LARHYSS Journal

10

Authors: ABDOULAYE DEMBA N’DIAYE, MOHAMED OULD SID’ AHMED OULD KANKOU

The study assessed the microbiological and physicochemical parameters of wastewater collected between October 2011 and September 2012 from the effluent of the WWTP in vegetable farming area of Sebkha in Nouakchott. The results of physicochemical analysis presented in this work have shown those the values of pH varied from 7.3 to 8. The EC values of experimental samples varied from 1050 to 1650 μS/cm. The turbidity values of experimental samples varied from 26.5 to 51.2 NTU. Effluents from the WWTP are characterized by a maximum iron and manganese content respectively of 412 µg/L and 22 µg/L and a minimum of 210 µg/L and 4 µg/L. Effluents from the WWTP are characterized by a maximum ammonia and orthophosphates content respectively of 120 mg/L and 60 mg/L and a minimum of 10 mg/L and 13.8 mg/L. The values of COD recorded at the WWTP effluent ranged from 25 mg/L and 75 mg/L. The microbiological results show that the microbial load of fecal coliforms and fecal streptococci is very important. The levels of fecal coliforms and fecal streptococci ranged respectively between 3.103 to 8.103 CFU/100 mL and from 5.103 to 9.103 CFU/100 mL. The microbiological analysis revealed high concentrations of faecal coliforms and faecal streptococci, values exceeding the microbiological standards of the WHO. The application of Principal Component Analysis indicates that two groups of wastewater: a group of wastewater turbid characterized by a mineral salt, some metals and organic and inorganic matter expressed by COD and a group of wastewater consists of very high levels of fecal loads, ammonium and phosphates.

12

Authors: YOUCEF L., OUAKOUAK A., BOULANOUAR D., ACHOUR S.

The aim of this study is to test the efficiency of removal of phosphate in natural waters by adsorption on powdered activated carbon (PAC). The treated solutions are synthetic phosphate solutions in distilled water and ground waters in the region of Biskra. Phosphate adsorption tests have shown that the retention of phosphate on the PAC is a reversible phenomenon. The equilibrium time is less in mineralized water (30 seconds) then in distilled water (3 hours). Removal rate are improved with the increase of the dose of the adsorbent (0,1 to 4 g/l). Adsorption of phosphate follows the two models of Langmuir and Freundlich. The process is influenced by the pH of treatment. In synthetic solutions of distilled water, removal rate decrease with the increase of the initial phosphate content (1 to 20 mg/l) in contrast in synthetic solutions of mineralized water the opposite occurs. This is a result of unlike the removal mechanisms of phosphate in the two media of different mineralization.

13

Authors: ZOUGGAGHE F., MOUNI L., TAFER M.

The objectif of this study is to draw a map of quality or health of the river system watershed of Soummam by using standard global biological index (IBGN) of AFNOR (1992) and identify the most degraded sections of the watershed. The assessment of the biological quality is based on the general principle according to which each type of natural environment has its own characteristics community of organisms. Any degradation of the natural organisms indicates that some disturbance has occurred. Benthic invertebrate community were sampled on three areas of watershed of Soummam, in a total of 34 stations were sampled between 20m and 1100m of altitude between 2004 and 2010. The environmental quality is good in 5.9% of the stations where the index IBGN values displays 13 and 14, which meant that is not far from the fair quality, since these values are located just to the boundary between good and fair quality. A fair biological quality in 26.5% of stations, a bad quality in 52.9% of stations and finally, a very poor quality in 14.7% of the stations.

14

Authors: DIALLO A.D., IBNO NAMR K., N’DIAYE A.D., GARMES H., KANKOU M., WANE O.

In order to better understand and manage the quality of surface water, is often undertaking long and tedious analysis campaigns. These usually generate enough data whose interpretation is not always easy. Application of Principal Component Analysis (PCA) for such a task could be beneficial . It is in the context of such an application as 26 physico-chemical parameters: The potential hydrogen (pH) , electrical conductivity (EC), total dissolved solids (TDS), temperature (T°), turbidity (Turb) Total Hardness (TH), bicarbonate (HCO3-), sulfate (SO42-), nitrate (NO3-), nitrite (NO2-), chloride (Cl-), orthophosphate (PO43-), sodium (Na+), potassium (K+), magnesium (Mg2+), calcium (Ca2+), oxidizability permanganate (MO) , aluminum (Al) , ammonium (NH4+), silica (SiO2), zinc (Zn), lead (Pb), copper (Cu), manganese (Mn), iron (Fe) and fluorine (F-), derived from the analysis of water samples collected during the months of June, July, August and September 2012, of eight (8) locations at the right bank of the Senegal River. This study shows that it is possible, with a view to creating a management tool to simplify the model initially constructed from 26 variables to bring it to the extent of one variable whose turbidity relatively simple and less expensive. This reduction is even more interesting that the variable is to consider measurement is simple. In view of the creation of management tools, this tool looks like a good alternative. In the area of quality control the turbidimetry prove essential analytical tools in the treatment of water like the pH-metry, the conductimetry and the colorimetry.

18

Authors: NANFACK N.A. CARINE, FONTEH F. ANYANGWE, VINCENT K. PAYNE, KATTE BRIDGET, FOGOH J. MUAFOR

This paper looks at the quality of non-conventional waters and their effects on the health of consumers in seven (07) quarters deprived of conventional water network in Mbouda, West Cameroon. Sociological techniques were used to obtain data on water sources, existing types of waterborne diseases in households, the nature of hygiene and sanitation of the water points and the treatment provided to these drinks water before consumption. The number of cases of various waterborne diseases recorded in hospitals in the town from January 2012 to February 2013 was also verified. Water samples were collected from 4 wells, 4 springs and 2 boreholes in December 2012 and March 2013 for analyzes using the techniques of counting bacteria on liquid and solid medium. Results of this study shows that water from non-conventional sources are contains high levels of pathogenic microorganisms, such as fecal streptococci, Salmonella, fecal coliforms and Proteus sp. The consumption of these waters exposes consumers to serious health risks, thus requiring appropriate treatment before consumption.

20

Authors: N’GUESSAN KOUAMÉ A., KOUASSI AMANI M., GNABOA R., TRAORÉ K.S, HOUENOU P.V.

This study focuses on the analysis of hydrological phenomena causing pollution landscaped lakes of Yamoussoukro city (Center of Ivory Coast). The methodology takes into account the analysis of climate variability (Pettitt test and graphical representation), water balance (Coutagne method, of Thornthwaite method and Tixeront-Berkaloff method) and comparative analysis using from potential evapotranspiration and real evapotranspiration on a monthly time. The results of this study were used to characterize the main manifestations of climate variability (1975-2009) observed for more than three decades in the region of Yamoussoukro. It appears from the study of the conditions of prolonged rainfall deficits have been identified before 1992. The post-1992 is characterized by a resumption of rainfall without reaching the heights of rainfall before 1970. Climate variability is manifested by a monotonic increase of air temperature. The water balance shows that the region receives an average of 1137 mm of rain annually and real evapotranspiration (ETR) is 853 mm, or about 74.98 % of the height of precipitated water. The infiltrated water slide is in the order of 70 mm or 6.15% of the height of precipitated water. The amount of runoff is in the order of 215 mm, or 18.87% of the height of precipitated water. The change observed on the cumulative heights rainfall was accompanied by a change in the duration of the rainy season. A trend towards shorter rainy seasons is demonstrated in the region of Yamoussoukro.

23

Authors: ALALI A., BENMOHAMMADI A., BOUDAD L., AQID N.

The descriptive study of dune facies plain Tafilalet enlightened us on the likely sand sheets, the axis of advance of the sands, and any remobilisassions. Only a more detailed analysis will shed light on the behavior of particles during transport, according to their size or nature of their origin, their specific areas of migration, deposition and remobilization. This characterization of the sand through his elementary particle, will be by laboratory analyzed by granulometric by sieving, morphoscopic by observing the insoluble fraction and mineral by separating the soluble fraction and heavy mineral Identification