Earthworm-assisted bioremediation of petroleum hydrocarbon contaminated soil from mechanic workshop

The use of earthworms (Eudrilus eugenia) for vermi-assisted bioremediation of petroleum hydrocarbon contaminated mechanic workshop soils was investigated. Parameters of interest where earthworm survival, microbial count and identification, carbon and nitrogen contents of the soil and total petroleum hydrocarbon content of the soil. Earthworm survival was found to be dependent on the concentration of petroleum hydrocarbon and nature of the mechanic workshop. The survival of the worms in the as-obtained mechanic workshop soil was much lower than the survival in mechanic workshop soil diluted with petroleum hydrocarbon free soil. Earthworm inoculation also resulted in lower soil C and N contents after 35 days of vermi-assisted bioremediation. After 35 days of treatment, earthworm inoculation effected a higher drop in total petroleum hydrocarbon contents as compared to the samples without worms, indicating that earthworms may be used as biocatalysts in the bioremediation process.Key words: Eudrilus eugeniae, total petroleum hydrocarbon, mechanic workshop soil

Heavy metal contamination of soil in mechanic workshops

The distribution of metal in soil from mechanic workshops around Zaria, Nigeria (Latitude: 11° 4' 0 N, Longitude: 7° 42' 0 E) was studied. The types of mechanic workshops considered were motorcycle, motorcar, truck/lorries and generator set. The soils were sampled in August 2010. The results indicated that there was an increase in the metal content of soil in all types of mechanic workshops. The heavy metal (nickel, copper, zinc, lead and arsenic) content of the soil was compared with recommended limits. The percentage composition of some of the heavy metals, in many of the samples, were found to be in excess of the considered set limit, particularly for lead for which the percentage of soil samples analyzed from motorcycle, motorcar, truck/lories and generator set mechanic workshops in excess of the considered recommended set limit was found to be 88.89, 100, 100 and 100% respectively. 11.1% of all the samples analyzed were found to contain arsenic in excess of recommended limit. Statistical analysis of the heavy metal content (one-way analysis of variance) indicated that the Zn and Pb contents of soil from mechanic workshops were not functions of the workshop type (P > 0.05) but the nickel and copper contents were found to be dependent on workshop type (P < 0.05).Keywords: Elemental analysis, Heavy metals, Mechanic workshop, Soil, Zari

Synthesis and characterization of antiseptic soap from neem oil and shea butter oil

In this work, neem oil and shea butter oil were mixed in various proportions and used in preparing soaps which were subsequently characterized. The combination of Neem oil to Shea butter oil considered were 100:0, 80:20, 60:40, 50:50, 40:60, 20:80 and 0:100 (wt:wt). The physical properties of the prepared soap including hardness, foamability and pH were analyzed. The antibacterial properties of the prepared soaps in terms of sensitivity, minimum inhibitory concentration and minimum bactericidal concentration (with respect to Staphylococcus aureus and Bacillus subtilis) indicated that the optimal anti-bacterial property of the developed soap was obtained with the exclusive use of shea butter oil.Keywords: Neem oil, shea butter, antibacterial property.African Journal of Biotechnology Vol. 12(29), pp. 4656-466

Effect of earthworm inoculation on the bioremediation of used engine oil contaminated soil

The effect of earthworm (Eudrilus eugeniae) on the bioremediation of used engine oil contaminated soil, amended with poultry manure, was investigated. Investigation into the effect of initial concentration of used engine oil, in soil, for earthworm inoculated samples showed that the biodegradation rate of used engine oil contaminant increased with increasing initial concentration of used engine oil. For initial used engine oil concentration of 5, 10, 15 and 20 g/kg soil, the drop in total petroleum hydrocarbon was found to be -16.91, 20.82, 34.68 and 36.28% respectively after 42 days of treatment. Investigation into the effect of earthworm concentration showed that the use of earthworms did not result in catalysis of the bioremediation process as the extent of biodegradation for the sample without earthworm was found to be higher than those of all concentrations of earthworm considered (5 - 20 worms/kg soil). However, the rate of bioremediation was found to increase with increase in earthworm concentration (as earthworm concentration was increased from 5 to 20 worms per kg of used engine oil contaminated soil). Similarly when the rate of bioremediation in the without-earthworm but manually tilled and the without-earthworm and untilled samples where compared with samples inoculated with earthworm for bioremediation, both samples without worms recorded higher bioremediation rates.Keywords: Concentration, Time, Total petroleum hydrocarbon, vermicomposting, Eudrilus eugenia

Extraction and characterization of chitin and chitosan from Nigerian shrimps

Chitin was synthesized from Nigerian brown shrimps by a chemical process involving demineralization and deproteinisation. Deacetylation of the chitin was conducted to obtain Chitosan. The chitin and chitosan were characterized using FTIR, XRD and SEM. Proximate and elemental analysis were also conducted. The percentage yield of chitin was 8.9%. The degree of deacetylation of chitin was found to be 50.64% which was a low value compared to previous works and can be attributed to the low alkali concentration and heating time. XRD patterns indicated that chitin was more crystalline than the corresponding chitosan. FTIR spectra indicated the presence of functional groups associated with different bands, the intensities and stretching established that the samples are chitin and chitosan. SEM analysis also indicated morphological differences between the chitin and chitosan.Keywords: Deacetylation, biodegradable, characterization, deproteinisation, demineralizatio

Phytochemical Screening and Antibacterial Activities of Aframomum melegueta (K. Schum) Seed Extracts on Salmonella typhi and Klebsiella pneumoniae

The phytochemical screening and antibacterial effects of Aframomum melegueta (K. Schum)on Salmonella typhi and Klebsiella pneumoniae was carried out. The phytochemical screening revealed the presence of alkaloids, flavonoids, tannins, saponins, steroids, anthraquinones, terpenoids, glycosides and phenols in the seed extract. The susceptibility test showedzones of inhibition (ZOI) of S. typhi (11.0mm) and K. pneumonia (13.0mm) with methanolic seed extract (MSE), while the hot aqueous seed extract (HASE) recorded 3.0mmas ZOI for both test organisms. The Minimum inhibitory concentration (MIC) of 200mg/ml and 100mg/ml were recorded against S. typhi and K. pneumoniae respectively with MSE, while HASE indicated 400mg/ml and 200mg/ml MICs against S. typhi and K. pneumoniae respectively. The Minimum Bactericidal Concentration (MBC) obtained from MSE were 200 mg/ml and 25mg/ml for S. typhiand K. pneumoniae, while HASE had > 400mg/ml for test microbes. The effectiveness of different concentrations of the test plant extracts on the test organisms was significant (P<0.05). Further trials involving other clinical isolates and botanicals at different concentrations be conducted, to optimize theprocess

A Systematic Review of African Studies on Intimate Partner Violence against Pregnant Women: Prevalence and Risk Factors

Background: Intimate partner violence (IPV) is very high in Africa. However, information obtained from the increasing number of African studies on IPV among pregnant women has not been scientifically analyzed. This paper presents a systematic review summing up the evidence from African studies on IPV prevalence and risk factors among pregnant women. Methods: A key-word defined search of various electronic databases, specific journals and reference lists on IPV prevalence and risk factors during pregnancy resulted in 19 peer-reviewed journal articles which matched our inclusion criteria. Quantitative articles about pregnant women from Africa published in English between 2000 and 2010 were reviewed. At least two reviewers assessed each paper for quality and content. We conducted meta-analysis of prevalence data and reported odds ratios of risk factors. Results: The prevalence of IPV during pregnancy ranges from 2% to 57% (n = 13 studies) with meta-analysis yielding an overall prevalence of 15.23% (95% CI: 14.38 to 16.08%). After adjustment for known confounders, five studies retained significant associations between HIV and IPV during pregnancy (OR1.48-3.10). Five studies demonstrated strong evidence that a history of violence is significantly associated with IPV in pregnancy and alcohol abuse by a partner also increases a woman's chances of being abused during pregnancy (OR 2.89-11.60). Other risk factors include risky sexual behaviours, low socioeconomic status and young age. Conclusion: The prevalence of IPV among pregnant women in Africa is one of the highest reported globally. The major risk factors included HIV infection, history of violence and alcohol and drug use. This evidence points to the importance of further research to both better understand IPV during pregnancy and feed into interventions in reproductive health services to prevent and minimize the impact of such violence