RESUMEDans le cadre du suivi de la qualité des eaux de surface destinées à la potabilisation, l'évolution des éléments précurseurs d'eutrophisation (matières azotées et phosphorées) du barrage n°3 de Ouagadougou a été investiguée durant la période de septembre 2012 à décembre 2012. Les paramètres chimiques ont été déterminés par spectrophotométrie d'absorption moléculaire et les paramètres physiques par la méthode électrochimique. Les analyses physicochimiques ont mis en évidence des corrélations entre la teneur en nitrates et la chlorophylle A (r = 0,715) et entre la température et la chlorophylle A (r = 0,838). La teneur en orthophosphte est faiblement corrélée avec la teneur en chlorophylle A du barrage (r = 0,171). Il n'a été observé aucune différence significative entre les concentrations en orthophosphates des quatre mois de la période d'étude (p<0,05). La plus forte valeur (1,3 mg/l) a été observée au cours du mois de septembre et la plus faible valeur (0,14 mg/l) au cours du mois de novembre. Cependant, les teneurs en nitrates, température et chlorophylle A des eaux étaient plus fortes au cours du mois d'octobre (respectivement, 6,6 mg/l; 29,14 °C ; 0,04 µg/l) et plus faibles en décembre (respectivement, 3 mg/l ; 23,25 °C ; 0,02 µg/l). Ces résultats indiquent que les mois d'octobre et novembre sont des périodes à risque d'eutrophisation du barrage n°3 de Ouagadougou. Il ressort des résultats que l'eau du barrage est de bonne qualité au plan physico-chimique et revêt un état trophique oligo-mésotrophe. © 2016 International Formulae Group. All rights reserved. Mots clés :Eutrophisation, chlorophylle A, état trophique, nitrates, température, barrage n°3 de Ouagadougou. Study of eutrophication's precursors items of Ouagadougou's 3 rd dam's waters, Burkina FasoF. W-b. TAPSOBA et al. / Int. J. Biol. Chem. Sci. 10(2): 846-859, 2016 847 ABSTRACTIn a framework of monitoring the quality of surface water intended for drinking, the evolution of eutrophication's precursors (nitrogenous substances and phosphorus) of Ouagadougou's third (rd) dam has been done in the standard base period from September 2012 to December 2012. The chemical measures have been determined by molecular absorption spectrophotometry method and the physical parameters by electrochemical method. The physicochemical tests underlined interrelated the relationship between nitrate content and the chlorophyll A (=0.715) and between the temperature and chlorophyll A (r=0.838).The content of orthophosphates is feebly correlative with the chlorophyll A content of dam (r=0.171). Any significant distinction hasn't been observed between the orthophosphates' mergers of four months' studying (p=0.05).The strongest value ( 1.3 mg /l) has been checked in the course of the month of September and the weakest value ( 0.14 mg/l) during the month of November. Meanwhile, the nitrate's content, temperature and chlorophyll A of waters were strongest in the course of October (respectively, 6.6 mg /l ; 29.14 °C ; 0.4 ug /l) and lowest in December ( respectively, 3 mg/...

Human health risks assessment were estimated by determining the nature and probability of adverse health effects in the North region’s populations who are now exposed to arsenic from drinking water or will be exposed in the future. Several questions were addressed in this study: what types of health problems may be caused by arsenic from drinking water? What is the chance that people will experience health problems when exposed to different levels of arsenic? What arsenic level are people exposed to and for how long? To answers these questions we have first identified the hazard by evaluating arsenic concentration in thirty-four (34) bore-hole water points among the region based on the assumption of clinical cases related to drinking water. Arsenic concentration ranged from 0 up to 87.8 micrograms per liter. Next we assessed the dose-response of exposure to arsenic. Dose-response relationship describes how the likelihood and severity of adverse health effects are related to the amount and condition of exposure to arsenic. This required us to choose toxicity reference values (TRVs) above which adverse effects may occur for noncarcinogenic and for carcinogenic effects. Exposure factors have been calculated in two scenarios: people from 0 to 14 years old and people from 15 to 70 years. Exposure has been estimated indirectly through consideration of measured concentrations of arsenic in drinking water. This study show that people in the Yatenga, Zondoma and Passore provinces are at very high risk for developing several pathologies such as hyper pigmentation, keratosis, cancer, etc. due by chronic exposure to arsenic in drinking water.

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The use of aluminum sulphate in clarifying raw waters raises many concerns about its impact on human health. Thus, the present study was initiated to compare the effects of Moringa oleifera and aluminum sulphate besides evaluating the association between M. oleifera or aluminum sulphate with Opuntia ficus-indica or syntofloc for water treatment. The essays were carried in Jar Test using waters of 352.80 Nephelometric Turbidity Units (NTU). The monitoring of different physico-chemical and microbiological parameters at different doses and after different decanting time was used to determine optimal conditions and evaluate the effectiveness of treatment. The results showed that it took fewer doses and less decanting time for aluminum sulphate than moringa to obtain the same residual turbidity. The use of 0.9 g/L of moringa removed 99% of turbidity after 12 h of decanting. Successive use of moringa (0.9 g/L) with O. ficus-indica extract (0.6 ml) reduced the decanting time to 15 min. However, this treatment eliminated only about 57% of total coliforms. The moringa/cactus association, although highly effective, remains less than the treatment based on aluminum sulphate and synthofloc. This "organic" association is nevertheless an ideal alternative because of its great capacities that could be further optimized.

L’eau potable, un aliment de base et son accès est l’un des besoins humains fondamentaux. A Ouagadougou, l’eau potable provient du traitement des eaux de surface à Paspanga et à Ziga. Les remontées de boues constituent un phénomène persistant dans les processus de traitement de l’eau à Paspanga. L’objectif de ce travail était de trouver les causes de ce phénomène afin d’optimiser les coûts et taux de production d’eau potable. Pour ce faire, les paramètres physico-chimiques et des essais de traitements de l’eau brute ont été réalisés selon les normes de qualité. Les résultats ont montré que l’eau est potabilisable. En effet, la turbidité, la teneur en matière en suspension et en matière organique sont respectivement en moyenne 116,52 NTU, 10,85 mg/l, 4,72 mg/l d’O2 en mai et 719,13 NTU, 21,07 mg/l, 13,08 mg/l d’O2 de juin à juillet. Le pH de l’eau en mai est faible et en moyenne 6,89 et 7,50 dans les mois de juin à juillet. La mise en évidence de la production de gaz révèle que cette production est progressive. Les remontées de boues sont donc une résultante de deux facteurs : la qualité de l’eau brute et la production de gaz au fond des décanteurs. Mots clés : Décanteur, remontée de boue, traitement, eau   English title: Study of the phenomenon of mud increase on the lamellate decanter of the station of treatment of water of Paspanga in Burkina Faso Drinking water is a basic food and its access is one of the fundamental human needs. For Ouagadougou, it comes from the station of water treatment of surface at Paspanga and Ziga. The mud increase constitutes a persistent phenomenon in the treatments of water of Paspanga. The objective of this work was to find the causes of this phenomenon in order to optimize the costs and rate of drinking water production. To be done, the physicochemical parameters and the tests of rough water treatments were carried out according to standards of quality. The results showed that water is potabilisable. Indeed, the average of turbidity, content of organic matter and suspended matter of water were respectively 116,52 NTU, 10,85 mg/l, 4,72 mg/l of O2 in May and 719,13 NTU, 21,07 mg/l, 13,08 O2 mg/l from June to July. The pH of water varied to 6,89 in May; to 7.50 in June and July. In addition, the results showed that the gas production revealed is progressive over time, which would mean that the mud increased would be a result of two factors: the quality of raw water and the production of gas at the bottom of the decanters. Keywords: Decanter, rising mud, treatment, water