by Dial Niang, Amadou Keita, Chaim Vivien Doto and Hamma Yacouba
Original Research
This article deals with the spatio-temporal variability of actual evapotranspiration on sandy veneers in the Burkinabe Sahel characterized by a large variability of rainfall and exceptional dry conditions according to the seasons. In order to establish a water balance, a tensio-neutronic device was deployed on seven (07) sites located on three (03) surface states (Unprotected grazed area, Restored fenced area and Protected area). Results showed a difference in the behavior of the actual evapotranspiration during the drying phase on the different surface states. Indeed, the presence of superficial film (site S1) significantly limits water infiltration. On desiccation sites (S3, S5, S6 and S7) characterized by the scattered or abundant presence of vegetation, the absence of indurated superficial film creates more favorable conditions for infiltration which results in a more or less significant accumulation of water in the soil. As for the partially encrusted sites (S2 and S4), we observed an intermediate behavior with respect to the other two sites with more or less water storage in the soil.
American Journal of Water Resources. 2019, 7(4), 163-172. DOI: 10.12691/ajwr-7-4-5
Pub. Date: November 18, 2019
9222 Views1497 Downloads
by Obiewa James Oduor, Kariuki David Kinuthia and Damaris Nduta Wachira
Original Research
In this study, the pollution loading on Sosiani River, in Uasin Gishu County, Kenya, was assessed. The aim of this study was to determine assimilation of pollution loading by the two wastewater treatment plants located in the Eldoret Municipality. Samples were collected from six points along the river, influents and effluents of the treatment plants. Faecal and Total Coliforms, heavy metals; Pb, Cd, Cu and Zn, anions; Cl-, F-, NO3-, PO43- and SO42-, flow and pollution loading points, PLP, were determined. The parameters were determined using experimental procedures. The PLP was 800 and the river’s tolerance limit 10 %, hence a threshold of 880 PLP. Heavy metals’ levels were; Pb 0.583 - 0.970 mg / L, Cd 0.081 – 0.112 mg / L, Cu 0.038 - 0.105 mg / L and Zn 0.097 - 0.116 mg / L. Faecal and Total Coliforms were 25 - 1144 and 120 - 1555 Cfu / 100 ml, respectively. Chemical parameters were in the range; F 0.0125 - 0.469 mg / L, Cl 141.800 - 529.390 mg / L, NO3 2.990- 6.495 mg / L, PO4 0.038 - 4.052 mg / L and SO4 0.319 - 6.424 mg / L. The river flow range was 13920 - 70560 L / minute. The effluent flows were 1560 and 3960 L / minute. The coliforms exceeded the nil Cfu / 100 ml limit. Chloride levels at S2, S4, S6 and phosphate at S6 exceeded the 275 and 0.11 mg / L limits, respectively. The study will provide information on the contribution of the treatment plants to the pollution loading into the river. It will highlight the role of a river volume in determining its assimilative capacity and this will inform decisions made by water service providers on effluent volume.
American Journal of Water Resources. 2019, 7(4), 155-162. DOI: 10.12691/ajwr-7-4-4
Pub. Date: November 15, 2019
11274 Views1566 Downloads
by OO Falowo, AS Daramola and OO Ojo
Original Research
Hydrogeological properties measurements through pumping or slug test is an imperative method of determining the productivity of an aquifer for effective sustainability and development. Therefore groundwater potential evaluation using pumping test was carried out on thirty six boreholes, straddling different geologic units in Southern parts of Ondo State, Nigeria. This was done in order to estimate the transmissivity and hydraulic conductivity of the overburden aquifers. The pumping test involved a 1.0-hp submersible pump with a check valve and a 19-mm diameter discharge line. The static water levels measured range between 1.2 – 30.5 m, and an average of 11.9 m. The static water level was higher in sandstone derived aquifers than shale, granite, gneiss or migmatite, with an associated low drawdowns less than 2 m. The values of hydraulic conductivity estimated in the area vary from 0.0797 (Ile Oluji) to 65.2493 m/d (Ilaje/Ese Odo/Igbekebo), and an average of 6.25 m/d. The transmissivity values range between 1.6183 – 652.4928 m²/d. The recorded specific yield of the aquifers across the study area shows predominant range of 0 – 100 m³/d. This range of values generally indicate a non-prolific aquifers, as the mean value obtained is less than 200 m³/d required for domestic usage based on groundwater usage survey carried out in the study area. The findings of the study shows a fairly homogeneous hydraulic properties, except the southern part which is characterized by high yield capacity, transmissivity, hydraulic conductivity, and considerable aquifer thickness (greater than 25 m) with a steady/high drawdown. Consequently, favourable areas for future groundwater exploitation/development is the southern parts which embraced Erinje, Okitipupa, Ilaje/Ese Odo.
American Journal of Water Resources. 2019, 7(4), 146-154. DOI: 10.12691/ajwr-7-4-3
Pub. Date: October 22, 2019
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by B. Yorkor and Y. O. L. Momoh
Review Article
This paper presented an overview of different methods for nitrogen and phosphorus removal from wastewater effluents in Nigeria. Research data indicated that wastewater effluents in Nigeria contain high concentrations of nitrogen and phosphorus, which contributed to the eutrophication of many surface water bodies in the country. Study of wastewater characteristics in Nigeria showed that wastewater effluents in Nigeria contain an average of 650mg/l of total nitrogen, 120mg/l of total phosphate and 55,000mg/l of COD; nitrate-nitrogen and phosphorus ranged between 43mg/l and 56mg/l; ammonium nitrogen ranged between 52mg/l and 107mg/l; nitrate nitrogen from ranged 34.5mg/l and 58.5mg/l. The technologies and principles of anoxic treatment of wastewater are presented. The stoichiometry of nitrification and denitrification reactions are presented. State and Federal Ministry of Environment in Nigeria should enforce relevant regulations to ensure that wastewater effluents are treated to reduce nitrogen and phosphorus content to acceptable standards before discharge into watercourses.
American Journal of Water Resources. 2019, 7(4), 136-145. DOI: 10.12691/ajwr-7-4-2
Pub. Date: September 27, 2019
13262 Views1199 Downloads
by Ahmed Lachhab
Original Research
Water quality index (WQI) uses many weighted, measurable parameters to give one number that reflects the quality of the water. WQI is a standard approach to evaluate and compare results of different streams because of its concise form. The correct WQI expression for a specific stream can be challenging and requires a good stream water quality knowledge. In this study, five Penns Creek headwater streams located in the Bald Eagle State Forrest, PA were selected and assessed with five different Water Quality Indices and a new specific WQI expression was identified and implemented to simplify a water quality index value. The water quality data used for the five WQI and the specific WQI expressions was collected from the summer months of June and July from 2015 to 2017. Using these five different WQI expressions, revealed a range of values from 80 to 100 making these streams ranked between good and excellent quality. Since the WQI is meant for drinking water, the normalization factors of some parameters such as pH, temperature, and Biochemical Oxygen Demand (BOD5), are excessively lowered and limits the application on natural headwater streams, where some parameters should not be weighted. Using this experimental site that is known to have a good water quality, with little to no human impact, the WQI has been rearranged taking in consideration the following steps: 1) the range of the pH has been expanded to more acidic and basic water 2) the range of temperature lowered for colder water 3) excess parameters, like BOD5 and other ion concentration were removed.
American Journal of Water Resources. 2019, 7(4), 128-135. DOI: 10.12691/ajwr-7-4-1
Pub. Date: September 16, 2019
11774 Views1806 Downloads