Das Projekt "NOIRAIGUE - Teilprojekt A: Beschreibung und Quantifizierung des Oberflaechen- und Grundwassersystems" wird vom Umweltbundesamt gefördert und von Universite de Neuchatel, Institut de Geologie, Centre d'Hydrogeologie durchgeführt. Colloids and particles are recognize as a major vector of pollutant transport. In this project, we focus on the influence of the water cycle on colloids and particles dynamic in a karstic aquifer covered by peat and agricultural land. We want to determine the hydro geological situations which deliver the most important fluxes of colloids. On one hand, we presently study the basin by field exploration and geophysical techniques to describe the major pass ways of water from atmosphere to spring. This should allow the delimitation of areas generating the most colloids. On the other hand we follow the particle distribution (PSD, from 0.05 to 60 mym) in water at different levels of the Noiraigue basin using many methods. The PSD is highly influenced by discharge both in the Bied brook and in the Noiraigue spring. More results should allow the description of the physical factors governing the movement of each size fraction of colloids. Complementary information: Noiraigue: Subproject A: 'Characterisation and quantification of the surface and groundwater system': Colloids and particles are recognized as a major vector of pollutant transport. In this project, we focus on the influence of the water cycle on colloids and particles dynamic in a karstic aquifer covered by peat and agricultural land. We want to determine the hydro geological situations which deliver the most important fluxes of colloids. On one hand, we presently study the basin by field exploration and geophysical techniques to describe the major pass ways of water from atmosphere to spring. This should allow the delimination of areas generating the most colloids. On the other hand, we follow the particle distribution (PSD, from 0.05 to 60 Nanometers) in water at different levels of the Noiraigue basin using many methods. The PSD is highly influenced by discharge both in the Bied brook and in the Noiraigue spring. More results should allow the description of the physical factors governing the moment of each size fraction of colloids. Noiraigue: Subproject B (B. Kubler): 'Organic and mineral colloidal particles in water from swamp soils to spring in karst system': Colloids and particles are recognized as a major vector of pollutant transport. This project aims to characterize these colloids in soil, groundwater and rivers of the Noiraigue spring basin. We determine the particle size distribution in water using many different methods (filtration, ultra centrifugation, laser sizer, chromatography, electronic microscopy) in order to perfect a methodology applicable to field.
Das Projekt "NOIRAIGUE - Teilprojekt B: organische und mineralische Kolloidpartikel im Wasser von Sumpfboeden an Quellen in Karstsystemen (OMIPAWAKA)" wird vom Umweltbundesamt gefördert und von Universite de Neuchatel, Institut de Geologie durchgeführt. In the catchment area of the Noiraigue system two types of waters are present: 1. weakly polar, acid, reduced waters with organic material stemming from natural peat bogs and 2. moderately polar waters containing organic material stemming from improved swamps. The two waters mix with each other and are thereby neutralized before entering the karst drainage system. The colloid's nature, fluxes and impact on the neutralization is the main topic of the present investigation. Since fluxes are highly dependent on season and rain fall, the study of the hydrologic systems is an important part of this project (subproject A). Since colloids are partially produced by biologic activity, the microbiologic system is studied in subproject C (e.g. Gallionella). During transport in the karst system, the waters loose about half of their organic material content. Colloids at the karst spring will be compared with those at the karst entrance in order to quantify the influence of the residence time within the karst system as well as transport and oxidation processes. Tracing of bacteria using bacteriophages will permit to quantify the transfer time of organic particles of 1 mym size in comparison with the smaller colloid particles.