Hydrogeochemical-geophysical investigations of groundwater quality and susceptibility potential in Ikot Ekpene - Obot Akara Local Government Areas, southern Nigeria

Aniekan M. Ekanem; Ndifreke I. Udosen

Abstract: Groundwater contamination is of global concern. The study area (Ikot Ekpene - Obot Akara Local Government Areas) continues to experience a swift increase in human population and associated economic activities, leading to the generation of more solid wastes. This could result in groundwater contamination, which can put the local pollution in severe danger. The fundamental goal of this work is therefore to weigh up the groundwater standard through hydrogeochemical investigation of groundwater samples and the susceptibility potential of the economically exploited aquifer units in the area. The results of the electrical geo-sounding data acquired at 28 locations in the area reveal three to four lithological successions comprising fine/coarse sands and gravels amid patches of thin clay interbeddings at several places. The primary aquifer in the area is the third layer, which is between 10.5 and 101.5 m deep with resistivity values between 359.4 and 2,472.8 Ωm. The hydrogeochemical evaluation of groundwater samples in the area shows that the measured physicochemical parameters are well within the World Health Organization’s acceptable limits except for lead and nickel ions. These metals are shown to be the most significant parameters affecting the groundwater quality in the area. The groundwater quality and susceptibility potential maps generated seem to correlate well and clearly demarcate the poor groundwater quality/high susceptibility potential zones. These maps are useful tools that could aid policymakers in successful groundwater management in the area to meet the needs of the populace.

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Groundwater potential and quality assessments of a coastal environment: a case study of the location of Federal University of Technology Ikot Abasi (FUTIA), Akwa Ibom State, Nigeria

George, N.J and Thomas, J.E

Abstract: The economic, residential, agricultural, educational, and social relevance of groundwater to coastal residents provoked the selection of FUTIA and its surroundings, located along the Okpobo River and Atlantic Ocean shorelines, for integrated geo-electrical and hydrochemical investigations. This was done to better understand the potentiality, vulnerability, and agronomic implications of using groundwater for home, industrial, and irrigation purposes, which would lead to better planning, management, and conservation of the resource. By applying vertical electrical method involving 1-D and 2-D techniques, potentially prolific surficial (< 30 m depth) and moderately deep (>30 m depth  200m) aquifers were delineated. The study area is fraught with surficial unconfined aquifers drilled to follow the depths of the preexisting productive but vulnerable aquifers near them. The untapped semi-confined to confined aquifers for depths > 30 m and less than 200 m were viewed to have less susceptibility to contaminations due to the presence of overlying argillaceous units concealing them...

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DEVELOPMENT AND EVALUATION OF A CONSTRUCTED PILOT- SCALE HORIZONTAL SUBSURFACE FLOW WETLAND TREATING PIGGERY WASTE WATER

I.J. Udom , C.C. Mbajiorgu , E.O. Oboho

Abstract : Intensive piggeries are predominating livestock production and there is rising concern of nutrient pollution from the use of floodplains and water bodies as convenient sinks for the disposal of untreated wastewater. Conventional systems are not suitable solutions in preventing water pollution in developing countries due to their prohibitive cost and highly mechanized system with high energy and minimum inflow requirements which cannot be afforded by farmers. Natural systems, such as constructed wetlands are less costly, and have low energy requirements. However, lack of information on their performance in the tropics is among the factors that hinder their adoption as alternative wastewater treatment system. Successful removal of nutrients in piggery wastewater by constructed wetlands has been reported in different climatic regions outside Nigeria and their optimal design, performance, effects of plants and climate change on performance and the prediction of these effects need verification. The objective of this study was design, construct and test and model the performance of a horizontal subsurface flow wetland for treatment of piggery wastewater.

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