Université N D S T E I de mathém (original) (raw)

Papers by Université N D S T E I de mathém

Theoretical and applied climatology, Jan 31, 2024

Malaria journal, Mar 15, 2024

Background Vegetation health (VH) is a powerful characteristic for forecasting malaria incidence ... more Background Vegetation health (VH) is a powerful characteristic for forecasting malaria incidence in regions where the disease is prevalent. This study aims to determine how vegetation health affects the prevalence of malaria and create seasonal weather forecasts using NOAA/AVHRR environmental satellite data that can be substituted for malaria epidemic forecasts. Methods Weekly advanced very high-resolution radiometer (AVHRR) data were retrieved from the NOAA satellite website from 2009 to 2021. The monthly number of malaria cases was collected from the Ministry of Health of Benin from 2009 to 2021 and matched with AVHRR data. Pearson correlation was calculated to investigate the impact of vegetation health on malaria transmission. Ordinary least squares (OLS), support vector machine (SVM) and principal component regression (PCR) were applied to forecast the monthly number of cases of malaria in Northern Benin. A random sample of proposed models was used to assess accuracy and bias. Results Estimates place the annual percentage rise in malaria cases at 9.07% over 2009-2021 period. Moisture (VCI) for weeks 19-21 predicts 75% of the number of malaria cases in the month of the start of high mosquito activities. Soil temperature (TCI) and vegetation health index (VHI) predicted one month earlier than the start of mosquito activities through transmission, 78% of monthly malaria incidence. Conclusions SVM model D is more effective than OLS model A in the prediction of malaria incidence in Northern Benin. These models are a very useful tool for stakeholders looking to lessen the impact of malaria in Benin.

International Journal of Innovation and Applied Studies, Dec 2, 2015

By searching of physico chemical characterization of the pollutants in the leachates of the Sanit... more By searching of physico chemical characterization of the pollutants in the leachates of the Sanitary Burying Place of Ouèssè-Ouidah, it has been determined parameters such as the temperature, the electric conductivity, the pH, the dissolved oxygen, the redox potential, the anions (Chloride, Nitrate, Nitrite, Sulfate), the cations (Sodium, Potassium, Calcium, Magnesium, Ammonium), metals (Iron, Nickel, Lead, Aluminum, Zinc), the DBO5 and the DCO. The obtained results show that the leachates of the L.E.S. are turbid (> 1100NTU), charged in suspended materials (> 470mg / L) and then very polluted (oxygen dissolved approximately 1mg / L). Leachates are also characterized by a strong iron content (1829,15 ±2,82-2099,49±12,82 µg / L) and a strong concentration in chloride (192,49 in 227,89mg / L). The content of samples studied in oxidizable materials (DCO of the order of 1161,0-1278,0 mgO2 / L; DBO5 of the order of 95,8 in 107,0 mgO2 / L) and in nitrogenous materials (220 in 400 mg / L), which remained very high. The samples of the analyzed leachates also have a high rate of minerals (conductivity: max = 218 ms / cm).

International Journal of Innovation and Applied Studies, Apr 2, 2018

The objective of this study is to evaluate the quality of underground water according to the stan... more The objective of this study is to evaluate the quality of underground water according to the standards of Beninese and international drinkability. The choice of watering place centres on daily usages as beverage. The physicochemical and bacteriological parameters have been determined according to the conventional methods. The obtained results show that the studied waters are characterized by an acidic-pH (6.74-6.95), a temperature which varies from 27.3°C to 30.4°C, a weak electric conductivity (8.9μS/cm-588 μS/cm), weak TDS (5mg/L-270mg/L) and a low potential of reduction-oxidation (202 mV-344 mV). Besides, the following medium concentrations have been obtained : Sulphate (0.19 mg / L-36.55 mg / L), Nitrate (4.60 mg / L-53.28 mg/L), Calcium (0.7 mg/L-57.46 mg/L), Potassium (0.22 mg/L-21.02 mg/L), Magnesium (0.01 mg/L-18.33 mg/L), ammonium (0.02 mg/L-18.33 mg/L) and Chloride (0.20 mg / L-55.55 mg/L). Among the studied places, only the well P1 revealed contents in potassium and in nitrate beyond the standards of drinkability. The results of bacteriological analysis confirm the presence in very appreciable numbers of fecal contaminated indicators (Total Coliforms, Fecal Coliforms and Escheriachia-Coli) in the wells except the well P5. Moreover, the Fecal Streptococci have been displayed prominently in the well P6. So at the end of this study, we can deduce that wells studied waters roughly present the serious health risks to the population contrary to the drilling wells and springs water.

The American Journal of Tropical Medicine and Hygiene, 2010

Background Malaria is one of the major vector-borne diseases most sensitive to climatic change in... more Background Malaria is one of the major vector-borne diseases most sensitive to climatic change in West Africa. The prevention and reduction of malaria are very difficult in Benin due to poverty, economic insatiability the non-control of environmental determinants. This study aims to develop an intelligent outbreak malaria early warning model driven by monthly time series climatic variables in the Northern part of Benin. Methods Climate data from nine rain gauge stations and malaria incidence data from 2009 to 2021 were extracted respectively from the National Meteorological Agency (METEO) and the Ministry of Health of Benin. Projected relative humidity and temperature were obtained from the coordinated regional downscaling experiment (CORDEX) simulations of the Rossby Centre Regional Atmospheric regional climate model(RCA4). A structural equation model was employed to determine the effects of climatic variables on malaria incidence. We developed an intelligent malaria early warning ...

Water Science & Technology, 2012

Two caseins labelled as CaSMG (casein without fats) and CaMG (casein with fats) were extracted fr... more Two caseins labelled as CaSMG (casein without fats) and CaMG (casein with fats) were extracted from coconut cream. Both caseins were used as coagulants for the aggregation of humic acid (HA) particles in synthetic water at pH ¼ 6 during the jar-test essays. The optimum dosage of CaMG or CaSMG and the residual turbidities of treated water obtained depend on the type of used casein (CaMG or CaSMG) and the concentration of particles in solution. The optimal doses of CaMG and CaSMG are respectively 280 and 180 mg/L for solution S 1 (HA aqueous solution at 15 mg/L), and then 340 and 240 mg/L for solution S 2 (HA aqueous solution at 25 mg/L). The residual turbidities of treated water are respectively 6.88 and 3.85 NTU for solution S 1 and 4.52 and 2.53 NTU for solution S 2. The collected sediment volumes are respectively 1.2 and 1.5 mL for solutions S 1 and S 2. The electrophoretic mobility measurement and transmission electron microscopy images of flocs formed during the flocculation essays suggest that both caseins operate through both mechanisms (charge neutralisation and bridging process mechanism), this last one seems to be predominant. The aggregates formed are the large clusters and result from adsorption of HA particles by the casein molecules.

International Journal of Chemical Studies, 2019

Natural Resources, 2021

The waste management is a major environmental challenge in all the countries. In the Republic of ... more The waste management is a major environmental challenge in all the countries. In the Republic of Benin, in absence of controlled landfill, the wetlands are filling in by solid household waste to set up housing environments. This study aimed at identifying the various forms of wetlands water pollutions originated by this practice. Physico-chemical parameters of sampling water were determined by using Ionic chromatography and spectrometry of atomic absorption. The microorganisms indicating fecal peril were identified by the conventional techniques of microbiology. Water quality of a witness well was also used to assess the general water quality of the backfilled wetland. The results revealed the water samples collected from backefilled wetlands were mineralized (898.32 ± 6.13 μs/cm), rich in chlorinate (237.80 ± 4.23 mg/L) and nitrates ions (224.10 ± 3.42 mg/L). They are more colored (399.23 ± 3.01 Pt/Co) and more turbid (62.5 ± 2.48 NTU) than those of the unfilled wetlands. The resul...

The protection of aquatics ecosystems leads to the biological equilibrium which secures the safe ... more The protection of aquatics ecosystems leads to the biological equilibrium which secures the safe foods from the aquatics products. Toho Lake located to the southeastern of Benin is threatened by human pollution due to the chemical fertilizers, waste housekeeper, and both human and animal excrement result agglomeration. The aim of the present study is to Toho lake protection against chemical and bacteriological pollution of these wet ecosystems. Samples of water and sediment were collected and analyzed by HACH DR 3900 after undergone treatment The different analysis results revealed mean oxygenation of water (4,95mgo2/l), the Biochemical Oxygen Demand (21.5 mgo2/l), the Chemical Oxygen Demand (149, 39 mg/l) with the azote in Nitrate (NO3:0,18mg/l), ammoniacal azote (N-NH4:0,47mg/l) phosphorous (2,06mg/l) are very high. The lake is also polluted by fecal matters. The high contents of heavy metals in the sediment show that the sediments of the lake are polluted by the zinc (340mg/kg), ...

The presence of a high level of organic matter in solid household waste is a positive criterion f... more The presence of a high level of organic matter in solid household waste is a positive criterion for considering waste recovery through composting. This research aimed at studying of the impact of the fermentable fraction of municipal solid waste during composting. Five (5) mixtures have been developed and in each of the treatments, the added fermentable fraction represents 25 or 50% of the removed fraction. The temperature, Total Organic Carbon, nitrogen and pH values of each treatment were determined during the maturation process of the compost manufacturing trials according to the different constituents. Results revealed a strong positive correlation (r= 0.8566) between the total organic carbon and the fraction of total organic matter in the mixtures submitted to composting. From the analysis of the compost treatments carried out, it appears that the inputs of the T50v treatment (treatment obtained by substituting 50% of vegetable matter with the fermentable fraction of the MSW) a...

International Journal of Innovation and Applied Studies, 2015

American Journal of Applied Chemistry, 2020

In this study, the activated carbon (AC) was prepared from phosphoric acid activation of peanut s... more In this study, the activated carbon (AC) was prepared from phosphoric acid activation of peanut shell and used as adsorbent for atrazine removal from aqueous solutions. The prepared AC was characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) techniques. The effect of parameters such as solution pH, contact time, adsorbent dosage and concentration of atrazine solution were studied on adsorption process. The results of characteristics study shown that the surface of AC was porous with numerous functional groups. The kinetic results revealed that the adsorption process was well described by the pseudo-second-order model than the pseudo-first-order model. The intraparticle diffusion model involved in the adsorption process by multi steps. The equilibrium data were in the best agreement with the Langmuir model than the Freundlich and the Temkin models. The maximum adsorption capacities calculated according to the Langmuir isotherm were 66.66, 52.63 and 48.08 mg g-1 at 30°C and at pH 5, 7 and 9 respectively. The results of this study pointed out that the activated carbon prepared from the peanut shell has strong adsorption potential toward the atrazine herbicide, hence, it could be used for efficient adsorption of pesticide residues and other hazardous pollutants from wastewater.

Journal of Geoscience and Environment Protection, 2020

The protection of aquatic ecosystems is of great importance to maintain the biological balance ne... more The protection of aquatic ecosystems is of great importance to maintain the biological balance necessary to secure healthy foods therein imbedded. Toho Lake, located to the south east of Benin, is threatened by pollution emanating from anthropogenic activities with the use of chemical fertilizers, effluent of domestic waste, particularly human and animal excrement with neighbourhood effluents. This study aimed at assessing some heavy metals in fresh fish (Oreochromis aureus) of Toho Lake in order to secure healthy food for the population and protect the ecosystem. Samples of water and fishes were collected and analyzed by HACH DR 3900 after treatment. Results revealed a mean oxygenation of water (4.95 mgo 2 /l), Biochemical Oxygen Demand (21.5 mgo 2 /l), Chemical oxygen Demand (149, 39 mg/l) with the nitrogen in Nitrate (NO 3 : 0.18 mg/l), ammonium nitrate (N-NH + 4 : 0.47 mg/l), and phosphorous (2.06 mg/l) to be very high. The highest contents of heavy metals obtained in the fresh fish were cadmium (32.25 mg/kg), copper (115 mg/kg), lead (8.25 mg/kg), and zinc (90.75 mg/kg) and revealed that the fishes of Toho lake were polluted. The finding allowed us to conclude that the pollution of the lake and the fish carnage are due to anthropogenic pollution through chemicals spilling. Some protection methods of the lake and ecosystem are proposed in order to keep the fish safe and protect the well-being of the population.

International Journal of Biological and Chemical Sciences, 2016

Dans le but d'établir la corrélation entre les résultats des lixiviats du LES et ceux des eaux so... more Dans le but d'établir la corrélation entre les résultats des lixiviats du LES et ceux des eaux souterraines (puits et piézos) et de surface (lac), des analyses en composantes principales et factorielles ont été réalisées. Ces analyses permettent d'avoir une vue mathématique exacte de la répartition des points correspondants aux prélèvements dans l'espace défini par les facteurs qui sont les éléments analysés. L'analyse en composante principale des paramètres physico-chimiques et microbiologiques des deux premiers axes de la corrélation explique à 68,19% la variabilité du niveau des paramètres physico-chimiques et à 75,88% celle liée à la concentration en microorganismes dans les eaux de tous les points échantillonnés autour des lixiviats. La relation entre les paramètres étudiés des différents points échantillonnés avec les lixiviats, par rapport à la qualité de l'eau, a été aussi examinée à l'aide d'une analyse factorielle des correspondances simples. Les résultats obtenus montrent que les deux premiers axes de la corrélation expliquent à 95, 67% toute la variabilité des paramètres de qualité de l'eau au niveau des stations.

International Journal of Biological and Chemical Sciences, 2013

Dans cette étude, les échantillons d'eau de la retenue d'Okpara à Parakou ont été traités par les... more Dans cette étude, les échantillons d'eau de la retenue d'Okpara à Parakou ont été traités par les extraits aqueux des graines de Moringa oleifera en vue de réduire les concentrations de fer et de manganèse qu'ils contenaient. Dans deux échantillons d'eau de la retenue dont les concentrations en fer sont 8,20 mg/L et 21,10 mg/L puis 0,90 mg/L et 1,60 mg/L de manganèse, les taux d'abattement aux doses optimales 64 mg/L et 48 mg/L de Moringa oleifera sont respectivement de 80% et 42% pour le fer et 77% et 45% pour le manganèse. Lorsque Moringa a été utilisé comme adjuvant de coagulation au sulfate d'aluminium, 94% de fer et 90% de manganèse ont été éliminés. Ces résultats montrent que la combinaison de Moringa oleifera avec le sulfate d'aluminium conduit à des taux d'abattement de fer et de manganèse meilleurs que ceux obtenus avec le sulfate d'aluminium ou le Moringa oleifera utilisé chacun comme coagulant primaire ; en outre, cette combinaison a l'avantage de réduire la quantité d'alun nécessaire et par conséquent le coût du traitement de l'eau brute diminue.

Journal of Environmental Protection, 2011

Identification of waste characteristics is an important step towards improving waste recovery. Th... more Identification of waste characteristics is an important step towards improving waste recovery. The aim of this research was to determine the physical and physico-chemical characteristics of waste of Abomey-Calavi city and to study the relationship between standard of living and average ratio of daily waste generated by each person. In this study the methodology used French standards to characterize particle size and typology of solid waste generated by the population of Calavi City in Benin, West Africa. According to home criteria, the study area was stratified into three distinct levels of standard of living called: high standing, medium standing and low standing; Waste from 60 households was weighed daily. The total waste produced by each household was collected seven (7) days a week, for a period of three weeks. Waste characterization was performed using ratio, size granulometry and typological composition. Physico-Chemical analysis including organic mater, pH, Total Organic Carbon, total Kjeldahl nitrogen and metal trace element were also performed. To better assess waste compostability, water extractable organic matter was quantified and qualitative identification was made with XAD8 and XAD4 resins. Results show that the amount of waste increases with the standard of living; the average ratio of daily waste generated is 0.89 kg•day-1 •person-1. Independently of the standard of living, fermentable compounds represent the largest proportion of waste materials (45%). Qualitative difference of waste content in organic matter is shown as a function of the population's living standards. These results could be explained by a higher consumption of meat in the households with a higher standard of living, reflecting a greater proportion of transphilic (TPI), and hydrophilic (HPI) fractions. The C/N ratio is lower in the high standing households than in low ones. Metal trace element analysis showed a low but still significant pollution, whereas high iron and aluminum concentrations were found in all standings. In conclusion we propose a strategy for waste management in Abomey-Calavi based on sorting at the source to eliminate plastic waste and valorization of wastes via composting.

Journal of Applied Biosciences, 2013

Étude de la Cinétique d'adsorption des molécules anti paludéennes par les résines

International Journal of Biological and Chemical Sciences, 2011

RESUME L'objectif de cette étude est de mettre au point un système efficace de production de la v... more RESUME L'objectif de cette étude est de mettre au point un système efficace de production de la vapeur alimentaire adapté aux conditions techniques et financières dans les entreprises des pays en voie de développement. A la SOBEBRA, le système de production est alimenté par l'eau de distribution et utilise un traitement externe (adoucissement par échange d'ions) et un traitement interne mixte qui se fait par la coagulation et par la dispersion. La vapeur est produite par une chaudière à tube alimentée par l'eau d'appoint et l'eau du retour condensât. Des échantillons sont prélevés aux différents points critiques de la chaîne de production afin de vérifier l'efficacité des traitements. Les résultats des analyses ont révélé que la dureté de l'eau d'appoint est stable et nulle. L'alcalinité est élevée dans la chaudière avec une valeur moyenne de pH 12. Le titre alcalimétrique (TA) et le titre alcalimétrique complet (TAC) sont aussi maintenus élevés dans la chaudière avec des valeurs moyennes respectives de 90 o F et 120 o F. Dans la chaudière on note également l'augmentation des teneurs en phosphate et en silicate qui atteignent respectivement 400 mg/L et 59 mg/L. Le dispositif de production satisfait aux normes internationales 3A. Le retour condensât est parfois contaminé par les opérations de lavage des bouteilles dans le terminal des opérations.

Annales des Sciences Agronomiques, 2011

L’objectif de cette étude est d’évaluer l’efficacité d’un système de traitement de l’eau de distr... more L’objectif de cette étude est d’évaluer l’efficacité d’un système de traitement de l’eau de distribution adapté aux conditions financières et techniques des entreprises agroalimentaires du Bénin. A la SOBEBRA, l’eau de distribution (eau de la société nationale des eaux du Bénin) est traitée par un système mixte en trois temps : la désinfection par le chlore, la floculation-coagulation-décantation par le sulfate d’aluminium et la filtration avec un filtre à sable et un filtre à charbon actif. Les résultats des analyses physico-chimiques ont révélé que l’eau traitée (eau de process) est plus stable que l’eau de distribution. La turbidité de l’eau traitée est en moyenne 0,1 NTU ; la teneur en chlore libre, en chlore totale et en aluminium est 0,0 mg/L ; le TAC, le TH, le pH, et la conductivité sont régulés et maintenus à des valeurs recommandées par les normes internationales. Les analyses microbiologiques de l’eau traitée révèlent une absence totale des coliformes totaux et Escherichia coli, des streptocoques fécaux et des spores de Clostridium sulfito-réducteurs.Mots clés : eau de process, coagulation-floculation-décantation, filtre à sable, filtre àcharbon actif