The capacity of unripe plantain (Musa paradisiaca) peel biomass to remove heavy metals, Pb(II) and Mn(II) from aqueous solution of lead trioxonitrate (v), Pb (NO3)2 and potassium permanganate, (KMnO4) was investigated. Adsorption isotherms were determined by varying operating parameters such as effect of pH, initial concentration, adsorbent dose and contact time. Unripe plantain(Musa paradisiaca) peel was found to remove Pb and Mn ions in solution. Removal rate of Pb(II) and Mn(II) was found to increase steadily from pH 2 , however, Pb(II and Mn (II) removal decreases at pH 8. Langmuir and Freundlich models were applied to adsorption equilibrium data to find the best fitted amongst these models. Langmuir model type 1, with R 2 = 0.9823 best fitted for Pb (II) adsorption data. The separation parameter, RL values were less than 1.0 i.e., 0.000903, 0.000451, 0.000225 and 0.000150 with corresponding initial concentrations of (50, 100, 200 and 300) mg/L respectively. This indicates that adsorption of Pb (II) ion on unripe plantain(Musa paradisiaca) peel biomass was favourable to Langmuir isotherm, while Freundlich model with R 2 = 0.9585 best fitted Mn (II) ion with (n) value of 1.03, which was favourable adsorption. Thus, the results of these findings showed that unripe plantain (Musa paradisiaca) peel biomass could be effectively and efficiently utilized for the removal of Pb (II) and Mn (II) ions from aqueous solution.

AbstractThe aim of this study was to evaluate the polycyclic aromatic hydrocarbons load in soils of Ogale community, Rivers State, Nigeria and as well delineate the lateral and vertical extensions of the soils and groundwater. Geo-electric characterization of the soils and groundwater, using Electrical Resistivity methods (vertical electrical sounding, VES by Abem Terrameter and Gas chromatograph - Flame Ionization Detector (GC-FID) for finger-print was employed. The interpreted VES results revealed four geo-electric subsurface layers. The first layer which has a resistivity value of 60Ωm and a thickness of 2.0M was interpreted as top soil. Underlying the first layer is the second layer which had a resistivity value of 122Ωm with a thickness of 3m, interpreted as lateritic sand. The third layer had a resistivity value of 750Ωm and a thickness of 9.0m, and is interpreted as coarse sand. The fourth layer which had a resistivity value of 1255Ωm and a thickness of 49m is interpreted as very coarse sand. Borehole one was used as control and it is 1.85km away from the Resistivity sampling points. The results revealed that the presence of C10-C40 hydrocarbon which indicates un-weathered to fresh hydrocarbon in parts of the study area and heavy metals were below detection limits. The vulnerability of the aquifer to hydrocarbon contamination was due to high permeability, unconsolidated coarse grained and poorly sorted sands, of the vadose zone as well as shallowness of the aquifer. It is recommended that boreholes in the study area should be of deeper depths, and well constructed to avoid contaminated water from the polluted zone entering the borehole through the annulus.

This study was carried out to evaluate the pollution status in water, sediments and whole body tissue of clam (galatea paradoxa, born 1778) of the Diebu Creek, Bayelsa State, Niger Delta Region, Nigeria. The concentrations of the five heavy metals (As, Co, Cu, Fe and Pb) were determined using analyst 400 Perkin Elmer Atomic Absorption Spectrophotometer (AAS). The mean concentration(mg/kg) of the metals in sediment were: (0.66±0.76) Co, (1.56±1.16)Cu, (1812.31±190.31)Fe and (0.94±0.87)Pb, while the mean concentration(mg/kg) of the metals in clam followed decreasing order: Fe(284.22)> Pb(2.30)> Co(1.08)>Cu(0.75) respectively. In attempt to infer anthropogenic input from natural input, linear regression equation, comparison with sediment quality guideline (SQGs) and ecotoxicological sense of heavy metal contamination was employed. The concentration of the studied heavy metals of the Diebu Creek, Fe and Pb exceeded reference standards, however, the concentration does not pose a threat to the sediment dwelling fauna and anyone who consumes aquatic animals particularly clam (galatea paradoxa, born 1778) from the Diebu Creek. According the SQGs, the studied heavy metals of the Diebu Creek sediment were under the category of non-polluted.