The Stimulation of Nitrification in an Organically Enriched Soil by Zeolitic Tuff and its Effect on Plant Growing

The adsorption and ion-exchange properties of natural zeolite minerals such as phillipsite, clinoptilolite and mordenite are well studied and these microporous minerals are known to have a high selectivity towards the ammonium ion. Natural zeolites are often found as alteration products of volcanic glass, in deposits of volcaniclastic sediment. In such rocks they are very abundant and commonly exceed 80 percent of the mineral assemblage. Due to their high selectivity towards ammonium ions, rocks containing these minerals can be used to adsorb ammonia from sewage and organic farm waste. It has now been found that a composted mixture of the crushed zeolitic tuff and organic waste will enhance nitrification in soils, when added as an amendment. During composting ammonia, derived from the biological degradation of the organic waste, is adsorbed and ion-exchanged by the zeolite minerals present in the mixture. When added to a soil, nitrification occurs as a result of oxidation of the ammonium ions, first to nitrite and then further to nitrate, together with the production of protons. These reactions were studied in a time-course experiment using the analysis of aqueous leachates taken from untreated and amended soil substrates. Nitrification trends were observed and a linear relationship was found between the electrical conductivity (EC) and the nitrate concentration of the leachates; demonstrating how the ionic mobility of the substrate porewater increases with increase in the degree of nitrification. A comparison of plant growth in substrates without zeolitic tuff with those amended with the organo-zeolitic mixture, showed that plant growth in the amended soil is greatly increased

Organo-zeolitic treatment of mine waste to enhance the growth of vegetation

Zeolitic tuff containing an appreciable abundance of clinoptilolite was composted with animal waste to produce a dry friable non-odorous material that can easily be mixed with soil to produce an amended soil substrate. In earlier work it was found that leachate samples taken from organo-zeolitic treated substrates had nitrate concentrations an order of magnitude greater than those without the amendment. Comparative analysis of separate batches of organic- soil mixtures had shown that those containing zeolitic tuff had a very much higher concentrations of nitrate, in their leachate samples, than those containing only animal manure. Clinoptilolite has an ion-exchange property that is highly selective towards ammonium and it appears that the clinoptilolite component in adsorbing and ion-exchanging ammonia, as it is liberated from the decomposing animal waste, "buffers" its loss from volatilization and leaching. As a result, ammonium oxidizing micro-organisms are stimulated, which leads to enhanced nitrification and increasing ionic mobility of the substrate pore water. These functions allow plant growth to be stabilized on acid mine waste in such a way as to favour luxuriant growth on such sites, which normally are devoid of vegetation. The chemical analysis of plant leaf and stem tissue has identified trends in nutrient uptake and an attempt is made to understand the mechanisms responsible for this behaviour

Health Indicators in the European Regions - ISARE II

Most comparisons of health data in Europe take place at the national level. However, there is increased interest in looking at health data at a sub-national level. This is because of the increased importance in many European countries, of regions and devolved powers to them. This study aimed to establish the availability of health data at a regional level and to construct an experimental database. Methods: Using a network of country correspondents, data were collected on a series of topics from all the regions of that country. In addition, a supplementary list of data was collected from one region of each country. Results: Out of the then 15 Member States of the European Union (EU), 14 countries participated in the study. Thirteen countries were able to supply data. Where data were available, using the criteria we developed, these were of relatively good quality. Data on mortality was most readily available, but data on the important public health topics such as obesity was much more difficult to obtain, and absent in many cases. Conclusions: It is possible to construct a database and a resultant set of indicators for relevant sub-national areas of Member States in the EU. This is not likely to be achieved through current routine data collection systems unless significant changes are made to the data collection processes such as those undertaken by Eurostat. There is, also, an urgent need to introduce comprehensive sub-national data collections on important public health topics such as obesity and smoking

Fractures, hydrothermal alterations and permeability in the Soultz Enhanced Geothermal System.

International audienc

Bias-corrected CHIRP [Climate Hazards Group InfraRed Precipitation] satellite rainfall for water level simulation, Lake Ziway, Ethiopia

Applicability of satellite rainfall products must be explored since rain gauge networks have limitations to provide adequate spatial coverage. In this study, Climate Hazards InfraRed Precipitation (CHIRP) satellite-only product was evaluated for rainfall-runoff modeling whereas the simulated runoff served as input to simulate the water levels of Lake Ziway from 1986 to 2014. CHIRP dataset was bias-corrected using power transformation and used as input to Hydrologiska Byråns Vattenbalansavdelning (HBV) model to simulate streamflow of Meki and Katar catchments. Results showed that gauged catchments of Meki and Katar contributed 524 and 855 mm to the annual lake inflow, respectively. The estimated runoff from ungauged catchments is 182 mm that amounts to approximately 8.5% of the total lake inflow over the period 1986–2000. The results of lake level simulation show good agreement from 1986 to 2000, but deteriorating agreement after 2000, which is mainly attributed to errors in water balance terms and human-induced impacts. For the period 1986–2000, the water balance closure error for the lake was 67.5 mm per year, which accounts for 2.9% of the total lake inflow from rainfall and river inflow. This study shows bias correction increases the applicability of CHIRP satellite product for lake water balance studies

Fracture analysis and reservoir characterization of the granitic basement in HDR Soultz project (France)

International audienceWithin the framework of the European Hot Rock (HDR) project, the natural fracture geometry of the deep granitic basement in the Upper Rine Graben has been studied at Soultz-sous-Forêts (France). The porphyritic granite is characterized by hydrothermally altered and fractured sections. Detailed structural analysis of continuous core samples and borehole wall imagery indicates that fracture zones constitute a complex network of fault segments dominated by N-S trends in accordance with the geometry of the local Soultz horst structure.Some of these fault segments still carry hydrothermal brines. The attitude of the faults is closely related to rifting of the graben during the Tertiary. The fractures strike in a direction nearly parallel to the maximum horizontal stress. In this favorable situation, hydraulic injection will tend to reactivate natural fractures at low pressures

Implications of water abstraction on the interconnected Central Rift Valley Lakes Sub-Basin of Ethiopia using WEAP

Study region: Central Rift Valley Lakes sub-basin, Ethiopia. Study focus: The competition for water is rapidly increasing in Central Rift Valley lakes sub-basin due to the combined effect of various water resources developments. However, the impacts of recent and future water resources development pathways on the water balance of the three interconnected lakes (i.e. Lake Ziway, Langano and Abiyata) are unknown. The Water Evaluation And Planning (WEAP) model was used to assess the development impacts on water resources of the interconnected lakes. We considered three development pathways that are, recent (2009–2018), short-term (2019–2028) and long-term development (2029–2038). Lake Ziway water inflows from six catchments were estimated using the Hydrologiska Byråns Vattenbalansavdelning (HBV) rainfall-runoff model. Crop water requirements for irrigation schemes were estimated by the CROPWAT model. New hydrological insights for the region: WEAP simulations show a total water demand of 102.3 Mm3 under the recent development pathway that increases by 46% and 118% for short-term and long-term development pathways, respectively. This will notably affect the water balance of the interconnected lakes and cause an unmet water demand of 47.9 Mm3 for the long-term (2028–2038). For Lake Ziway and Abiyata, water levels will decrease substantially to cause water scarcity in the long-term, and developments in Lake Ziway will significantly affect water storage in Lake Abiyata storages in Lake Abiyata. Overall, future developments will threaten the water resource of the interconnected lake system

Le programme national nutrition santé (PNNS): bilan des études et résultats observés

info:eu-repo/semantics/publishe

Etude sur la contraception et la prevention des MST a l'adolescence Une etude par entretiens aupres des 15-20 ans a Beziers

SIGLEAvailable from INIST (FR), Document Supply Service, under shelf-number : RP 15826 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc