scholarly journals Caractérisation physico-chimique des eaux d’un système lacustre du cordon littoral ivoirien : cas du lac Labion

2020 ◽  
Vol 14 (5) ◽  
pp. 1878-1892
Author(s):  
Ella Odjohou ◽  
Mireille Amani ◽  
Gbombélé Soro ◽  
Sylvain Monde

L’analyse spatio-temporelle des paramètres physico-chimiques des eaux du lac Labion dans le système lagunaire ivoirien, a été abordé dans un contexte de variabilité climatique. L’objectif est de caractériser la physico-chimie des eaux au cours des saisons climatiques. Pour y parvenir, une analyse hydrologique a été réalisé à partir de mesure in situ des paramètres pH, Température, Conductivité électrique, Oxygène dissous, Matières en suspension, Transparence et Turbidité. Ces paramètres ont été mesurés à l’aide d’un multi-paramètre. Celui-ci est mis à l’eau et les résultats s’affichent à l’écran. Seule la transparence a été mesuré à l’aide du disque de Secchi. La température (31 °C) indique des eaux relativement chaudes. Quant au pH, il varie du neutre (6,79) à alcalin (8,99). La conductivité moyenne sur le lac est de 40 μS/cm. Les eaux sont bien oxygénées (7 à 8 mg/L) et présente peu de matières en suspension. L’analyse en composante principale montre une forte corrélation (r > 0,7) entre les variables température, oxygène, pH et conductivité. Ces résultats mettent en évidence deux (02) mécanismes qui sont à l’origine des forçages naturel et artificiel. Il s’agit du mécanisme de la photosynthèse occasionnant une bonne oxygénation des eaux et du mécanisme de pollution traduisant une forte turbidité.Mots clés : Lac, saison climatique, paramètre, mécanisme, évolution.   English Title: Physico-chemical characterization of the waters of a lake system of the ivorian coastal cordon: case of Lake LabionThe spatio-temporal analysis of the physicochemical parameters of the waters of Lake Labion in the Ivorian lagoon system was tackled in the context of climate variability. The objective is to characterize the physico-chemistry of the waters during the climatic seasons. To achieve this, a hydrological analysis was carried out using in situ measurement of the parameters pH, Temperature, Electrical conductivity, Dissolved oxygen, Suspended matter, Transparency and Turbidity. These parameters were measured using a multi-parameter. It is launched and the results are displayed on the screen. Only transparency was measured using the Secchi disk. The temperature (31 °C) indicates relatively warm waters. As for the pH, it varies from neutral (6.79) to alkaline (8.99). The average conductivity on the lake is 40 μS / cm. The waters are well oxygenated (7 to 8 mg / L) and have little suspended matter. The principal component analysis shows a strong correlation (r> 0.7) between the variables temperature, oxygen, pH and conductivity. These results highlight two (02) mechanisms which are at the origin of natural and artificial forcings. This is the mechanism of photosynthesis causing good oxygenation of water and the pollution mechanism reflecting high turbidity.Keywords: Lake, climatic season, parameter, mechanism, evolution.

Author(s):  
Edem K. Kolédzi ◽  
Nitale M’Balikine Krou ◽  
Kwamivi N. Ségbéaya ◽  
E. Aziablé

This study aims to determine the parameters measuring the reduction rate of the organic matter during fermentation and its bio-availability after maturation of the compost made using fermentable fractions of household waste. Thus, a physico-chemical characterization of the raw leachate and the leachate treated with lime and caustic soda was carried out. The results showed that, the contents of the other parameters measured are higher for the raw leachate compared to those obtained for the treated leachate. Organic and inorganic pollution is reflected by high Chemical Oxygen Demand (COD), absorbance at 254 nm, turbidity and suspended matter. The COD values ​​in the raw leachate vary between 13000 and 19150 mg/O2/L; those of the absorbance at 254 nm between 30.5 and 34.15 OD; those of turbidity between 156 and 255 NTU (Nephelometric Turbidity Unit) and those of suspended matter between 48 and 1600 mg/L. In the treated leachate, the COD values ​​oscillate between 4489 and 8743 mg/O2/L; those of the absorbance at 254 nm between 6.69 and 31.1 OD; those of turbidity between 57.8 and 122 NTU and those of suspended matter between 70 and 92 mg. These results reflect a good reduction after treatment with lime and soda.


Life ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 72
Author(s):  
Eva Mateo-Marti ◽  
Olga Prieto-Ballesteros ◽  
Guillermo Muñoz Caro ◽  
Cristobal González-Díaz ◽  
Victoria Muñoz-Iglesias ◽  
...  

At present, the study of diverse habitable environments of astrobiological interest has become a major challenge. Due to the obvious technical and economical limitations on in situ exploration, laboratory simulations are one of the most feasible research options to make advances both in several astrobiologically interesting environments and in developing a consistent description of the origin of life. With this objective in mind, we applied vacuum and high pressure technology to the design of versatile simulation chambers devoted to the simulation of the interstellar medium, planetary atmospheres conditions and high-pressure environments. These simulation facilities are especially appropriate for studying the physical, chemical and biological changes induced in a particular sample by in situ irradiation or physical parameters in a controlled environment. Furthermore, the implementation of several spectroscopies, such as infrared, Raman, ultraviolet, etc., to study solids, and mass spectrometry to monitor the gas phase, in our simulation chambers, provide specific tools for the in situ physico-chemical characterization of analogues of astrobiological interest. Simulation chamber facilities are a promising and potential tool for planetary exploration of habitable environments. A review of many wide-ranging applications in astrobiology are detailed herein to provide an understanding of the potential and flexibility of these unique experimental systems.


Alergologia ◽  
2020 ◽  
Vol 1 (4) ◽  
pp. 7
Author(s):  
Mariana Vieru ◽  
Florin-Dan Popescu ◽  
Laura Haidar ◽  
Carmen Bunu-Panaitescu

2010 ◽  
Vol 35 (5) ◽  
pp. 261-267 ◽  
Author(s):  
Wissemn Gallala ◽  
Mohamed Essghaier Gaied ◽  
Borhen Kchaou

2001 ◽  
Vol 71 (3) ◽  
pp. 342-349
Author(s):  
Lucian Eva ◽  
Letitia Doina Duceac ◽  
Liviu Stafie ◽  
Constantin Marcu ◽  
Geta Mitrea ◽  
...  

The fourth generation cephalosporin antibacterial agent, cefepime, was loaded into layered double hydroxides for enhancing antibiotic efficiency, reducing side effects, as well as achieving the sustained release property. The intercalation of antibiotic into the inter-gallery of ZnAl-layered double hydroxide (LDH) was carried out using ion exchange method, by this constituting a nano-sized organic-inorganic hybrid material for a controlled release novel formulation. Although cefepime is a broad spectrum antibiotic, it has various adverse effects and a significant degradation rate. Thus, the preparation and physico-chemical characterization of nanomaterials able to intercalate this drug is an important study for medical and pharmaceutical field. The antibiotic inclusion into LDHs nanostructure was confirmed by advanced characterization techniques and the release profile of cefepime was analysed with the respect to pH of the simulated media.


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