Morpho-physiological characteristics of Vigna unguiculata [L.] Walp grown in a controlled environment using effluents from a beverage bottling company.

The use of industrial effluents for agricultural practices due to waste management properties, water scarcity, or cultural belief affects both the physiology and morphology of cultivated crops. This study reports the investigation of the agro-potentiality of the effluents from a beverage bottling company on cowpea (Vigna unguiculata) under a controlled environment. This greenhouse experiment was carried out within Obafemi Awolowo University. The effluents were applied at 0, 10, 20, 30, 40, and 50% concentrations using untreated (A) and treated (B) effluents separately in two groups. Physicochemical properties of the effluents were determined using standard methods. Exchangeable cations present in the effluents were investigated via the ammonium acetate exchange way. Morphological and yield parameters were measured in ten replicates. Transverse sections of the leaf, petiole, and stem were also investigated under a light microscopy. General linear model was used for statistical analysis with means compared using Tukey's HSD test at p < 0.05. The effluents had pH, electrical conductivity, and total dissolved solids in the range of 7.4-7.5, 599.0-693.0 µS/cm, and 395.0-455.0 mg/l, respectively. The exchangeable calcium and potassium concentrations in the effluents range 1067.00-1937.50 and 190.0-343.50 mg/l. Application of effluent A had no significant effect on number of pods per group, seeds per pod, leaf length, leaf width, and leaf area of cowpea (p > 0.05). There was a significant effect of effluent A on the number of leaves and shoot height (p < 0.05). The application of effluent B had a significant effect on the mean number of leaves and seeds per pod at higher (40-50%) concentrations (p < 0.05). Amendment with effluent B showed no significant effect on the mean shoot height, leaf length, width and area, pods per group, pod length, and girth size (p > 0.05). The frequency of guard cells was observed to decrease with increasing effluents (A and B) concentration on the abaxial epidermis. Likewise, a "black deposit" was observed in the vessels in the stem taken from group amended with effluent A at high concentrations (30-50%). No anatomical differences were observed in the petiole and leaf transverse sections of the control and amended subgroups. The untreated and treated effluents showed agro-potentiality. However, crops grown need to be monitored for the health impacts on man and animal, as risk of crop cellular disruption exist.

Geochemical characterization of soil samples from gold mining areas using PIXE spectroscopy.

Particle-induced x-ray emission (PIXE) spectroscopy has been used to characterize soil samples from two relatively old gold mine sites (Iperindo and Itagunmodi) in the Ilesha schist belt of Southwestern Nigeria. This is with a view to identifying the indicator or pathfinder elements of gold for fingerprinting and toxicity potential assessment purposes. Average elemental concentrations of 19 major, minor, and trace elements were determined, and the geochemical data of Mn, Ni, Cu, Zn, Ag, As, Pb, and Au together with multivariate factor and cluster statistical analyses allowed to identify As and Ag as the pathfinder elements of gold. The high concentration of the determined pathfinder elements (As and Ag) as well as other toxic metals (Pb and Cu) implies a relatively high metal contamination risk to the miners and the ecosystem. The major hazard is represented by the abandoned mining wastes, pits, and ponds, already serving as fish ponds.

Radiological indices of technologically enhanced naturally occurring radionuclides: a PIXE approach.

This paper reports an assessment of the level of the radionuclides (40)K, (232)Th and (238)U in environmental soil samples (process waste), and hence their calculated dose rates. For this purpose, the radioactivity from three natural radionuclides was determined in tin process-waste samples in Jos, Nigeria. This work is based on the particle induced x-ray emission (PIXE) approach, devoid of the secular equilibrium, and most of the resolution, interference, self-absorption, geometrical and density correction problems inherent in gamma spectrometry. Many potential environmental hazards have been observed and the data would be of use to the government in its remediation plan for the study area. The high hazard indices require taking adequate measures to check exposures, and an underground lining in the waste ponds to prevent direct contact with the waste pile is recommended. The use of the wastes as building materials should be stopped and use of soils around this area in any development projects should be discouraged until detailed studies on indoor radiation doses and the effects on the inhabitants of prolonged exposures have been carried out.