GEOPHYSICAL INVESTIGATION OF THE IMPACT OF POULTRY WASTE EFFLUENT ON SOIL PROPERTIES AT IJAKO VILLAGE EPE SOUTHWEST NIGERIA

Abstract

ABSTRACT Poultry waste effluents, especially liquid discharges, often contain high levels of nitrates, phosphates, pathogens, heavy metals, and organic contaminants. When released into the surrounding environment, these effluents can percolate through the soil and seep into aquifers, causing both shallow and deep groundwater pollution. The present study is carried out with the aim of investigating the subsurface impact of poultry waste effluent on soil and groundwater quality in Ijako Village, Poka, Epe, Southwest Nigeriausing geophysical techniques. Electrical resistivity method was employed to map the vertical and lateral variations in subsurface resistivity. A total of ten(10) VES stations were probed utilizing Schlumberger electrode array mode and eight 2D profiles were acquired usingWenner array configurations, respectively. The survey was carried out using the campus tigre resistivity meter. The VES data were processed using both partial curve matching and WIN RESIST software in order to generate thicknesses and resistivities and the 2-D data were processed using the RES2DINV software to get the 2D resistivity imaging (inversion) and subsurface resistivity models from field data. The results of the VES data for the study area revealed that the KQ curve type was the predominant type, made up of the four layers (ρ₁ < ρ₂ < ρ₃ > ρ₄). The second dominating curve type is the HK type (ρ₁ > ρ₂ < ρ₃ > ρ₄), followed by the HQ type (ρ₁ > ρ₂ < ρ₃ < ρ₄), and lastly QH (ρ₁ < ρ₂ > ρ₃ < ρ₄). The geologic layers identified include topsoil, clay, clayey sand, sandy clay, sand, lateritic soil. The RMS errors obtained from the model inversion ranged between 1.8% and 4.7%. The topsoilconsistedmainlyofclay,clayeysand,sandyclay,andlateriticsoil,withresistivityvaluesrangingfrom4.5to662.3Ωmandthicknessrangingfrom0.2to1.9m.Thesecondlayercomprisedsandyclay,lateriticsoil withresistivityvaluesrangingfrom6.6to414.7Ωmandthicknessrangingfrom0.3to7.4m.Thethirdlayerinterpreted lateritic clay inmostlocationswithresistivityvaluesrangingfrom4.1to18900.0Ωmandthicknessrangingfrom0.7to16.6m.Thefourthlayerhasanindicativeoffresh clay withresistivityvaluesrangingfrom7.4to11244.0Ωm. The 2D ERI profiles demonstrated a spread of horizontal distance of about 45m and vertical penetration of approximately 6 meters. This research provides an evidence of the environment impact of poultry waste effluent on both soil and subsurface structures in IJAKO VILLAGE.