International journal of environmental science and technology, Apr 21, 2024
The study was conducted in an old landfill in the Calabar South local government area of Cross Ri... more The study was conducted in an old landfill in the Calabar South local government area of Cross River State. The essence of the research work is to investigate groundwater quality within the area and evaluate the level of environmental pollution due to radioelement exposure to landfill waste. Ten profile (traverse) lines were created for the survey, and twenty vertical electrical soundings were probed with a maximum half-current electrode (AB/2) of 200 m. The result revealed four to five geoelectric layers. The rock strata and soil layers with a resistivity of less than 15 Ωm were interpreted as zones of contamination. Also, samples of groundwater were collected from four boreholes and six hand-dug wells for water quality and physicochemical analysis. The analysis shows that iron (Fe), total dissolved solids, Sulfate (SO 4) and turbidity exceeded the recommended thresholds for drinking water. Consequently, the water quality index result showed that 2% of the samples produced good water, 1% produced water of poor quality, 20% of the samples produced very poor water, and 50% produced water unsuitable for human consumption. Subsequently, a radiation spectrometer was deployed to measure the radioelement concentration to determine the radio hazard and environmental pollution status of the area. Measurements of radiation due to man-made sources were undertaken in the ten profiles. The mean concentration and mean specific activity were determined for all the survey lines. While the mean concentration of 40 K and radiation dose rate were recorded below UNSCEAR's (2000) proposed limits. 238 U and 232 Th exceeded the recommended threshold for profiles seven to ten. The annual effective dose equivalent (AEDE) in the area was also calculated to be 40.98 Sv/year. The research provides a multi-geophysical approach to evaluating and understanding hydro-geophysical and geo-environmental conditions related to landfill contamination.
Water quality monitoring of Oguta Lake and associated rivers (Utu, Awbana, Orashi and Njaba River... more Water quality monitoring of Oguta Lake and associated rivers (Utu, Awbana, Orashi and Njaba Rivers) over a one year period was conducted to ascertain the variability of the surface water bodies with respect to biochemical constituents. A total of 30 water samples collected from Oguta Lake and 24 water samples from the associated rivers were analyzed using the AAS (atomic absorption spectrophotometer), digital meters and membrane filters. Results of the analyses showed that the pH of Oguta Lake water varied from 5.1 to 6.5 with a mean value of 5.92, while the mean pH value of Rivers Utu, Awbana, Orashi and Njaba was 6.35, 6.30, 6.20 and 6.40, respectively. The DO (dissolved oxygen) values of Oguta Lake water ranged from 5.6 to 8.0 mg/L with a mean value of 7.01 mg/L, while the BOD (biochemical oxygen demand) ranged from 1.6 to 3.0 mg/L with a mean value of 2.95 mg/L. The mean values of DO for Rivers Utu, Awbana, Orashi and Njaba were 6.87, 7.20, 7.40 and 8.10 mg/L, respectively, and the mean BOD values were 0.75, 0.70, 0.66 and 1.33 mg/L, respectively. Mean SAR (sodium adsorption ratio) of the Oguta Lake was 0.58 while those of Rivers Utu, Awbana, Orashi and Njaba were 0.77, 0.81, 0.72 and 0.64, respectively. The relative abundance of major cations in the Oguta Lake water and its associated rivers followed the trend of Na + > Ca 2+ > K + > Mg 2+ while the major anions followed the trend HCO3 - >SO4 2- >Cl - > NO3 - . Piper Trilinear Plots showed that the lake and associated rivers plotted on the potable water zone. The Piper Trilinear and Stiff Diagrams indicated strong positive chemical relationship between the lake and associated rivers. Except for low pH and high counts of microbial constituents in both the lake waters and the associated rivers, measured chemical parameters were in conformity with the WHO (World Health Organization, 2006) standard for safe drinking water. The Oguta Lake and associated rivers waters can be described as soft, fresh and suitable for domestic purposes (if treated for pH and bacteria). The lake and associated rivers are, however, excellent for irrigation purposes based on their SAR values.
The Ajali Formation outcrops at Okigwe, Ihube, Onyekaba mine, Uturu and Isiukwuato in the Anambra... more The Ajali Formation outcrops at Okigwe, Ihube, Onyekaba mine, Uturu and Isiukwuato in the Anambra Basin southeastern Nigeria were evaluated for an integrated field, sedimentologic and petrograpic methods. The study was aimed at presenting a better understanding of the depositional processes and provenance. Five lithofacies were altogether described namely: planar Cross bedded sandstone facies A, Massive sandstone facies B, Ferruginized sandstone facies C, herringbone cross bedded sandstone facies D, and Bioturbated sandstone facies E. The facies were deposited in a fluvially influenced shallow marine environment. The overall grain size interpretation shows that sediments from the study area are fine to coarse grained with values ranging from 0.2 to 2.0Φ, poorly sorted to very well sorted with range value of 0.28 to 1.2Φ, nearly symmetrical to strongly fine skewed with values of -0.04 to 0.59Φ and platykurtic to very leptokurtic with values of 0.79 to 2.46Φ. An inspection of the cumu...
Anambra Basin is one of the most economically strategic watersheds in southeastern Nigeria and oc... more Anambra Basin is one of the most economically strategic watersheds in southeastern Nigeria and occupies an area of about 95,000km. It not only has abundant water resources but also holds potentials for oil and gas deposits. Hydrostratigraphically, the basin is underlain by the Nkporo, Mamu, Ajali and Nsukka Formations as well as the Imo and Bende-Ameki Formations. Using existing literature, this review presents the hydrogeochemical characteristics of the underlying groundwater system. The aquifer units are characterized by two distinct ionic regimes: Ca-HCO3 and Na-SO4. The later is associated with the deeper groundwater flow system within the Mamu Formation while the former occurs in the upper shallow flow system within the Ajali Sandstone. The regimes have been explained in terms of the Chebatorev groundwater geochemical evolution model moderated by “order of encounter” and cation exchange processes.
The hydrogeochemical evolution and irrigation suitability assessment of groundwater in selected p... more The hydrogeochemical evolution and irrigation suitability assessment of groundwater in selected parts of Asaba, Nigeria, has been conducted. The purpose of this study was to ascertain the hydrogeochemical relations and interactions of groundwater with rocks, and also assess the usefulness of the groundwater for irrigation purpose. Twenty (20) groundwater samples were analyzed for physical and chemical compositions. All tested water parameters were within the WHO (2017) recommended standard for drinking water except for Fe 2+ , which showed worrisome amount. Furthermore, hydrogeochemical plot with Piper trilinear diagram showed that groundwater samples in the study area is sodium bicarbonate and mixed water types and Schoeller semi-logarithmic plot showed an ionic trend of HCO 3 − + CO 3 2− > Na + + K + > Mg 2+ > Ca 2+ > SO 4 2− > Cl − . Langelier and Ludwig diagrams reveal that the hydrogeochemical evolution trend is towards the Cl − -SO 4 2− -Na + + K + compositions. The indices of Chloro-Alkaline (CA) and Index Base Exchange (IBE) shows that the CA1 and CA2 are negative, implying that there is an exchange between (Na + + K + ) in the groundwater and (Ca 2+ + Mg 2+ ) of rocks. For the irrigation suitability, the SAR, %Na + , RSC, and MR ranged between 0.5 to1.49, 44.6 to 81.5, 0.48 to 2.02, and 9.61% to 98.8%, respectively. These imply that most of the tested groundwater could be used for irrigation purposes, while some are considered unfit for such. Therefore, regular routine assessment of the groundwater is recommended to ascertain its suitability for agriculture (irrigation) and domestic uses.
Abstract Rock physics enhanced seismic strati-structural interpretation of the "Wuzozo Field... more Abstract Rock physics enhanced seismic strati-structural interpretation of the "Wuzozo Field" revealed two genetic units with the reservoir sands interpreted as channel fill deposits belonging to the Low Stand Systems (LST) and Trangressive Systems Tracts (TST) respectively. Estimated effective bulk moduli of the field revealed values between 23.55-36.74GPa for sand bodies while the results of the rock physics modeling revealed that the elastic moduli increases as porosity values decrease. Evaluation of the reservoir properties indicated that the pay zones are high-quality sands owing to their high effective porosities and net-to-gross ratio. In conclusion, the integration of rock physics with seismic stratigraphy has proved to be an invaluable tool for identifying prospective pay zones, especially at deeper subsurface intervals.
International journal of environmental science and technology, Apr 21, 2024
The study was conducted in an old landfill in the Calabar South local government area of Cross Ri... more The study was conducted in an old landfill in the Calabar South local government area of Cross River State. The essence of the research work is to investigate groundwater quality within the area and evaluate the level of environmental pollution due to radioelement exposure to landfill waste. Ten profile (traverse) lines were created for the survey, and twenty vertical electrical soundings were probed with a maximum half-current electrode (AB/2) of 200 m. The result revealed four to five geoelectric layers. The rock strata and soil layers with a resistivity of less than 15 Ωm were interpreted as zones of contamination. Also, samples of groundwater were collected from four boreholes and six hand-dug wells for water quality and physicochemical analysis. The analysis shows that iron (Fe), total dissolved solids, Sulfate (SO 4) and turbidity exceeded the recommended thresholds for drinking water. Consequently, the water quality index result showed that 2% of the samples produced good water, 1% produced water of poor quality, 20% of the samples produced very poor water, and 50% produced water unsuitable for human consumption. Subsequently, a radiation spectrometer was deployed to measure the radioelement concentration to determine the radio hazard and environmental pollution status of the area. Measurements of radiation due to man-made sources were undertaken in the ten profiles. The mean concentration and mean specific activity were determined for all the survey lines. While the mean concentration of 40 K and radiation dose rate were recorded below UNSCEAR's (2000) proposed limits. 238 U and 232 Th exceeded the recommended threshold for profiles seven to ten. The annual effective dose equivalent (AEDE) in the area was also calculated to be 40.98 Sv/year. The research provides a multi-geophysical approach to evaluating and understanding hydro-geophysical and geo-environmental conditions related to landfill contamination.
Water quality monitoring of Oguta Lake and associated rivers (Utu, Awbana, Orashi and Njaba River... more Water quality monitoring of Oguta Lake and associated rivers (Utu, Awbana, Orashi and Njaba Rivers) over a one year period was conducted to ascertain the variability of the surface water bodies with respect to biochemical constituents. A total of 30 water samples collected from Oguta Lake and 24 water samples from the associated rivers were analyzed using the AAS (atomic absorption spectrophotometer), digital meters and membrane filters. Results of the analyses showed that the pH of Oguta Lake water varied from 5.1 to 6.5 with a mean value of 5.92, while the mean pH value of Rivers Utu, Awbana, Orashi and Njaba was 6.35, 6.30, 6.20 and 6.40, respectively. The DO (dissolved oxygen) values of Oguta Lake water ranged from 5.6 to 8.0 mg/L with a mean value of 7.01 mg/L, while the BOD (biochemical oxygen demand) ranged from 1.6 to 3.0 mg/L with a mean value of 2.95 mg/L. The mean values of DO for Rivers Utu, Awbana, Orashi and Njaba were 6.87, 7.20, 7.40 and 8.10 mg/L, respectively, and the mean BOD values were 0.75, 0.70, 0.66 and 1.33 mg/L, respectively. Mean SAR (sodium adsorption ratio) of the Oguta Lake was 0.58 while those of Rivers Utu, Awbana, Orashi and Njaba were 0.77, 0.81, 0.72 and 0.64, respectively. The relative abundance of major cations in the Oguta Lake water and its associated rivers followed the trend of Na + > Ca 2+ > K + > Mg 2+ while the major anions followed the trend HCO3 - >SO4 2- >Cl - > NO3 - . Piper Trilinear Plots showed that the lake and associated rivers plotted on the potable water zone. The Piper Trilinear and Stiff Diagrams indicated strong positive chemical relationship between the lake and associated rivers. Except for low pH and high counts of microbial constituents in both the lake waters and the associated rivers, measured chemical parameters were in conformity with the WHO (World Health Organization, 2006) standard for safe drinking water. The Oguta Lake and associated rivers waters can be described as soft, fresh and suitable for domestic purposes (if treated for pH and bacteria). The lake and associated rivers are, however, excellent for irrigation purposes based on their SAR values.
The Ajali Formation outcrops at Okigwe, Ihube, Onyekaba mine, Uturu and Isiukwuato in the Anambra... more The Ajali Formation outcrops at Okigwe, Ihube, Onyekaba mine, Uturu and Isiukwuato in the Anambra Basin southeastern Nigeria were evaluated for an integrated field, sedimentologic and petrograpic methods. The study was aimed at presenting a better understanding of the depositional processes and provenance. Five lithofacies were altogether described namely: planar Cross bedded sandstone facies A, Massive sandstone facies B, Ferruginized sandstone facies C, herringbone cross bedded sandstone facies D, and Bioturbated sandstone facies E. The facies were deposited in a fluvially influenced shallow marine environment. The overall grain size interpretation shows that sediments from the study area are fine to coarse grained with values ranging from 0.2 to 2.0Φ, poorly sorted to very well sorted with range value of 0.28 to 1.2Φ, nearly symmetrical to strongly fine skewed with values of -0.04 to 0.59Φ and platykurtic to very leptokurtic with values of 0.79 to 2.46Φ. An inspection of the cumu...
Anambra Basin is one of the most economically strategic watersheds in southeastern Nigeria and oc... more Anambra Basin is one of the most economically strategic watersheds in southeastern Nigeria and occupies an area of about 95,000km. It not only has abundant water resources but also holds potentials for oil and gas deposits. Hydrostratigraphically, the basin is underlain by the Nkporo, Mamu, Ajali and Nsukka Formations as well as the Imo and Bende-Ameki Formations. Using existing literature, this review presents the hydrogeochemical characteristics of the underlying groundwater system. The aquifer units are characterized by two distinct ionic regimes: Ca-HCO3 and Na-SO4. The later is associated with the deeper groundwater flow system within the Mamu Formation while the former occurs in the upper shallow flow system within the Ajali Sandstone. The regimes have been explained in terms of the Chebatorev groundwater geochemical evolution model moderated by “order of encounter” and cation exchange processes.
The hydrogeochemical evolution and irrigation suitability assessment of groundwater in selected p... more The hydrogeochemical evolution and irrigation suitability assessment of groundwater in selected parts of Asaba, Nigeria, has been conducted. The purpose of this study was to ascertain the hydrogeochemical relations and interactions of groundwater with rocks, and also assess the usefulness of the groundwater for irrigation purpose. Twenty (20) groundwater samples were analyzed for physical and chemical compositions. All tested water parameters were within the WHO (2017) recommended standard for drinking water except for Fe 2+ , which showed worrisome amount. Furthermore, hydrogeochemical plot with Piper trilinear diagram showed that groundwater samples in the study area is sodium bicarbonate and mixed water types and Schoeller semi-logarithmic plot showed an ionic trend of HCO 3 − + CO 3 2− > Na + + K + > Mg 2+ > Ca 2+ > SO 4 2− > Cl − . Langelier and Ludwig diagrams reveal that the hydrogeochemical evolution trend is towards the Cl − -SO 4 2− -Na + + K + compositions. The indices of Chloro-Alkaline (CA) and Index Base Exchange (IBE) shows that the CA1 and CA2 are negative, implying that there is an exchange between (Na + + K + ) in the groundwater and (Ca 2+ + Mg 2+ ) of rocks. For the irrigation suitability, the SAR, %Na + , RSC, and MR ranged between 0.5 to1.49, 44.6 to 81.5, 0.48 to 2.02, and 9.61% to 98.8%, respectively. These imply that most of the tested groundwater could be used for irrigation purposes, while some are considered unfit for such. Therefore, regular routine assessment of the groundwater is recommended to ascertain its suitability for agriculture (irrigation) and domestic uses.
Abstract Rock physics enhanced seismic strati-structural interpretation of the "Wuzozo Field... more Abstract Rock physics enhanced seismic strati-structural interpretation of the "Wuzozo Field" revealed two genetic units with the reservoir sands interpreted as channel fill deposits belonging to the Low Stand Systems (LST) and Trangressive Systems Tracts (TST) respectively. Estimated effective bulk moduli of the field revealed values between 23.55-36.74GPa for sand bodies while the results of the rock physics modeling revealed that the elastic moduli increases as porosity values decrease. Evaluation of the reservoir properties indicated that the pay zones are high-quality sands owing to their high effective porosities and net-to-gross ratio. In conclusion, the integration of rock physics with seismic stratigraphy has proved to be an invaluable tool for identifying prospective pay zones, especially at deeper subsurface intervals.
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