12 research outputs found
Petroleum contamination of Sombreiro River in Akuku-Toru Local Government Area Rivers State, Nigeria, revealed by Chemical Fingerprinting of Aliphatic Hydrocarbons
Water samples were collected from the lower section of Sombreiro River in Akuku Toru local government area (L.G.A.) of Rivers State, Nigeria and analyzed for aliphatic hydrocarbons using gas chromatographyflame ionization detector (GC-FID) after extraction and clean up. GC identified well resolved aliphatic hydrocarbons from C9 to C40 which showed similar bimodal n-alkane distributions and unresolved complex mixtures (UCM). Pristane was observed as the most prominent aliphatic hydrocarbon and dominant over phytane in all the samples. Common aliphatic hydrocarbon diagnostic ratios used for fingerprinting and interpreting chemical data were determined. These include carbon preference index (CPI) from 0.70 to 0.82; Pr/Ph from 1.85 - 2.17; Pr/nC17 from 1.67 - 1.87; Ph/nC18 from 0.94 - 1.07 and cross plot.The results reveal the following: (1) crude oil contamination of the lower section of Sombreiro river in Akuku Toru L.G.A. of Rivers State; (2) the same crude oil spilled in the river; (3) the spilled oil is Niger Delta in origin, derived from mixed marine and terrigenous organic matter deposited in an oxic environment; (4) the spilled oil was slightly degraded, its chemical composition has not undergone significant alteration.Keywords: Petroleum, Aliphatic hydrocarbon; Gas chromatography, Fingerprinting, Correlation
Acute Toxicity of Xylene on the African Catfish Clarias gariepinus
Acute toxicity of xylene on an African catfish (Clarias gariepinus) was carried out. A total of 210 catfish C. gariepinus juveniles with mean length 15.20±2.3cm, and mean weight of 10.23±2.6g were obtained from the University of Port Harcourt Demonstration Farm. The test was determined for 96hour median lethal concentration using concentrations of 250ml/l, 200ml/l, 150ml/l, 100ml/l, 50ml/l, 25ml/l and 0.0ml/l (control) which gave a LC50 value of 63.965ml/l with upper and lower confidence limits at 106.53 ml/l and 37.82ml/l respectively. The median lethal time LT50 recorded was 55.7 hours. There was a strong correlation between (%) mortality in Probits and the Log10 Dose (R²=0.9772). There was statistical significance (P>0.05) in the number of mortality observed in the six concentrations from 24 hours to 96 hours of exposure and high percentage mortalities were recorded as the concentration of the toxicant increased. No mortalities were recorded in the control. The cumulative mortality recorded after exposure of C. gariepinus to xylene was time dependent. Based on this the high percentage mortalities of the fish species it is therefore recommended that the use of this chemical be minimized and proper contingency plans be carried out before discharging this toxicants into the aquatic environment. Waste from this chemical and spill incidences should be detoxified to a less toxic level before disposing into the aquatic environment. The results obtained may provide valuable information for formulation of environmental policies and serve as a model for bio-monitoring of the aquatic environment.Keywords: Acute toxicity, Clarias gariepinus, and Xylene
Trace Metals and Volatile Aromatic Hydrocarbon Content of Ukpeliede-I Oil Spillage Site, Niger Delta, Nigeria
The composition and distribution of the volatile aromatic components:
Benzene, Toluene, Ethylbenzene, Xylene (BTEX) and the variations in the
concentration of the trace metals within the sampling interval of two
months and five months were studied in an oil impacted soil at
Ukpeliede in the Niger Delta area, Nigeria. This was done with a view
to assessing the level of attenuation of this particular group of crude
hydrocarbons and the changes /effects of some trace metals in the
impacted soils. The aromatic hydrocarbon levels were all above the
target level of 0.05mg/kg after two months post impact period. There
was a complete disappearance of the BTEX after the second sampling
interval of five months, paralleling a marked reduction of about 71% in
the concentration of zinc within the same sampling period suggesting a
common attenuation process or conditions.@ JASE
Biodiversity Conservation Effort and Livelihoods in Parts of Ilaje Riparian Community in Ondo State, Nigeria
Biodiversity constitute the resource base of human survival and economic well-being of immediate and future generations. It can be described as the diversity of life forms on Earth, variety of all living things, the places they inhabit, and the ecological interaction between them. This concept has been examined by several scientist and conservationist and with several studies on coastal ecosystem, its biodiversity scenarios, conservation priorities and sustainable livelihood been reported in parts of Niger Delta. However, this study is of high significance hence neither of these studies nor similar research on biodiversity conservation in coastal environment has been carried out in parts of Ilaje in Ondo State. The aim of the study was to evaluate the coastal biodiversity scenarios, livelihood and conservation efforts in Ileja. The gradient – directed transect sampling and Wetland Ecosystem Dynamic Plot (WEDP) method, Participatory Rapid Appraisal (PRA) and direct observational and ground-truthing by hand-held geographic positioning system (GPS - Garmin Dakota 10 model) for data collection were adapted. Data analysis was by descriptive analytical tools (frequency count, percentages and charts and levels of response anchors using the Likert –Type scale 7 point level of agreement and 5 point level of agreement). Result of biodiversity awareness of natural resources was high for the fishes; with 84% awareness in Odonla, Molutehin and Odun-Igo respectively; 88% in Ikorigho and 92% in Awoye. The least known resources include: Pig, Mudskipper, and Tortoise respectively with 4% awareness in Odonla, 4% of Snail in Molutehin, and 8% for Cray fish and Periwinkle respectively in Odun-Igo and Awoye. The level of awareness for community protection effort was 24% in Ikorigho and Odun-Igo respectively and 44% in Awoye. Government protection effort (36%) Odonla and (76%) Molutehin. The respondents choice for government effort than traditional effort in flora (mangrove) protection were 88%, 56%, 100%, 84% and 48% in Odonla, Ikorigho, Molutehin, Odun-Igo, and Awoye respectively. Sacred groves recorded 16%, 76% 92% and 68% presence in Ikorigho, Molutehin, Odun-Igo and Awoye respectively. Conclusively, it can be highlighted that the condition of the coastal biodiversity scenarios of Ilaje can be assessed as this may assist the government in executing the legislation at its disposal. Keywords: Ilaje, natural resources, government, tradition, biodiversity DOI: 10.7176/JESD/13-16-03 Publication date:August 31st 202
Geochemical Implication of some Chemical Fossils as Indicators of Petroleum Source Rocks
Chemical fossils (biomarkers) are molecules in crude oils, source rocks
and sediments whose carbon structures or skeletons can be traced back
to living organisms. Three of such diagnostic fossils have been
typically reviewed with respect to maturation changes,
precursor-product relationship, utility for source rock/crude oil,
crude oil/crude oil correlations and role in basin development.
Fingerprints (composition and distribution) of hopanes, oleananes and
steranes have been highlighted. Defunctionalization and breakage of
double bonds which occur during diagenesis as well as stereochemical
changes which occur during catagenesis have also been highlighted.
Napthenic hydrocarbons, such as steranes (C27 - C29) and triterpanes
(C29 - C32), are useful in geochemical correlations because of their
unique compound distributions and the fact that they are not seriously
affected by migration, thermal alteration and biodegradation. Although
individual biomarkers are in concentrations of only 10 to 200 ppm in
crude oils, they can be accurately measured in spite of their unusual
complexity and variety which find use in source rock correlation and
maturation studies. Correlations using chemical fossil technology can
be applied in real cases by recognizing the source chromatogram (GC) or
fragmentogram of the hydrocarbon molecules in the oils to know whether
they have the same biomarkers or similar geohistory of origin and
migration. Therefore, genetically related oils are differentiated from
unrelated oils on the assumption that the same source material and
environment of deposition produce the same oil. Thus, a chemical fossil
compound in a particular source rock would be expected to appear in the
oils it generated. @JASE
An Infrared Spectroscopic Evaluation of the Petroleum Potentials of Some Oil Shale From Lokpanta in the Lower Benue Trough of Nigeria
The kerogen of thirty randomly sampled outcrops of Lokpanta oil shales in the Lower Benue trough of Nigeria was extracted, isolated and characterized by infra-red {IR} spectroscopy. Quantitative assessment of the kerogen concentrates was made and correlated with the total organic carbon content {TOC} of source rocks The isolated kerogen concentrates were found to have a mean weight [ + standard deviation] of 3.86 + 0.84% of the dry rock sample. Analysis of the IR spectra was carried out both qualitatively and semi-quantitatively. Extrapolations from structural elucidation revealed that the Lokpanta facies contained few mono-aromatics and cyclohexyl rings. The spectra variously showed good correlations in the 1600cm-1, 1450cm-1 and 2900cm-1 peak areas. Deduction from results show that although kerogen concentrates varied from 0.76% to 11.06%, over 50% of the sampled outcrops had a percent weight > 2.5% which is the lower limit proposed for mature, oil - and gas - generating organic matter. © JASE
An Infrared Spectroscopic Evaluation of the Petroleum Potentials of Some Oil Shale From Lokpanta in the Lower Benue Trough of Nigeria
The kerogen of thirty randomly sampled outcrops of Lokpanta oil shales in the Lower Benue trough of Nigeria was extracted, isolated and characterized by infra-red {IR} spectroscopy. Quantitative assessment of the kerogen concentrates was made and correlated with the total organic carbon content {TOC} of source rocks The isolated kerogen concentrates were found to have a mean weight [ + standard deviation] of 3.86 + 0.84% of the dry rock sample. Analysis of the IR spectra was carried out both qualitatively and semi-quantitatively. Extrapolations from structural elucidation revealed that the Lokpanta facies contained few mono-aromatics and cyclohexyl rings. The spectra variously showed good correlations in the 1600cm-1, 1450cm-1 and 2900cm-1 peak areas. Deduction from results show that although kerogen concentrates varied from 0.76% to 11.06%, over 50% of the sampled outcrops had a percent weight > 2.5% which is the lower limit proposed for mature, oil - and gas - generating organic matter.
(Journal of Applied Sciences & Environmental Management: 2002 6(1): 34-38
Cadmium uptake by Telfaria Occidentalis Hook F.(cucurbitaceae) grown in cadmiun-polluted soil
Five seedlings of locally purchased Telfairia occidentalis Hook f. (fluted pumpkin) were cultivated in cadmium polluted soils. Leaves of the plant were plucked after 5 weeks of growth from five replicate treatments and an untreated control. These leaves were air-dried, digested and analyzed spectrophotometrically for cadmium. Fifty milligrams per litre (50mg/l) dilution of stock solution of cadmium had mean level of accumulation ( S. E.) of 2.28 1.49 mg/kg while 15 mg/L and 4.5 mg/L gave cadmium levels of 1.96 1.60 mg/kg and 1.25 0.01 mg/kg respectively. Crude protein yields of 86.66 3.30 mg/kg, 87.70 1.89 mg/kg and 88.89 1.93 mg/kg were obtained for the replicate treatments of 50mg/L and 4.5mg/L cadmium respectively. Anova tests showed that the differences between cadmium levels accumulated for control and treatment plants were significant (no overlap in standard error) at 5% level of probability. There were no such significant differences (P 0.05) for the amount of crude protein yields when the control was compared to the treatments. T. occidentalis therefore poses a threat of cadmium poisoning to the population of the Niger Delta Area where the vegetable is commonly grown and consumed.
Keywords: polluted soils, Cadmium, Anova Test, Niger Delta, T. Occidentials.
(Global Journal of Pure and Applied Sciences: 2002 8(4): 497-500
Concentration of heavy metals and petroleum hydrocarbons in previously remediated sites in Niger Delta, Nigeria
This study was aimed at assessing the soil conditions of previously remediated oil spill sites in the Niger Delta region. Ninety-six (96) soil samples were collected over two seasons from remediated sites from three states (Rivers, Abia, and Imo). Gas Chromatographic (GC) Analysis was used in analyzing for Total Petroleum Hydrocarbon (TPH) content while heavy metals analysis for Lead (Pb), Zinc (Zn), Copper (Cu), Chromium (Cr) and Iron (Fe) was done using absorptive spectrophotometric analyses. The data generated was subjected to ANOVA and multiple comparisons, Post-Hoc Tukey HSD test using IBM SPSS version 26.0. Results showed TPH range of 0.85±0.72mg/kg to 1.76±0.42mg/kg in samples from Owaza site in Abia state. Concentration of heavy metals in soil samples was below the standard permissible levels of the World Health Organization and other regulatory bodies such as Department of Petroleum Resources (DPR) intervention values, United States Environmental Protection Agency (USEPA), and Environmental Guidelines and Standards for Petroleum Industry in Nigeria (EGASPIN 2002), accepted values for soil samples. There were no effects of season variation observed. Enrichment factor of (323.20- 508.64) and (298.37-567.26) indicates anthropogenic activities as sources of pollution. The result of the current studies signifies that, the soils of previously remediated sites have safe levels of the contaminants; however, werecommended a regular routine check on the levels of contaminants
Quantal response of Lumbricus terrestis from two oil spillage - prone sites to toxicity of Bonny Light crude oil.
Test fauna, Lumbricus terrestis, were obtained from two oil spillage-prone sites in Rivers State, Nigeria and were treated with varying concentrations of Bonny Light crude oil with known physico-chemical properties to determine the "all or none" response of the Lumbricus terrestis to lethal doses of the test compound.
Data based on quantal response (mortality) were subjected to probit analysis using the Standard Probability Scale of three-cycle logarithm (AP-0573-GT). Toxicity Index, LC50 (median lethal concentration) of 74.14ml/L and 17.82ml/L of Bonny Light were obtained after 48 and 96 hours respectively for animals from Ogbodo-Isiokpo while 70.79ml/L and 16.98ml/L of Bonny Light were obtained after 48 and 96 hours respectively for animals from Eneka. These results imply that such concentrations of Bonny Light crude oil would be lethal to 50% of the population density of Lumbricus terrestis within the fixed periods of 48 and 96 hours respectively. One of its major highlights is the decrease in the values of LC50 with time of exposure (24 hours - 96 hours). Expectedly, higher exposure periods to the crude oil might have induced more toxicity. LC50 after 24 hours was not possibly determined because no mortality was recorded for animals exposed to the test compound within the fixed period of 24 hours.
Key words: crude oil, test fauna, toxicity index, quantal response, oil spillage prone sites.
[Global Jnl Environ Sci Vol.1(1) 2002: 59-64