Seasonal Variations of pH and Heavy Metals Content in Soil of Selected Housing Estates in Ogun State, Nigeria

There is a necessity to assess soil properties with the view to determining soil qualities relative to pollution and sustainability of ecosystem functions and plant productivity regardless of the scale. Soil samples (six points per site at 0-15 cm depth) from six selected housing estates across Ogun State were assessed for soil pH and heavy metals pollution in two dry and rainy seasons. The soil samples were digested using standard methods and analysed for seven selected metals: Mn, Fe, Cu, Zn, Ni, Pb and Cd using AAS. The data obtained were subjected to descriptive and inferential statistics. Concentrations (mg/ kg) of the analysed metals were observed to vary from the lowest in the 2nd rainy season to the highest in 1st dry season respectively as Pb: 3.57 ± 0.02 to 39.87±0.47, Cd: 0.32±0.03 to 2.65±1.02, Mg: 11.94 ± 0.76 to 204.50 ± 15.02, Fe: 22.79 ± 0.45 to 303.50±16.52, Cu: 0.95±0.21 to 6.02±1.12, Zn: 0.12 ± 0.04 to 12.75±0.68, and Ni: 2.38 ± 0.33 to 33.89±0.37. There were indications that the soil samples were comparatively less polluted in the rainy seasons.Key words: soil qualities, ecosystem function, dry and rainy seasons, Nigeri

The Effects of Storage on Sachet Water Quality in Ogun State, Nigeria

The purpose of this study is to investigate the effect of storage on the physicochemical status and bacteriological quality of sachet water produced and sold in  Abeokuta metropolis, Nigeria. Ten brands of sachet water were collected within 24 hours of production and stored at ambient temperature. Sub-samples were drawn from the stock samples immediately for physico-chemical and microbiological analyses and after two months. Physical parameters were determined by instrumental methods. Cationic and anionic constituents were determined by standard titrimetric and spectrophotometric methods, trace and heavy water were determined by Atomic Adsorption Spectrophotometer. The study revealed that all the brands of water analyzed were physically and chemically wholesome and met the WHO standards. Five brands (50%) of the water had total viable and coliform count above the recommended count of 100cfu/m and zero cfu/ml, respectively. pH values increased in all brands to acceptable WHO limits within 2 months of storage except for sample 3 and 4 which decreases below the acceptable limit.  Majorly dissolved oxygen and nitrate values decreased through the investigation period. Total and faecal coliform appeared in 50% of sachet water samples  analyzed immediately after production and were no longer detected after storing for two months except for sample 4. Results of the experiment indicate that 60% of the brands analyzed met the WHO guideline limit for drinking especially for the physico-chemical parameters while the majority failed in the microbiological essay when stored at ambient temperature for the two-month investigation period.KEYWORDS: Coliforms, Conductivity, Microbiological Assay, Physical and Chemical Parameters,Turbidity, Sachet Wate