Assessment of Surface and Groundwater Quality of the Akure Metropolis, Southwestern Nigeria.

Hydrochemical analysis was carried out on surface and groundwater samples collected from Akure metropolis with a view to determining their quality. Hydrochemical data on groundwater samples from fifty six (56) boreholes were sourced from the Ondo State Water Corporation. Twenty five (25) surface water samples from streams and rivers in the study area were collected and analyzed using standard analytical techniques. The analyzed physical parameters include colour, odour, turbidity, conductivity and chemical properties such as pH, dissolved solid, hardness, cations, anions and heavy metals. All the groundwater samples were colourless, odourless and tasteless. Some surface water samples were coloured and turbid in appearance while some had objectionable odour. Although the NO3- concentration levels in both surface and groundwater samples were generally below the WHO threshold value of 10 mgl-1, relatively high concentration range (2.5-6.0 mgl-1) was recorded within the city centre indicating some level of pollution from cumulative anthropogenetic activities. Only few surface water samples contain Pb while Mn was identified in some surface and groundwater samples. The elevated Pb concentration levels (0.41-3.41 mgl-1) and relatively high Mn concentration levels (up to 2.18 mgl-1) (both much higher than the WHO and NIS thresholds) in some surface water samples was an indication of heavy metal pollution. Conductivity values of the groundwater samples generally ranged from 42.0 – 1400.0 µScm-1.  Only surface water sample 17 was moderately saline while other surface water samples were of freshwater type. Based on TDS values, all the groundwater and surface water samples were of freshwater type (TDS < 1000 mgl-1). Keywords: Physico-chemical Analysis, Surface/Groundwater, Quality, Akure Metropolis

Velocity-Porosity relationship in clastic formations – a case study from some parts of Niger Delta, Nigeria

Velocity-Porosity relationship in some parts of Niger Delta was studiesd with a view to establish the velocity-porosity relationship and the generalized equation(s) that best describe this relationship in clastic formations. Five wireline logs were acquired for the study. Neutron porosity log data was converted to synthetic velocity (VTA) using time-average equation of Wyllie (1956), and the sonic porosity log was converted to sonic velocity (Vsonic). The results were presented as velocity-porosity crossplots with the trend line equations and the coefficient of correlation. The results give a distinct inverse velocity-porosity relationship; i.e. velocity decreasing with increasing porosity. The velocity-porosity relationships established from both sonic log (Vsonic) and time-average formulation are best described by polynomial fitting of 2nd order. Two generalized equations of high coefficient of correlation, which can be used to calculate compressional velocity (Vp) from porosity values in clastic formations, were established from these relationship. Keywords: porosity, velocity, compressional, polynomial and clastic Global Journal of Pure and Applied Sciences Vol. 12(1) 2006: 125-12