Radiometric interpretation of geologic data and its effect on groundwater in Abuja, North-Central Nigeria

The purpose of this study is to evaluate the quality of groundwater in different locations for water consumption at Dei-Dei, Kubwa, Gosa and Lugbe area of Abuja, North-Central Nigeria. Vertical electric sounding and shuttle radar topography mission was used to determine the depth of groundwater bearing formation and map lineaments structures underlying the area. Boreholes with the geophysical log data were drilled and rock samples in each layer lithologically were collected for ?-ray analysis. The activity concentrations of 238U, 232Th, and 40K from the borehole rock samples were determined using high-purity germanium ?-detector. The activity concentration of radionuclides in Dei-Dei borehole has a mean value of 30.1 ± 2.9 Bq kg?1 for 238U; 67.2 ± 5.2 Bq kg?1 for 232Th, and 832.3 ± 105.0 Bq kg?1 for 40K. Kubwa borehole has a mean value of 34.4 ± 3.2 Bq kg?1 for 238U; 60.5 ± 5.4 Bq kg?1 for 232Th and 573.1± 72.0 Bq kg?1 for 40K. At Gosa borehole, 238U has a mean value of 26.1 ± 2.5 Bq kg?1, 62.8 ± 4.8 Bq kg?1 for 232Th and 573.3 ± 73.0 Bq kg?1 for 40K. At Lugbe borehole 238U has a mean value of 20.0 ± 2.0 Bq kg?1, 46.8 ± 4.9 Bq kg?1 for 232Th and 915.2 ± 116.1 Bq kg?1for 40K . Significantly higher concentration of 238U and 232Th occurred in samples collected from Dei-Dei borehole was attributed to granitic intrusions produced by denudation and tectonism. Inductively coupled plasma mass spectrometry (ICP-MS) was used to determine the concentrations of 238U and toxic elements (i.e. Pb, Cr, Cd, Zn, Ni, As and Mg) in water samples collected from the boreholes and public water supply in the study area. The activity concentration of 238U in groundwater-based drinking was noted higher at Lugbe borehole with a value of 2736 µBq L?1 when compared with other boreholes. In the study area, the inhabitants permanently used water from the boreholes for daily drinking and household requirements. The annual effective dose was estimated to be in the range from 1.46 x 10-5 to 9.03 x 10?5 mSv yr?1 for boreholes with the highest value noted in Lugbe borehole with a value of 9.03 x 10?5 mSv yr?1. The group receives about 5.55 x 10?5 mSv of the annual collective effective dose in the study area due to 238U in drinking water. The highest radiological risks for cancer mortality and morbidity were found to be low, with highest values of 1.03 × 10?7 and 1.57 × 10?7 obtained from Lugbe borehole. The chemical toxicity risk of 238U in drinking water over a life time consumption has a mean value of 4.0 x 10?3 µg kg?1 day?1 with highest value of 6.0 x 10?3 µg kg?1 day?1 obtained from Dei-Dei and Lugbe boreholes. The elemental concentration of Pb was noted to be higher than the recommended permissible limit at Lugbe borehole and Public Nigeria Water Board with values of 0.014 and 0.012 mg L?1 , respectively. Other results obtained were below the recommended acceptable level by World Health Organization and United State Environmental Protection Agency. Results of the measurements could be of importance in radio-epidemiological assessment, diagnosis and prognosis of uranium induced cancer in the population of the inhabitants of Abuja

Geophysical Analysis of Basement Terrain Groundwater Using Vertical Electrical Sounding: A Case Study of Parts of Abuja North Central Nigeria

The successful exploitation of groundwater requires a proper understanding of the hydrogeological characteristics of the sub-surface aquifers found within the basement complex. This can be carried out using various geophysical survey methods. Groundwater occurs in the joints, fissures, fractures, shear zones and weathered overburden of un-weathered rocks. Therefore effective groundwater development requires careful geophysical analysis and interpretation of data. The use of vertical electrical sounding (VES) for groundwater (hydrogeological) exploration is popular in the basement complex rocks and sedimentary basins. This study was aimed at analysing the hydro geological characteristics such as bedrock depth, lithological units and degree of fracturing and drilling location of groundwater in the basement complex / terrain of Garki, Kurudu, Dei-Dei and Kubwa areas of Abuja, North central Nigeria using Resistivity Method. Finally, the results indicate that the choice of geophysical survey method determined by physical properties of the area; influence groundwater availability, susceptibility and supply

Geophysical Analysis of Basement Terrain Groundwater Using Vertical Electrical Sounding: A Case Study of Parts of Abuja North Central Nigeria

The successful exploitation of groundwater requires a proper understanding of the hydrogeological characteristics of the sub-surface aquifers found within the basement complex. This can be carried out using various geophysical survey methods. Groundwater occurs in the joints, fissures, fractures, shear zones and weathered overburden of un-weathered rocks. Therefore effective groundwater development requires careful geophysical analysis and interpretation of data. The use of vertical electrical sounding (VES) for groundwater (hydrogeological) exploration is popular in the basement complex rocks and sedimentary basins. This study was aimed at analysing the hydro geological characteristics such as bedrock depth, lithological units and degree of fracturing and drilling location of groundwater in the basement complex / terrain of Garki, Kurudu, Dei-Dei and Kubwa areas of Abuja, North central Nigeria using Resistivity Method. Finally, the results indicate that the choice of geophysical survey method determined by physical properties of the area; influence groundwater availability, susceptibility and supply

2-1/2 Dimensional Modeling of the Major Structures Underlying Dong and Shelleng of the Upper Benue Valley, Using GM-SYS Computer Modeling

Airborne magnetic data over part of Dong and Shelleng area of the upper Benue Valley, N-E basement complex of Nigeria's was carried out to investigate the deep and thick structures of the underlying geology and their relationship with granitic intrusion. These features are interpreted in terms of deep geologic structures, and/or susceptibility variations within basement rocks. The residual separation exercise revealed the area is underlain by a NE-SW regional trends, which shows it is in agreement with Benue trough, presumed they have the same structure control. Furthermore, the 3-D residual magnetic anomaly map suggests Dong is likely to be the sedimentary basin. It shows that the magnetic field there is smoother, which is masked off by the effects of the stronger magnetic basement. High amplitude of the anomalies which outcrop at eastern part of Dong where the profile cut across 6 could be the presence of Ngurore basalts. The thickness revealed by the model (DD 1), Northwestern part Numan has a maximum thickness of 1.4km and minimum of 0.2km. In D-D1 modeling, it revealed a porphyritic granite with non- uniform thickness of about 1.1Km and minimum of 0.17Km with a width approximately 2.9Km. The first sedimentary layer reveals has a thickness of about 1.0Km and the second varies from 1.0 to 1.6km thick. The width is about 4km.The Alluvium thickness increases progressively between 0.2Km to 0.7Km and the width of about 18km, reveals by the model. The thickness of the basin varies between 0.9km to 2.9Km. The model reveals the width of the basin to about 136Km

PREDICTING DEGRADATION WITH BIOCHEMICAL OXYGEN DEMAND IN DISINFECTANT-POLLUTED SEWAGE

Most households frequently make use of disinfectants to annihilate infectious bacteria present in toilets and bathrooms. Unfortunately, some of these bacteria may be required for the degradation of sewage in the septic tank system (STS). This paper investigates how the performance (degradation capacity) of sewage will be affected by the inharmonious addition of disinfectants with biochemical oxygen demand (BOD) as the predictor. With a clean 50-litre container, a sewage sample was collected from a waste stabilization pond situated in a Nigerian Tertiary University, transported to the sanitary laboratory in the Department of Civil Engineering, University of Nigeria, Nsukka, and poured into five 4-litre white containers. Different doses of disinfectants – 0.5 ml, 1 ml, 1.5 ml, 2 ml, and 2.5 ml, were simultaneously added only at the initial day of experimental setup under aerobic conditions, and the pH, dissolved oxygen (DO), disinfectant dose, chemical oxygen demand (COD), and BOD were measured every three days for three weeks. Multivariate analysis was performed on the explanatory variable – pH, DO, disinfectant dosage, and COD – using e-Views 8.0, which revealed that the continuous addition of disinfectants to sewage inhibits its degradation, thereby resulting in increased organic loading within the STS, and may further lead to septic tank failure due to shock loading and a major source of ground water been polluted with emerging contaminants

Carcinogenic Risk of Arsenic (As) in Groundwater and Bottled Water Samples in Covenant University and Canaanland, Ota, Ogun State, Nigeria

This study was conducted in order to estimate the carcinogenic risk of heavy metals exposure via the consumption of groundwater and bottled water for the population of Covenant University and Canaanland, Ota, Ogun state using Perkin Elmer Optima 8000 ICP-OES. The chronic daily intake (CDI) in all the samples ranged from 0.005 and and 0.014¹gL¡1kg¡1d¡1which was found to be negligible of potential risk on the inhabitants of different age groups. The carcinogenic Risk (R) for all the samples ranged between 0.01 and 0.025 ¹gL¡1d¡1. The R for all the age groups was found to be less than the acceptable level of EPA. The highest carcinogenic risk in Arsenic was found in children, which could be attributed to their lower body weight. However, all the values measured were observed to be below the recommended level by USEPA and WHO respectively