fluor d'une graminee fourragere? Existe-t-il une relation entre les concentrations en fluor de l'air et celles des plantes dans les conditions actuelles? Quelle est l'importance de la contamination fourragere? Jusqu'a quelle distance de l'usine les fourrages sont-ils contamines et dans quelle mesure sont-ils encore utilisables? (FRA)
Das Projekt "Optimization and acceptance of fluoride removal options for drinking water in rural Ehiopia" wird vom Umweltbundesamt gefördert und von Eawag - Das Wasserforschungsinstitut des ETH-Bereichs durchgeführt. The aim of the research project is to further develop and compare the acceptability and technical performance of fluoride removal filters and to explore ways of sustainably implementing these in rural Ethiopia. According to estimates of the Ethiopian Ministry of Water Resources more than 14 million people in Ethiopia rely on drinking water contaminated by fluoride in the Rift Valley region. Over 40Prozent of deep and shallow wells are contaminated and concentrations, up to 26 mg/L, are significantly higher than the present international WHO guideline value of 1.5 mg/L. The main source of fluoride are the basaltic rocks in the Rift Valley. Over 80Prozent of children suffer from different degrees of dental fluorosis and skeletal fluorosis is increasing, mainly among older people. The mitigation of this health problem has been hampered mainly by the lack of a suitable, inexpensive removal method. A switch to treated surface waters for drinking is being discussed, but it is accepted that fluoride removal systems for rural communities are required. To date there has been no successful implementation of such a system in Ethiopia. This project aims to combine technical and social research at both Eawag and University of Addis Ababa, including field work together with NGOs to find a solution to the mitigation of fluorosis. Not only the suggested removal techniques but also the inter- and transdisciplinary research approach is innovative. Intensive interaction of engineering and social sciences is indispensable in this project, because even the best technical solution is useless when it is not accepted by the population. This collaborative project also has an important goal of capacity and human resource development in Ethiopia. It aims at strengthening the knowledge and research capacity of the Ethiopian university and the participation of NGOs will consolidate the ties between research and implementation. Furthermore, the results will be applicable not only to Ethiopia but also for other fluorosis-affected developing countries. Two fluoride removal systems that can cope with the elevated fluoride concentrations will be further developed and tested in the field. The first, based on filtration with aluminium (Al) oxide, has been developed in the Chemistry Department of Addis Ababa University. Laboratory tests have shown a very high removal capacity, but still further laboratory and field testing is required. The second filter material is based on a calcium hydroxyapatite, including bone char, that is successfully being developed and currently implemented by the Catholic Diocese of Nakuru (CDN) in Kenya. Preliminary implementation studies with bone char filtration in Ethiopia, carried out by the NGO consortium Swiss Interchurch Aid (HEKS) / Oromo Self-Help Organisation (OSHO) in collaboration with CDN and Eawag have shown that the water composition, the high fluoride concentrations,
Das Projekt "Optimization of coprecipitation processes in apatite-based filter materials for the removal of fluoride from drinking water" wird vom Umweltbundesamt gefördert und von Eawag - Das Wasserforschungsinstitut des ETH-Bereichs durchgeführt. The aim of the research project is to optimize the function of a calcium phosphate filter material for implementation in developing countries. It is estimated that more than 200 million people worldwide rely on drinking water with fluoride concentrations exceeding the WHO guideline of 1.5 mg/L. Excess fluoride intake causes different types of fluorosis, primarily dental and skeletal fluorosis, depending on the level and period of exposure. Fluoride is the 13th most abundant element in the earth crust and often has a natural rock-derived origin in groundwater. Fluoride levels appear to be controlled by the precipitation of a calcium fluoride mineral (fluorite). Groundwaters with low dissolved calcium contents appear to have higher fluoride concentrations. For similar reasons alkaline sodic groundwaters in which calcium is not soluble, mainly found in arid climates appear to have elevated fluoride contents. While industrialized countries commonly use activated alumina to remove fluoride from drinking water, fluoride removal is yet uncommon in low and middle-income countries. Insufficient removal efficiency, complicated maintenance and/or unaffordable costs particularly for rural population are the main reasons why implementation in developing countries is still rare. Bone char as a filter media is available and has been implemented on a local scale in different countries such as Kenya, Tanzania, and Thailand. Bone char contains hydroxyapatite, a Ca phosphate mineral. Fluoride is primarily removed by the exchange of the hydroxide ion for fluoride. Filter life can be prolonged by a factor of ten with the addition of dissolved calcium and phosphate ions that precipitate on available hydroxyapatite surfaces. It is desirable to develop apatite-based filter materials that do not depend on bone char, which is difficult to produce and may not be accepted because of ethical reasons in some countries. Preliminary experiments have demonstrated the feasibility of using hydroxyapatite granules instead of bone char. It is proposed to examine the processes that control surface precipitation on hydroxyapatite. In model systems, the surface precipitation rate of fluor/hydroxyapatite with addition of dissolved calcium and phosphate will be examined under neutral to slightly alkaline pH conditions. The influence of silicate, sulphate and carbonate, which are known to be incorporated in apatite minerals, will be studied. The structure of bone char and hydroxyapatite granules will be examined using spectroscopic, microscopic and wet-chemical techniques and the results will be used to interpret column experiments. This work is part of cooperative project with a Kenyan non-governmental organization that is currently the main producer of bone char-based filtration systems in the Rift Valley. . The ultimate aim is to develop a Rift-Valley network of organizations that can produce and maintain fluoride removal filter units.
Das Projekt "Regionalisierung geogener Schwermetall- und Fluorgehalte in Boeden der Schweiz" wird vom Umweltbundesamt gefördert und von Eidgenössische Technische Hochschule Zürich, Institut für Mineralogie und Petrographie durchgeführt. Schwermetall (SM): Pb, Cd, Cr, Co, Cu (Mo), Ni, Hg (Tl), Zn: Geologische, petrographische und mineralogische Charakterisierung von Gesteinsfacies, die als pedogenetisches Ausgangsgestein in der Schweiz von Bedeutung sind. Kartierung der pedogenetischen Ausgangsgesteine unter Beruecksichtigung von Gletscher- und Flusseinzugsgebieten ('Sedimentationsprovinzen'). Sammeln und Zusammenstellen von Elementgehalten entsprechender Gesteine und C-Horizonte aus Literatur und anderen Quellen (z.B. Nagra-Bohrungen). Festlegen von repraesentativen Bodenprofilen in Bezug auf die Ausgangsgesteine in verschiedenen Sedimentationsprovinzen. Elementanalysen der Gesteinsproben und Bodenprofile, insbesondere der C-Horizonte. Raeumliche Ausscheidung von geogenen SM- und F-'Provinzen' in der Schweiz. Detailstudie der raeumlichen Variabilitaet der geogenen Gehalte im Testgebiet Furttal (ZH) und evt. weiteren Gebieten.