The aim of this present study is to determine the physicochemical properties of atmospheric particles in commune 5 of the Niamey region. For this purpose, the determination of the atmospheric physical and chemical properties was carried out using a low-volume sampler, a Davis-type weather station, a balance high sensitivity, The Thermo XL2 and the black carbon reflectometer. The pollutants concerned by this study are mainly fine particulate matter (PM2.5), black carbon and heavy metals such as Cr, Cu, Hg, Mn, Ti, V, Zn, Ba, Fe and Sr. According to the result of this study which is carried out over 30 days, the PM2.5 concentrations of air measured were between 0 and 286.54 μg/L with a mean value of 11.65 μg/L. The temperature values were between 24 and 27 °C with an average value of 25.3°C. The humidity value of measured air varies between 8 and 17 % with a mean value of 13.3 %. The measured wind speed values are between 3.24 and 6.48 Km/h with an average value of 4.14 Km/h. According to World Health Organization guidelines the PM2.5, Mn, Hg, Ba, Cr and black carbon concentrations measured during this study exceeded the permissible limit values. Correlation analysis results highlighted a strong correlation between Mn-Fe, Mn-Zn, Mn-Ti, Mn-V, Mn-Cr, Zn-Ti, Zn-V, Zn-Cr, Ti-V, and Ti-Cr indicating that these ions come from a common source. According to principal component analysis for heavy metals, three principal factors that explain 87.34% of the total variance have been formed. Component 1 includes V, Zn, Ti and Cr with a variance value of 56.067 %; the second factor includes Ba and black carbon with a variance value of 19.665 % and the third factor is only represented by Sr with a variance value of 11.612 %. The high value of variance observed in the first group of components indicated that V, Zn, Ti and Cr are the main pollutants that control the air pollution in the study area.

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The aim of this study is to determine the origins of salinization and the main hydrogeochemical process that controls the chemistry of Çarşamba coastal aquifer in Turkey. Therefore, a total of 33 groundwater samples and three seawater samples were analyzed in the coastal region of Çarşamba Plain in July 2019 and for these samples’ physical parameters, major ions and environmental isotopes (δ18O, δ2H and 3H) values were determined. Piper, Chadha, Gibbs diagrams and Stuyfzand Classification Systems were used to determine the origins of salinization and the key hydrogeochemical process controlling the groundwater chemistry. According to Stuyfzand classification system, the study showed that the freshwater and fresh-brackish water main types are the most widespread in the study area. Six water subtypes were observed in the study area that include CaHCO3, CaMix, NaMix, NaCl, NaHCO3 and MgHCO3. In addition, the subtypes CaMix indicated the locations of the transition zone, where the groundwater rich in Ca and HCO3 and gradually enriched in Na changes from CaMix with HCO3 as dominant anion to eventually CaCl and NaCl subtypes. Furthermore, the subtypes NaMix, NaHCO3 and MgHCO3 showed the locations of the transition zone where the flushing of the saline aquifer by freshwater takes place. All groundwater samples from study area had a positive cation exchange code and show that four hydrogeochemical facies composed of CaHCO3; Ca-Mg-Cl and NaCl and NaHCO3. Besides, groundwater samples have been influenced by two main mechanisms: the water-rock interaction and evaporation-crystallization. According to δ18O, δ2H and 3H analysis, the water samples have meteoric origin, shallow circulation, and a short residence time.

The aims of this study is to identify the behavior of the sealing grout in the Izegouandane and Tarât aquifers, which are the main water supply sources in the northern region of Niger, in order to prevent contamination and reduce the impact of uranium mining activities on the groundwater. This study also made it possible to evaluate the conformity of the mixing water as well as the bearing capacity of the grout in the aquifers crossed in order to verify its conformity. The study area is located in a desert zone in the northern band of Niger, in Arlit city. The measured compressive strengths are 60 bars for cylinder A, 52.5 for cylinder B and 62.5 for cylinder C with an average value of 58.33 bars. The deduced base stress value is 2.24 MPa. The sampled mixing water has a pH of 8.7 with a suspended solids content of 0.02g/l, a Cl- concentration of 93 mg/l and nitrate and nitrite concentration values that are 5 mg/l and 12 mg/l respectively. These waters comply with the general specifications of the standards relating to the quality of mixing water and can therefore be used to fill in boreholes. The analysis of groundwater shows that for Izegouandane and Tarat aquifers the values of concentration of suspended solids are respectively 0.04 g / L to 0.001 g / L. The values of Ph of these waters are 8.7 and 8.1 respectively for the water table of Izegouandane and Tarat. The analysis of Izegouandane aquifer showed that the concentrations of chloride, nitrates and sulfates are respectively 32 mg/L, 9 mg/L and 36 mg/L. Those of magnesium, ammonium and carbon dioxide, they are respectively 1.5 mg/L, 0.8 mg/L and 0.5 mg/L. For the Tarat aquifer, the concentrations of chloride, nitrates and sulphates are respectively 47 mg/L, 29.5 mg/L and 47 mg/L. As for magnesium, ammonium and carbon dioxide, they are respectively 10.02 mg/L, 1.6 mg/L and 1.6 mg/L.