Abstract: Surface water is an important water resource for drinking and irrigation purposes in the central part of Ekiti-State. The water bodies are used with little attention to their quality status in addition to increased threat of anthropogenic contamination in view of rapid growth in population. The objectives of this study were to determine the physico-chemical characteristics of surface water, its hydrochemical controls and suitability for drinking and irrigation. Forty surface water samples were investigated. Field measurements of physical parameters were preceded by chemical analyses of the samples for major ions concentrations and bacteriological content. The surface water has pH ranging from 8.3 – 9.6 implying that the water was barely alkaline. Electrical conductivity [<205 µS/cm] and total dissolved solids [<154 mg/l] were low suggesting low-mineralised freshwater. The relative abundance of major ions [mg/L] was Na⁺>Ca²⁺>Mg²⁺>K⁺ for cations and Cl^- >SO₄^2-> HCO₃^->NO₃^- for anions. Major ion concentrations were low and within the WHO guidelines for drinking water indicating chemical suitability of surface water. The water samples tested positive to total bacterial count and E – coli with median values of 31.50 and 8.00 (cfu/100ml) respectively. Main water types and proportions were [70 %] mixed Ca²⁺-Mg²⁺-Cl^-, [20%] Na⁺-Cl^- and [10%] Ca²⁺-Cl^-. Predominant processes influencing water chemistry were incongruent dissolution/weathering of silicate minerals and cation-exchange of Na⁺ in rocks for Ca²⁺ in water. The low major ion concentrations indicated low water-rock interactions and short residence time. Irrigation quality indices [Sodium absorption ratio, salinity hazard, Kelly ratio and permeability index] revealed that the analysed water was suitable for irrigation.

Abstract: Congo red, a conjugated diazo dye which is a derivative of benzidine and napthionic acid, has experienced commercial success because of its ability to dye cotton easily. The unregulated disposal of textile dyes, such as Congo red, has created a challenge for environmental chemists to determine effective, inexpensive treatment processes for remediating contaminated water. Studies involving semiconductors such as titanium dioxide (TiO₂) and zinc oxide (ZnO) have investigated their affects on wastewaters after being irradiated. However, few reports have described the influence temperature has on such systems. The objective of this study was to briefly characterize, via UV-Visible spectroscopic techniques, the temperature-dependency of the photocatalytic degradation of Congo red using zinc oxide and an inexpensive radiation source. The results indicate that the rate of degradation is catalytically dependent, photo-induced, and potentially temperature dependent with the greatest rate of degradation observed in trials conducted at low (~5°C) temperature. The results may also suggest the prevalence of aggregate dye formation at elevated (~40°C) temperature, although photocatalytic degradation is likely to occur concurrently.

Abstract: The objective was to investigate groundwater quality in boreholes located in Uyo urbanized state capital, and four contiguous Local Government Areas (LGAs) of Ibiono Ibom, Ikot Ekpene, Itu and Nsit Ubium, under Coastal Plain Sands(CPS) formation, for spatial and temporal variability of groundwater quality and compatibility with Nigerian Standards for Drinking Water Quality (NSDWQ)indicating prospects of pollution diffusion due to urbanization spread. Standard examination methods were employed as well as morphological and bacteriological counts. Data on waterquality properties were statistically analyzed using SPSS software version 17 for descriptive statistics, covariance (CV), ANOVA and for percentage compatibility computations. Data on Uyo samples showed the lowest values while Ibiono showed median values; heavy metals showed highest spatial variability at CV ≥ 35%. Significant difference (P < 0.1) was observed in temporal variability between 2013 and 1993 values (20 years interval). The suggested causes were: spread of pollution by construction ruts, stagnant polluted water, and vehicular traffic commuting urban-rural areas, open uncontrolled dumping of various solid/organic wastes, insanitary handling of water and wastewater and low standard of borehole drilling in rural-urban fringe adjusting to suburbanization. Compatibility with NSDWQ varied per parameter and location but were generally within acceptable standards; however, iron, lead and cadmium in the contiguous LGAs were higher in concentrations and should be periodically monitored. Bacterial counts, especially coliform count exceeded standard MPN and called for sanitation intensification.

Abstract: Three point sources of pollution of urban drainage stream, Uyo, namely: Municipal Solid Water Leachate effluent (MSWL), Municipal Waste Water (MWW) and Abattoir Waste Water (AWW),were identified and characterized using standard water examination methods to determine their constituent quality.Variance homogeneity, correlations of paired PS were tested with ANOVA and covariance using SPSS version 17. Paired samples correlations showed very high correlations (R = 92 – 99%). However, when properties were disaggregated into similar elemental constituents and tested, AWW and MSWL (in wet season) showed variance difference in solids and nutrients; all others showed variance homogeneity in heavy metals. Selective monitoring and control of common critical constituent pollutants is recommended.

Abstract: This paper makes an attempt to delineate groundwater potential zones in a catchment by using scientific information of lithology, topography, geophysical characterization and their interrelationship. On the basis of relative contribution of each of thematic layers towards groundwater potential, the weight of each thematic map has been selected. The individual theme weight was multiplied by its respective class weight and then all the raster thematic layers were aggregated in a linear combination equation. Groundwater potential zones map revealed that the plain areas are prospective zones in the catchment and can be helpful in better planning and management of ground resources.