Caractérisation Physico-Chimique Des Lixiviats Des Décharges : Cas De La Décharge Non Contrôlée De Niamey 2000 (Niamey-Niger)

Les lixiviats produits au niveau des décharges constituent un grand danger pour l’environnement. Dans le but de répondre aux questions d’un environnement sain, une analyse physico-chimique des lixiviats a été faite. Les prélèvements ont été effectués entre 13 et 16 heures au niveau de différents endroits de la décharge. Les paramètres déterminés sont : la température, le pH, la conductivité électrique, l’oxygène dissous, les matières en suspension, la turbidité, les cations (sodium, potassium, calcium, magnésium et ammonium), les anions (sulfate, chlorure, nitrate, ortho-phosphates et bicarbonate), les éléments traces métalliques (fer, cuivre, le chrome, le cadmium, le nickel, le cobalt et le zinc) par un spectrophotomètre DR 3800 de marque Hach, la DBO5 et la DCO. Les résultats des analyses montrent que les lixiviats produits à la décharge de Niamey 2000 sont basiques (pH minimal 7,6), très chargés en matières en suspension (590mg/L), très turbides (297NTU) et très pollués (oxygène dissous inférieur à 3mg/L). La pollution minérale est caractérisée par une forte conductivité électrique moyenne de 2441,5 μS/cm, une forte concentration en chlore (1276,5 mg/L) et en orthophosphates (3,31mg/L). La charge organique est traduite par une DCO moyenne de 2248mgO2/L et une DBO5 moyenne de 530mgO2/L. Les lixiviats étudiés sont caractérisés par des concentrations élevées en élément fer, zinc, cadmium et cuivre qui sont respectivement en mg/L de 9,26 ; 8,75 ; 0,19 et 2,3. Les éléments comme le nickel et le chrome sont présents à des teneurs inférieures aux limites fixées par la norme nigérienne de rejet. Landfill leachate is a great danger to the environment. In order to answer the questions of a healthy environment, the leachates produced at the Niamey 2000 landfill site were characterized. Samples were taken at various points around 1 and 4 o’clock in the landfill. The parameters determined are: temperature, pH, electrical conductivity, dissolved oxygen, suspended solids, turbidity, cations (sodium, potassium, calcium, magnesium and ammonium), anions (sulfate, chloride, nitrate) , ortho-phosphates and bicarbonate), metallic trace elements (iron, copper, chromium, cadmium, nickel, cobalt and zinc) by a Hach DR 3800 spectrophotometer, BOD5 and COD. The results of the analyzes show that the leachates produced at the Niamey 2000 landfill are basic (minimum pH 7.6), highly charged with suspended matter (590mg / L), very turbid (297NTU) and highly polluted (dissolved oxygen less than 3mg / L). The mineral pollution is characterized by a high average electrical conductivity of 2441.5 μS / cm, a high concentration of chlorine (1276.5 mg / L) and orthophosphates (3.31 mg / L). The organic load is translated by an average COD of 2248mgO2 / L and an average BOD5 of 530mgO2 / L. These leachates are characterized by high concentrations of iron, zinc, cadmium and copper which are respectively in mg / L of 9.26; 8.75; 0.19 and 2.3. Elements such as nickel and chromium are present at levels below the limits set by the Nigerian release standard

Traitement Des Phosphates Naturels De Tahoua (Niger) Par Quelques Acides Conventionnels

Within the framework of upgrading natural phosphate of Tahoua, a study was carried out on the dissolution of ore by inorganic acid (sulfuric acid, nitric acid) and organic acid (citric acid) solutions according to pH and attack time. The obtained results show a sudden drop of dissolution rate at pH above 2 and a dissolution almost zero beyond pH 4. The kinetic study shows fast dissolution of ore one hour after the attack. However, this dissolution is slow beyond one hour with few dissolved phosphorus during a relatively high period of time. Furthermore, the sulfuric acid solutions dissolve the ore better than those of citric and nitric acid: 41.07%; 37.03% and 35.64% of dissolved phosphorus respectively for sulfuric, citric and nitric acid solutions at the concentration of 1mol/L

IR AND UV-VISIBLE SPECTRA OF IRON(II) PHTHALOCYANINE COMPLEXES WITH PHOSPHINE OR PHOSPHITE

We have prepared and studied by vibrational and electronic spectrometry of a series of ferrophthalocyanine complexes with phosphine or phosphite axial ligands [PMe3, P(OMe)3, PPh3, P(OPh)3, PPh(OMe)3 and POH(OEt)2]. With PMe3, P(OMe)3 as ligands, only hexacoordinated complexes are obtained but with PPh3, P(OPh)3 and POH(OEt)2 as ligands, the coordination number depends on the FePc:ligand ratio in the reaction mixture. In the ratio 1:1 the complexes thus formed are pentacoordinated and in the ratio 1:2 hexacoordinated complexes are obtained. In the electronic spectra of hexacoordinated complexes, two charge-transfer transition bands, one at ~375 nm and the other at ~421 nm can be observed. We attribute the band at 375 nm to charge-transfer from axial ligand to macrocycle (CT Lax ® Pc) and the band at 421 nm to charge-transfer from metal to axial ligand (CT Fe ® Lax). In the IR spectra, the position of the n FeN4 band is linked to the coordination number; in the spectra of pentacoordinated complexes, its frequency is almost the same as that in the FePc spectrum but in hexacoordinated complexes, it moves to high frequencies. (Received September 10, 2001; revised February 26, 2002) Bull. Chem. Soc. Ethiop. 2002, 16(1), 73-79

First report of Salmonella meningitis in children during 2011-2015 meningitis surveillance in Niger

Meningitis due to salmonella is a rare infection poorly or not reported from NIGER. The infection is a complication of Salmonella infection that occurs in infants. Salmonella is the fourth cause of meningitis in Niger children, after Neisseria meningitidis, Streptococcus pneumoniae, and Haemophilus influenzae b. This retrospective study aimed to describe cases of salmonella meningitis in Niger infants. From January 2011 to December 2015, 6630 CSF collected nationwide were sent through an effective samples transport circuit already in place to allow the rapid delivery of thé CSF in CERMES, the National Reference laboratory-based meningitis surveillance for analysis. All turbid CSF from under 5 years patients were respectively cultured on Hektoen medium, Trypticase soy agar plate containing 5% sheep blood; and on chocolate agar plate. Gram negative bacilli were identified using API20 system. A total of 11/6630 (0.2%) Salmonella strains were isolated during the study. Most of the patients (72.7%) were less than 2 years old. The average age of children was 2.63 years with an extreme of 1 month to 14 years and the sex ratio M/F was 0.83. Of the eleven salmonella species detected, we found 7(63.6%) Salmonella typhi, 2 (16.7%) Salmonella spp, 1(8. 3%) Salmonella paratyphi A and 1 (8.3%) Salmonella paratyphi B. This study showed that Salmonella meningitis is a rare public health problem in Niger, despite the limitation on clinical symptoms data from patient case forms. Though, there was a risk which deserves to take salmonella in account in case of child meningitis. Published by the International journal of Microbiology and Mycology (IJMM

Extraction par Solvant de L’or par l’Aliquat 336 Et par le TOPO Dans des Solvants Apolaires

Au cours de ce travail, l’extraction liquide-liquide de l’or par un extractant neutre (TOPO) et un extractant anionique (Aliquat 336) dans une série de solvants a été étudié. L’influence du diluant, l’effet de la force ionique de la phase aqueuse et le temps d’agitation ont été également étudiés. L’or extrait a été analysé par la méthode spectrométrique UV-Visible. Les résultats de l’extraction ont montré que l’Aliquat 336 est un extractant potentiel de l’or avec un taux d’extraction de 99%. Par contre, le TOPO a donné un taux d’extraction moyen de 45%. Pour l’Aliquat 336, la désextraction en milieu aqueux a donné un faible rendement de 0,3%. Le meilleur rendement a été obtenu en milieu nitrique avec un pourcentage de 99% et cela en un temps record de 2 minutes. During this work, the liquid-liquid extraction of gold by neutral extractant (TOPO) and anionic extractant (Aliquat 336) in various solvents was studied. The influence of the diluent, the effect of the ionic strength of the aqueous phase and the kinetics time were also studied. The extracted gold was analyzed by the UV-Visible spectrometric method. The results of the extraction showed that Aliquat 336 is a potential gold with 99%. On the other hand, the TOPO gave an average extraction efficiency of 45%. For Aliquat 336, the stripping in aqueous medium gave low extraction efficiency of 0.3%. The best rate was obtained in a nitric medium with 99% and in record time of 2 minutes

Comparative Study of Solvent Extraction of Uranium with Alamine 336 and Aliquat 336: Application to the Uranium-Bearing Solutions of Niger Republic

This study focuses on the liquid-liquid extraction of uranium by anionic extractants of Alamine 336 and Aliquat 336. The objective of this study is to determine the parameters allowing the optimization of the extraction percentage of uranium, and other metals such as molybdenum, zirconium and vanadium. The extraction kinetics of uranium is achieved in 2 minutes. Sulfuric acid solutions are the media per excellence when using Alamine 336 as extractant. However,with Aliquat 336, it is orthophosphoric acid. Uranium is extracted at 99% in a single contact from the ratio: organic phase over aqueous phase (O/A) equals 1. The extraction of uranium with Alamine 336 depends on the initial pH of the aqueous phase as well as the Alamine 336 concentration. Alamine 336 tends to release the uranium and the extracted zirconium until the 3 rd contact to the benefit of the molybdenum due to the natural occurrence of −,3 − and − ions in the uranium-bearing solutions which have the tendency of breaking the anion complexes. Vanadium, which is not extracted by Alamine 336 and Aliquat 336, can, in the hydrodynamic conditions of this work, be extracted by increasing the redox potential to 800 mV and pH ≥ 1

Development of Compost from Agro-food Residues: Analysis of the Crop Nutrients and Trace Elements

A composting study of agro-food residues was conducted to evaluate the nutrient content of plants. Three types of composts were made: compost C1 based on organic matter; compost C2 based on organic matter and Tahoua rock phosphate and compost C3 based on organic matter, cow manure and Tahoua rock phosphate. During composting, the pH reached 9.60; 8.93 and 8.88 respectively for composts C1, C2 and C3 before falling respectively to 9.15; 7.90 and 7.83 at the end of composting. The temperature reached 57 ° C for all composts during composting before stabilizing at 31 ° C after composting. The analysis of the physicochemical parameters of the composts obtained reveals that they contain carbon contents (23.01%, 14.625% and 16.575% for C1, C2 and C3 respectively) and nitrogen (2.63%; 34% and 1.62% for C1, C2 and C3 respectively) and C / N ratios (8.74, 10.91 and 10.83 for C1, C2 and C3 respectively) and nutrients: available phosphorus (186.2, 399.70, 695.8 mg / kg for C1, C2 and C3 respectively), potassium (3389.97, 1127; 1313.30 for C1, C2 and C3 respectively), calcium (12000, 42800, 64000 mg / kg for C1, C2 and C3 respectively) and magnesium (18936.77, 15946.62, 16346.47 mg / kg for C1, C2 and C3 respectively)

O OR RI IG GI IN NA AL L A AR RT TI IC CL LE E Assessment of Dissolved Phosphate Rate in the Obtained Compounds by Partial Acid Attacks of Tahoua Natural Phosphate Niger

ABSTRACT Partial seizures with certain mineral acids o