Water quality is an important criterion for evaluating the suitability of water for drinking and domestic purpose. The main objective of this study was to investigate the physicochemical characterization of groundwater for drinking water consumption. Ten captured sources were selected from three aquifers including the Guelma Mio-Plio-Quaternary alluvial basin; the Senonian Heliopolis Neritic limestone aquifer, and the Eocene limestones of Ras El Agba-Sellaoua aquifer. The analyses concerned the periods of high water in May 2017 and low water in August 2017. Twelve parameters were determined for the water samples: pH, T (°C), EC, Ca2+, Mg2+, Na+, K+, Cl−, HCO3−, SO42−, NO3−, TH (hydrotimetric degree), TAT (total alkalinity titration). The interpretation of the various analytical results allowed the determination of the chemical facies and the classification of the groundwater aquifers as follows: (i) in the alluvial layer, the gypsiferous marl substratum and the clays of the three terraces (high, medium and low) have given the water a chlorinated calcium chemical facies in the east part of the study area and travertines feeding partly alluvial layer, and have given a bicarbonated calcium water facies in the west, (ii) in the Senonian of Heliopolis limestone and Eocene carbonate formations of Ras El Agba-Sellaoua, the chemical facies are calcium bicarbonate. Water isotopes (δ18O and δD) helped to determine the origin of groundwater. Overall, the groundwater in the area is hard and has significant to excessive mineralization. It is progressively degraded in the direction of flow, especially in the Guelma alluvial aquifer.

No abstract

No abstract

In Algeria, soil erosion has experienced a spectacular extension, it is therefore imperative to assess the effects of this phenomenon. The purpose of this study is to assess soil loss rate using a GIS/USLE approach at the Mellegue watershed, northeast of Algeria. Geographic Information System techniques have been adopted to process data obtained at the study watershed, of reasonable spatial mapping, for the application of the RUSLE model. The model is a multiplication of the five erosion factors, namely rainfall erosivity, soil erodibility, slope and length of slope, plant cover and anti-erosion practices. Each of these factors has been expressed as a thematic map. The resulting soil loss map, with mean erosion rate of 20.40 T/ha/year, shows very low erosion (≤ 7 T/ha/year) which covers 64.60% of the total area of the basin, and very high erosion (> 60 T/ha/year) which does not exceed 4.80% of the basin area. The results indicate that Chabro and downstream Mellegue sub-watersheds face the greatest risk of soil erosion compared to Meskiana sub-basin, with contributions of 14.20 % and 12.90 % of their basin areas respectively. This is mainly due to natural factors and anthropogenic activities without appropriate conservation practices of agricultural land.

Purpose. In the electronics industry, stibium (Sb) is an important element used in the development of silicon-based devices. The metallogenic district of Guelma, known for its polymetallic antimony mineralization, is not currently exploited. The research purpose is to characterize the minerals and gang formations of antimony elements required as dopants during the growth of monocrystalline silicon. Methods. The research methods include detailed geological mapping and sampling, XRD mineralogical identification, XRF geo-chemical analysis, and atomic absorption spectrophotometry. Findings. The results obtained prove that Sb mineralization is the youngest in the North-East of Algeria, since it is hosted in the dolomitized lacustrine limestone of the Mio-Plio-Quaternary. The mineralization has been deposited by the replacement and filling open spaces. A supergene alteration of the Nadorite mineral has led to the antimony sulfides appearance. Originality. Unique mineral species of the world have been identified: Nadorite in Jebel Nador, Flajolotite in Jebel Heimel, valentinite in Jebel Senza, senarmontite in Jebel Hammimat, and cervantite near Aïn Kerma. The Ham-man N’Baïls deposits still contain significant reserves of Zn, Sb, and Pb. Practical implications. With the help of this study, we have answered questions related to the origin of the mineralizing fluids responsible for the formation of deposits. In addition to the epigenetic nature of the mineralization with the formation of unique and rare minerals throughout the world, the presence of gold in this region has been proven by chemical analysis.