Assessment of Shallow Aquifers Contamination by Failure of on-Site Sewage Disposal System in Ughelli, Western Niger Delta, Nigeria

Hydrochemical quality of shallow groundwater aquifers was investigated to assess the potential of contamination by on-site sewage disposal systems in Ughelli. The results are; pH(5.47 – 7.45 ), Ec (105-483.2µscm), TDS( 58.95-294.7mg/l), Na+(1.8-10.95mg/l ), K+(2.64-9.87mg/l ), Mg2+( 2.40-9.89mg/l), Ca2+(3.01-14.90mg/l) and Fe2+ ( 0.02-0.87mg/l). Others include NO3 (0.04-31.24mg/l), NH3+ (0.015-6.98 mg/l), Cl- (8.5 - 104mg/l), SO4-(2.24-45.75mg/l), PO4-(0.21-2.25mg/l). The quality of most groundwater samples from shallow aquifers falls within the tolerance limits stipulated by the WHO and NSDWQ. However, some groundwater samples revealed the presence of high microbial population including total coliform bacteria count (1.78 – 25MNP/100ml) and Escherichia coli (1.35-9.66 MNP/100ml) above the WHO and NSDWQ standards.  Interaction between on-site sewage disposal systems and shallow groundwater aquifers was established  by the presence of microbial population, high concentration of NH3+ and slightly elevated concentration  of NO3, electrical conductivity and TDS in some the groundwater samples. The extent of contamination of groundwater is strongly influenced by depth of the aquifers, high recharge rate during the wet seasons and availability of permeable soil beneath on-site sewage disposal systems. Consequently the paper recommends that groundwater should be sourced from deeper aquifers and those sourced from shallow aquifer in the area should be disinfected before being used. Key words; Groundwater, aquifer, coliform, contamination, on-site disposal systems, WHO and NSDW

Heavy Metals Concentrations in Coal and Sediments from River Ekulu in Enugu, CoalCity of Nigeria

The levels of some heavy metals such as; Mn, Cr, Cd, As, Ni, and Pb were analysed in coal and sediment samples from River Ekulu in Enugu, Coal City using Atomic Absorption Spectrophotometer (AAS) model Spectra-AA-10 variant. Mean concentrations of Mn (0.256-0.389mg/kg) and Cr (0.214-0.267 mg/kg) are high relative to concentrations of Cd (0.036-0.043 mg/kg), As (0.016-0.018 mg/kg), Ni, (0.064-0.067 mg/kg) and Pb (0.013-0.017 mg/kg). Except for Mn, there is a steady decrease in the concentration of all metals from November to March corresponding to decreasing run-off. Metal concentrations are generally higher in the coal samples than in the sediments. Selectiveleaching of these metals is suspected from the trends of their concentration. Seasonal fluctuations are higher in the sediments than the coal samples. Correlation coefficients show that all the metals are positively correlated with each other implying that they are from the same source or origin. The presence of toxic metals in the area is established, calling for the assessment of their impact on the health of human and aquatic lives around the area. @JASE

Prevention of Carbon Tetrachloride-induced Hepatic Steatosis and Cellular Damage by Aqueous Extract of Dacryodes edulis Seeds in Wistar Rats

The protective effect of the aqueous extract of Dacryodes edulis seeds on the liver of rats exposed to carbon tetrachloride was investigated. Thirty female albino rats of Wistar strain were randomly allocated to six groups consisting of five rats each. Group A served as control. Groups B-D were given increasing oral doses (250, 500 and 1000 mg/kg body weight respectively) of Dacryodes edulis extract daily for two weeks prior to the administration of a single dose of CCl4 (3 ml/kg body weight) on the fourteenth day. Group E was given only Dacryodes edulis extract (1000 mg/kg body weight) daily for two weeks, while group F received only a single dose of CCl4 on day 14. The extract was found to possess hepatoprotective properties as seen in the significant (p < 0.05) reduction in the activities of the enzymes alanine transaminase, aspartate transaminase and alkaline phosphatase in the plasma of the animals treated with the plant extract when compared to the group administered CCl4 only. The extract also inhibited cholesterol and triacylglycerol accumulation in the liver. The hepatoprotective properties of Dacryodes edulis observed in this study may be related to its high content of antioxidant compounds such as flavonoids and alkaloids previously reported. The study represents a novel attempt at exploring the medicinal potential of the seeds of D. edulis which are typically discarded after eating the fleshy pulp.Key words: Dacryodes edulis, CCl4, Triacylglycerols, Hepatotoxicity, Steatosis

Geochemistry of Fluvial Sediments from Geregu, Southwest Nigeria

Geochemical analysis of fluvial sediments on the banks of River Ero using inductively coupled plasma mass spectrometry illustrates their maturity, provenance and tectonic setting. The analysed sediment samples show low SiO2/Al2O3 ratios of 2.92-2.99 (units FL_A, FL_B and FL_E) and high SiO2/Al2O3 ratios of 4.064-4.852 (units FL_C, FL_D, FL_F and FL_G). Sediments were geochemically classified as shales (units FL_A, FL_B and FL_E) and greywackes (units FL_C, FL_D, FL_F and FL_G). Variability in sediment maturity (FL_F > FL_G >FL_C >FL_D >FL_A > FL_B > FL_E) parallels a decreasing order in the ratios of SiO2/Al2O3 and K2O/Al2O3, as well as the proportion of quartz grains and matrix components. Evidence from Al2O3/TiO2, K2O, Rb, La/Co, Th/Co, Cr/ Th, Th/Cr, La/Th-Hf, Th-Hf-Co and rare earth element contents of sediment samples suggest felsic protoliths of upper continental crust in a passive margin tectonic setting. An insignificant contribution of mafic components from the source is, however, inferred based on the Ni and Cr contents of the sediment samples. Combined Eu anomalies <0.85 and (Gd/Yb)n ratios <2.0 (1.53- 1.82, average 1.65) suggest post-Archean protoliths

Petrographic and geochemical study of the Maastrichtian Ajali Sandstone, North Central Nigeria

he Upper Cretaceous Ajali Sandstone is an extensive stratigraphic unit of the Anambra Basin in southern Nigeria. It consists of friable, white cross-bedded sandstones exhibiting a fining upward sequence. Structures such as bioturbation, planar and herringbone cross beds indicate variability in depositional environment ranging from fluviatile to deltaic. Petrographic and geochemical compositions (major and trace elements) of these sandstones have been investigated to determine their provenance, tectonic setting and weathering conditions. Fifteen sandstone samples examined are rich in quartz but poor in feldspar and lithic fragments. Texturally, the framework grains of the sandstones are fine- to medium-grained, sub-angular to sub-rounded, moderately sorted to poorly sorted, positively skewed and leptokurtic. The sandstones are texturally immature as depicted by their sub-angular edges of grains, but mineralogically mature in terms of high percentage of quartz. The high chemical index of alteration (CIA) values (71.0–99.2%) for these sandstones suggests that they were derived from highly weathered rocks in the source area. The composition of the major oxides in the sandstones revealed that SiO2 (49.1–99.7%), Al2O3 (0.2–30.3%), Fe2O3 (0.4–1.8%) and TiO2 (0.06–3.2%) were the most abundant elements in all sandstone samples indicating a high detrital quartz and clay mineral content. The Al2O3/TiO2 ratios (1.47 to 12.48), Ti/Zr (6.48–18.63) and Zr/Cr (2.24–22.36) suggest that the sandstones were derived from variable basement complex rocks, including some contribution from mafic or ultramafic components. Inferences from the plots of K2O/Na2O versus SiO2 indicated a passive margin tectonic setting for the sandstones. The high loading of CaO and Na2O in more than 50% of the samples is indicative of terrigenous input, mainly in the form of carbonates and silicates. These results are generally consistent with a derivation of the sandstones from adjacent igneous and metamorphic basement complexes (Cameroon–Adamawa highlands and Oban Massif) while the extensive and blanket-like geometry of the Ajali Sandstone is indicative of an excellent reservoir for groundwater in the Anambra Basin