Assessment of ground water pollution in the residential areas of Ewekoro and Shagamu due to cement production

Chemical and physico–chemical parameters of ground water samples from wells were analyzed by multivariate statistical tools to provide the characterisation of the ground water distribution of the settlements around cement factories in Ewekoro and Shagamu, Ogun State in Nigeria. The 17 parameters determined include: pH, conductivity, dissolved oxygen (DO), total dissolved solids (TDS), biochemical oxygen demand (BOD), total hardness, acidity, and alkalinity; anions such as chlorides, sulphates, phosphates and nitrates as well as potentially toxic metals such as copper, lead, zinc, iron and cadmium. The analytical data were obtained from 6 wells in Ewekoro and 11 wells in Shagamu sampled during three different periods along a year covering both the wet, break and dry seasons of 2009. The concentrations of lead and cadmium are above the World Health Organisation (WHO) standard in all three seasons investigated with lead having as high as 1.05 mg/L and maximum of 0.068 mg/L for cadmium. It was also observed that the levels of sulphate was higher that the WHO standard during the dry season with a maximum concentration of 623 mg/L. All other physicochemical parameters fell within the permissible range as stipulated by the WHO. There was no seasonal difference in the concentrations of the potentially toxic metals analysed in the ground water from the two sites, while for the physicochemical properties, there was a seasonal variation in the results of the ground water quality in the two sites studied with DO having a p-value of 0.009, BOD with p-value of 0.04 and Alkalinity of 0.044 p-value. An approach for the characterisation of the groundwater system of the neighbourhood of the cement factories is proposed on the basis of its physico-chemical composition, in order to detect multivariate patterns for unpolluted waters as well as for eventual polluted zones.Key words: Toxic metals, physico-chemical composition, multivariate, cement, ground water

Comparison of extraction and clean-up techniques for the determination of polycyclic aromatic hydrocarbons in contaminated soil samples

The development of a fast, efficient and quantitative technique for the extraction, clean-up, and preconcentration of the 16 United States Environmental Protection Agency (USEPA) priority polycyclic aromatic hydrocarbons (PAHs) was carried out on contaminated soils. The effect of Soxhlet, ultrasonication and mechanical shaking used in the extraction of a low-level PAH soil certified reference material (CRM131-100) was investigated. Six different extraction solvents: acetone, cyclohexane, 2- propanol, methanol, acetonitrile and dichloromethane, were tested to select the most suitable solvent for the extraction of the 16 PAHs from the certified soil reference material. The results were compared to determine the method with the highest extraction efficiency. The clean up and preconcentration procedures for the PAHs were optimised using the solid phase extraction (SPE). Acetonitrile, dichloromethane and tetrahydrofuran were tested as eluants for the optimisation of SPE clean up. Chromatographic conditions for the separation of PAHs using High Performance Liquid Chromatography (HPLC) using UV-DAD and fluorimetric detection with programmed excitation and emission wavelengths were also optimised. The optimised ultrasonic extraction procedure and SPE clean-up extracted the PAHs from the certified reference material with recoveries ranging from 63.6 % to over 100%.Key words: High Performance Liquid Chromatography (HPLC), mechanical shaking, polycyclic aromatic hydrocarbons (PAHs), soil, solid phase extraction (SPE), soxhlet extraction, ultrasonication

Hybrid Energy Systems Model with the Inclusion of Energy Efficiency Measures: A Rural Application Perspective

way to the carbon footprint in the developing nations. Thus, the energy management initiative could assist in reducing the menace of greenhouse gas emission. Hence, the energy policy makers and planners have unanimously proposed adoption of demand side management (DSM) technique. Thus the adoption of energy efficiency technique (EET)-a DSM measures and hybrid energy system would be essential for rural electrification. This work investigates the effect of applying energy efficiency measures in rural electrification. A case study of an un-electrified rural settlement in Ibadan, Nigeria was considered. The utilization of EET techniques reduces the emission of CO2 by 62%, while the technical analysis indicates the possibility of a 100% renewable electricity production. Principally, the adoption of energy efficient techniques proved to be economically and environmentally friendly

Development of a Sludge Dewatering Filter and Utilization of Dried Sludge in Brick Making

These A dewatering filter was designed and constructed to dewater sludge collected from Eleyele waterworks using slow sand filtration. Washed sand passing through sieve mesh size of 1.18 mm was used as the filter media. The flow rate of the filtrate was monitored for six (6) days and readings were taken at 30-minute intervals for 6 hours after each sludge loading of 15 L. The dewatered and dried sludge was investigated for use as brick material. The sludge and laterite samples were characterized using Atomic Absorption Spectroscopy. The major chemical components of  the sludge and laterite samples were silicon, aluminium and iron oxides. The laterite soil sample consisted of 60.47% SiO2, 17.77% Al2O3 and 8.18% Fe2O3 while the sludge sample consisted of 52.98% SiO2, 29.46% Al2O3 and 3.63% Fe2O3. Batching method by weight was used in mixing the materials in the ratios of sludge at 0%, 15% and 30% to produce laboratory scale bricks with dimensions of 70 mm by 70 mm by 70 mm and the properties of the bricks were investigated. The average compressive strength of the laterite bricks with dried sludge content of 0%, 15% and 30% were 3.15 N/mm2, 3.08 N/mm2 and 2.64 N/mm2, respectively. The results of this research demonstrated that a locally constructed sludge dewatering filter can be used to thicken waterworks sludge and laterite-sludge can be made from dewatered water works sludge.Keywords—Compressive strength, bricks, filter, media slow sand filtration, waterworks sludg

Changes in antioxidant status associated with haemodialysis in chronic kidney disease

Oxidative stress has been implicated in the pathogenesis, progression of chronic kidney disease (CKD) and development of cardiovascular complications. Hemodialysis (HD) has also been described to contribute significantly to oxidative stress in CKD patients, though reports are conflicting.Objective: We evaluated the effects of one session of HD on the antioxidant capacity and lipid peroxidation in CKD patients.Method: Thirty-six CKD patients requiring HD were recruited into this study. Participants were naïve to HD and each completed a session of three hours using polysulfone membrane dialyzers. Blood samples were collected before and after dialysis. Total antioxidant capacity (TAC) was measured by ferric reducing antioxidant power (FRAP) while malondialdehyde (MDA) was measured using thiobarbituric acid-reactive substance (TBARS). Comparison was made between pre-HD and post-HD values of TAC and MDA respectively, p value of <0.05 was taken as significant.Result: Mean age and estimated glomerular filtration rate of subjects were 45 ±15 years and 6.3± 4.7mls/1.73m2 respectively. There was significant decrease in the mean TAC from 1232.2 ± 495.6 μmol Trolox equiv/ to 832.4 ±325.7 μmol Trolox equiv/L post-dialysis (p< 0.001) while MDA values were similar before and after HD (11.8 ± 1.8 vs 11.8 ± 2.331)μmol/L (p> 0.05). There was no significant association between changes in antioxidant status following HD with blood flow rate, ultrafiltration volume nor dialyzer per size.Conclusion: A session of HD in patients with CKD is associated with significant reduction of the total antioxidants capacity; and no effect on MDA levels.Funding: No external funding receivedKeywords: oxidative stress, antioxidants capacity, hemodialysis, chronic kidney diseas

Seroprevalence of hepatitis E among restaurant food handlers in Ibadan, Nigeria

 Background: Hepatitis E virus (HEV) is one of the causative agent of acute viral hepatitis in humans. HEV is an important public health disease in many parts of the world because it is transmitted faeco-orally.  Majority of the documented studies on hepatitis E virus in Nigeria have focused on pregnant women and animal handlers with limited data among food handlers. Thus the current study aimed at investigating the prevalence of HEV infection among food handlers operating within the premises of a tertiary care facility.Methods: One hundred and seventy seven (177) food handlers were screened using commercial Enzyme-Linked Immuno-Sorbent Assay (ELISA) to detect IgM antibodies to Hepatitis E. A semi-structured questionnaire was used to assess risk factors for HEV infection.Results: HEV IgM antibodies were detected in 16 (9.0%) of the participants. Age-specific HEV IgM seroprevalence appeared to decrease with age, however there were no significant differences in HEV IgM seropositivity regarding age (P=0.251), gender (P = 0.231), marital status (P=0.735) and religion (P = 0.906). Significant risk factors for HEV IgM seropositivity included source of water for drinking (P=0.03) and the use of soap for hand washing (P=0.02).Conclusion: Our findings suggest that HEV remains a public health problem, as the virus circulates at low but considerable levels especially among food handlers; thus posing a threat to potential contacts. Proper hand washing practices as well as provision of portable water are important factors for the control of Hepatitis E

Antioxidant and DPPH-Scavenging Activities of Compounds and Ethanolic Extract of the Leaf and Twigs of Caesalpinia bonduc L. Roxb.

Antioxidant effects of ethanolic extract of Caesalpinia bonduc and its isolated bioactive compounds were evaluated in vitro. The compounds included two new cassanediterpenes, 1α,7α-diacetoxy-5α,6β-dihydroxyl-cass-14(15)-epoxy-16,12-olide (1)and 12α-ethoxyl-1α,14β-diacetoxy-2α,5α-dihydroxyl cass-13(15)-en-16,12-olide(2); and others, bonducellin (3), 7,4’-dihydroxy-3,11-dehydrohomoisoflavanone (4), daucosterol (5), luteolin (6), quercetin-3-methyl ether (7) and kaempferol-3-O-α-L-rhamnopyranosyl-(1Ç2)-β-D-xylopyranoside (8). The antioxidant properties of the extract and compounds were assessed by the measurement of the total phenolic content, ascorbic acid content, total antioxidant capacity and 1-1-diphenyl-2-picryl hydrazyl (DPPH) and hydrogen peroxide radicals scavenging activities.Compounds 3, 6, 7 and ethanolic extract had DPPH scavenging activities with IC50 values of 186, 75, 17 and 102 μg/ml respectively when compared to vitamin C with 15 μg/ml. On the other hand, no significant results were obtained for hydrogen peroxide radical. In addition, compound 7 has the highest phenolic content of 0.81±0.01 mg/ml of gallic acid equivalent while compound 8 showed the highest total antioxidant capacity with 254.31±3.54 and 199.82±2.78 μg/ml gallic and ascorbic acid equivalent respectively. Compound 4 and ethanolic extract showed a high ascorbic acid content of 2.26±0.01 and 6.78±0.03 mg/ml respectively.The results obtained showed the antioxidant activity of the ethanolic extract of C. bonduc and deduced that this activity was mediated by its isolated bioactive compounds

Soil Contamination and Risk Assessments on Selected Dumpsites within the Basement Complex and Sedimentary Formations of Ogun State, South-western Nigeria

The concentrations of inorganic elements in soils of Saje, Ita-Oshin, Premier, and Oke-Diya dumpsites were determined using an X-Ray Fluorescence spectrometer to assess the soil quality through chronological changes with depths. A soil core sampler collects 56 samples at 20, 40, 60, and 80 cm depths. Saje showed high mean concentrations of Ca, K, Fe, Rb, and Ti at all depths, while Oke-Diya revealed high mean concentrations of Ca, K, Fe, Rb, Ti, Mn, Zn, V, Cr, and Ni at all depths. These concentrations were in a closed range suggesting a build-up of elements in the soil profiles. Oke-Diya had the highest pollution index, followed by Saje, and the contaminations were from anthropogenic and geologic sources. The mean concentrations of Fe, Zn, Ni, Mn, Ti, K, and Ca were high at all depths in Ita-Oshin, and in Premier, the mean concentrations of K and Fe were high at all depths. Premier had the lowest pollution index. Ita-Oshin and Premier enrichment factors showed geologic sources. Saje and Oke-Diya revealed unacceptable non-carcinogenic risks for adults and children, and Ita-Oshin and Premier recorded acceptable limits. Saje and Oke-Diya samples had high carcinogenic risks for adults due to Cr, Pb, and As. Elements Cr and As in Ita-Oshin, and Pb in Premier evinced unacceptable carcinogenic risks for adults. Saje, Oke-Diya, and Premier indicated unacceptable carcinogenic risks for children due to Cr. The study showed toxins build-up in the soil system, and the study areas are not suitable for growing crops and sinking water wells for agricultural and domestic uses

Observation and Modeling of the Solar Transition Region: II. Solutions of the Quasi-Static Loop Model

In the present work we undertake a study of the quasi-static loop model and the observational consequences of the various solutions found. We obtain the most general solutions consistent with certain initial conditions. Great care is exercised in choosing these conditions to be physically plausible (motivated by observations). We show that the assumptions of previous quasi-static loop models, such as the models of Rosner, Tucker and Vaiana (1978) and Veseckey, Antiochos and Underwood (1979), are not necessarily valid for small loops at transition region temperatures. We find three general classes of solutions for the quasi-static loop model, which we denote, radiation dominated loops, conduction dominated loops and classical loops. These solutions are then compared with observations. Departures from the classical scaling law of RTV are found for the solutions obtained. It is shown that loops of the type that we model here can make a significant contribution to lower transition region emission via thermal conduction from the upper transition region.Comment: 30 pages, 3 figures, Submitted to ApJ, Microsoft Word File 6.0/9

Ethanolic extract of Jatropha gossypifolia exacerbates Potassium Bromate-induced clastogenicity, hepatotoxicity, and lipid peroxidation in rats

Extracts of J. gossypifolia L. have been reported to have several medicinal values, including potential anti-cancer and anti-inflammatory properties. In this study, we investigated the anti-clastogenic and hepatoprotective, effects of the ethanolic leaf extract of J. gossypifolia L. in potassium bromate (KBrO3)-induced toxicity in rats. The general trend of the results indicates significant increases (p < 0.05) in mean values when toxicant (KBrO3) only group is compared with normal control group, except for catalase where a significant decrease (p < 0.05) was recorded. Surprisingly, treatment of the toxic effects of KBrO3 by J. gossypifolia did not lower the mean values of any of these parameters investigated. Instead, there were significant increases (p < 0.05) in the mean number of bone marrow micronucleated polychromatic erythrocytes (mPCEs), plasma malondialdehyde (MDA) concentration, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and gamma glutamyl transferase activities, and sodium, while the increases in mean concentrations of creatinine, urea, and potassium were not significant (p > 0.05). Also, there was a further reduction in the activity of catalase by J. gossypifolia treatment, and was also not significant (p > 0.05). We therefore concluded that the ethanolic leaf extract of J. gossypifolia may not have a protective role against chromosomal and liver damage in KBrO3-induced toxicity, but complicating effects.Keywords: Jatropha gossypifolia, KBrO3, ethanolic extract, toxicity, rat