Management of the ever-increasing generated solid waste had been a difficulty for state governments in Nigeria. The high costs connected to this waste management which had encumbered the state budget, ignorance or lack of understanding of resourceful waste management and insensitivity to environmental concerns may have led to partial neglect of this sector. This research paper is aimed at evaluating the rehabilitation potential and the risk level of Igbatoro dumpsite, an Ondo state-managed waste dumpsite which predominantly receives the waste of Akure and its environs. In determining rehabilitation/reconstruction potentials and assessing the risk of the dumpsite, an Integrated Risk Based Approach (IRBA) was considered. The Risk Index (RI) was calculated from the addition of the sensitivity index output with the attribute weightage of the twenty-seven (27) parameters studied. A total risk index of 571.58 was obtained for Igbatoro dumpsite indicating moderate hazard evaluation. Questionnaires distributed to dwellers around the dumpsite also showed that 83.6% of those interviewed agreed that the present management of the dumpsite is poor while 81.8% supported rehabilitation of the dumpsite. Hence, reconstruction of the Igbatoro dumpsite to an endurable and controlled landfill is hereby recommended.
Lagos is the world’s sixth largest city, the most populous city in Africa and the most populous city inNigeria. A total of eighteen groundwater exploitation borehole logs together with hydrogeological and geotechnical data were used for the study. The eighteen available borehole logs were categorized into seven areas spanning the shoreline to inland boundary ofLagosState. The study area has a high net recharge of1838mm/yr and the aquifer media is sand. The intrinsic vulnerability map show areas of highest potential for groundwater pollution based on hydro-geological condition and human impacts. Seven major hydro-geological factors incorporated into DRASTIC model and the geographic information system (GIS) were used to create a groundwater vulnerability map by overlaying the available hydro-geological data. The output map shows that the southeast of the aquifer is under very high vulnerability while central parts of aquifer have high vulnerability. Other parts (north, northwest and south) of the study area have moderate vulnerability to pollution. For testing of the vulnerability assessment, groundwater quality data were collated from literature for the different vulnerability zones of the study area. The chemical analysis results show that both the southeast and northwest west parts of study area aquifer (very high and moderate vulnerability zones) have higher nitrate concentration relative to the rest of aquifer, that are located in high vulnerability zone. The validation of the DRASTIC models was accomplished through pair wise comparison of DRASTIC vulnerability maps (using Pearson’s r correlation coefficient) with a total of 14 layers representing original DRASTIC input data, Land cover (LC) features, and groundwater TDS, Cl-and NO3 data. Results from the correlation analysis indicate a significant association between high groundwater TDS, NO3 concentrations and distances from certain LC types.
This research describes the goals, design and implementation of a quasi natural gradient, laboratory scale, sand tank (aquifer) model experiment. The model was used to study the transport of an inorganic tracer (Chloride) in groundwater, within a tropical aquifer (porous medium) material. Three-dimensional sand tank (1.8 m × 0.3 m × 0.8 m) experiments were conducted to investigate contaminant transport and natural attenuation within the sand tank. In all, 360 samples were collected during 24 sampling sessions, for the three days of the tracer experiments in the Sand Tank. The Owena sand is a poorly graded sand with 88.1 % sand and 11.9 % gravel. Geotechnical properties including; coefficient of uniformity C u = 2.53, coefficient of gradation C z = 0.181, hydraulic conductivity K = 5.76 x 10 -4 m/s, bulk density ρ = 1.9 Mg/m 3 , effective porosity n e = 0.215 and median grain diameter D 50 = 0.55 mm, were determined. Other relevant hydraulic and solute transport parameters, such as dispersion coefficients and dispersivities were also established for the tropical soil.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.