scholarly journals CRUDE OIL TOXICITY TOLERANCE OF HYDROCARBONOCLASTIC STRAIN OF CITROBACTER AMALONATICUS -Y2ESW1 ISOLATED FROM ESTUARINE SEDIMENT IN THE NIGER DELTA OF NIGERIA

2020 ◽  
Vol 10 (3) ◽  
pp. 413-417
Author(s):  
Abigail Nkanang
2020 ◽  
pp. 21-34
Author(s):  
Uche-Chinemere NWAOZUZU ◽  
Ifeanyichukwu ABADA ◽  
Emeka ANIAGO

This study presents an interdisciplinary approach towards a critical analysis of some impacts of crude-oil exploration in Niger Delta and polemics of viable conϐlict resolution framework. This approach involves analysis of Ahmed Yerima’s creative portrayal in Hard Ground which revolves around the variables activating conϐlicting emotional interests in matters concerning ‘black gold’ in Nigeria, and how these variables resonant in debates and demands for Nigeria’s polity restructuring because of perceived resource mismanagement. More so, our scope includes an analytical attempt at illuminating elaborately our interpretation of the dimensions to the loud and shrewd inclinations subsuming what some see as solution to the lingering conϐlict, and the suppositions explaining why others see the debates and demands on polity restructuring as dark convoluted ploys aimed at hidden agenda. Hence, through select theories of victimhood, this study attempts to elucidate on the variables propelling conϐlicting emotional interestsabout oil exploration in Niger Delta, by looking interpretively hard and deep on the perspectives, views and suppositions deϐining the ideologies and inclinations propelling them. In the end, this study notes that the disenchantments and troubles with Nigeria’s polity framework and structure as it relates to oil exploration in Niger Delta are subsumed in Hard Ground’s creativecontribution as a means of assessing the points to the fault-lines that characterize the subsisting socio-political structure upon which Nigeria stands and wobbles.


1975 ◽  
Vol 10 (1) ◽  
pp. 73-83
Author(s):  
J.E.S. Graham ◽  
T.C. Hutchinson

Abstract Crude oil spills are increasingly likely to occur from drilling, pumping and transportation activities as oil development proceeds at a rapid pace. These spills may occur over the wide range of climatic conditions which obtain in Canada. Little is known of oil toxicity at different temperatures; consequently, laboratory studies were made of the variability of the toxicity of aqueous extracts of a Norman Wells crude oil to freshwater algae over the temperature range 5°C to 35°C. Two unicellular green algae were studied: Chlamydomonas eugametos and Chlorella vulgaris. Their response (measured by cell numbers) varied with temperature and species. Whereas Chlamydomonas eugametos showed a general pattern of growth inhibition by oil at all temperatures with maximum inhibition at 25°C, Chlorella vulgaris showed general growth stimulation by oil with maximum stimulation at 25°C, this temperature was chosen for all further experimentation. All experiments were done using unialgal cultures and sterile technique. Cells were grown in 50 ml of nutrient medium (BBM) in 125 ml Erlenmeyer flasks. Such flasks allow gas exchange and permit loss of volatile hydrocarbons. Aqueous extracts were made by slowly stirring 5% crude oil with the nutrient medium for six hours using a magnetic mixer. The extract was then allowed to sit for two to four hours before the lower fraction was drawn off for use. Experiments were carried out in controlled environment chambers (±2°C) with a twelve hour light-dark cycle. All further experiments used a similar methodology. (Note: Chlamydomonas eugametos experiments were carried out on a rotary shaker at 125 rpm.) An attempt was made to determine the reason for the remarkable stimulation in growth of Chlorella vulgaris #29 at 25°C. This organism has been described in the literature as heterotrophic. Thus three reasons for stimulation seemed possible: 1. heterotrophic uptake of hydrocarbons directly from solution; 2. heterotrophic uptake of organic compounds formed or released by microbial breakdown of hydrocarbons (the aqueous extract of crude was not sterile); or 3. the use of CO2 released to solution by microbial respiration. The original experiment was repeated in the dark at 20°C to determine if stimulation still occurred. It did not, since cells exposed to the aqueous extract decreased in numbers. However, after two weeks the cells were illuminated and even though experimental flasks started off with depleted populations, they outgrew the control cells within two weeks. This suggested that if stimulation was related to heterotrophism, it must, at least in this case, have been the unusual case of photoheterotrophism. The reasons for this stimulation of growth are currently under investigation. Several methods are being employed to investigate the suspected heterotrophism. Experiments will be done to determine whether light energy is essential to the stimulation. Two varieties of Chlorella vulgaris, i.e. #29 and #260 are heterotrophic and autotrophic respectively, are to be used in experiments. Sterile aqueous extracts made by pressure ultrafiltration will be used. These experiments should determine whether algal growth stimulation is related to heterotrophism or whether microbial degradation of hydrocarbons is the real source of stimulation. Although the toxicity of crude oil may be rapidly ameliorated by physical and/or biological phenomena, one must still be aware of the possibility of a large input of organic carbon causing extensive eutrophication. Thus both toxicity and eutrophication will cause a selection, in terms of survival, in a natural environment. It is evident that although an oil spill may not totally destroy an ecosystem, it will certainly alter its natural composition considerably.


2021 ◽  
Vol 757 ◽  
pp. 143896
Author(s):  
Elin Sørhus ◽  
Carey E. Donald ◽  
Denis da Silva ◽  
Anders Thorsen ◽  
Ørjan Karlsen ◽  
...  

2021 ◽  
Author(s):  
Bjørn Henrik Hansen ◽  
Trond Nordtug ◽  
Ida Beathe Øverjordet ◽  
Dag Altin ◽  
Julia Farkas ◽  
...  

2021 ◽  
Vol 20 (1) ◽  
pp. 109-124
Author(s):  
V.C Wokem ◽  
E.D. Momoh

The exploration, production and refining of crude oil has led to severe environmental degradation in the oil producing communities of the Niger Delta region of Nigeria. Enhanced bioremediation of tropical rainforest soil artificially polluted with crude oil, bioaugmented with nitrogen fixing bacteria (NFB) and biostimulated with poultry droppings was carried out ex situ. Soil sample was collected at 15cm depth from tropical rainforest soil of the University of Port Harcourt, Nigeria. The NFB was isolated from roots of leguminous plant Arachis hypogea, identified as Nitrobacter species. Bioaugmentation by application of NFB served as option A, option B (biostimulation by application of poultry droppings), option C (No amendment) served as the control. Bioremediation was monitored for 28 days for interval of 14 days, and determined using the percentage ratio of total petroleum hydrocarbon (TPH) losses for each period to TPH at initial day (day zero). Results of total culturable heterotrophic bacterial (TCHB) counts showed that highest range in option B (1.9×104- 2.4×109Cfu/g) than in option A (7.8×106 -2.29×107Cfu/g) and C (6.75×106 -2.6×107Cfu/g) respectively. Similarly, hydrocarbon utilizing bacterial (HUB) counts had higher range in option B (1.20×105 - 1.9×107Cfu/g) than in option A (8.30×104 - 2.30×105Cfu/g) and option C control (4.3×104 −1.69×105 Cfu/g) respectively. Changes in physicochemical parameters during the study showed reductions in nitrate, phosphate and TPH in all the options expect pH which showed slight increase in option C (6.20-6.24). Characterization and identification for bacteria revealed the following HUB genera Pseudomonas, Citrobacter, Bacillus, Corynebacterium, Micrococcus, Klebsiella, Staphylocuccus and Nitrobacter). The percentage losses in TPH from gas chromatography (GC) results showed the following; option A (44.24%) option B (61.08%) and option C - control (27.28%) respectively. The results from this study showed that option B, the application of poultry droppings as biostimulant was more efficient than the application of NFB in enhanced bioremediation of crude oil polluted soil, hence the use of poultry droppings which is available as organic waste, eco-friendly and cost-effective is recommended asbiostimulant for enhanced bioremediation in environmental cleanup of crude oil impacted-sites of the Niger Delta region of Nigeria. Key Words: Bioremediation, Crude oil polluted-soil, Biostimulation, Bioaugumentation, Poultry droppings, Nitrogen fixing bacteria.


2005 ◽  
Vol 5 (5) ◽  
pp. 906-909 ◽  
Author(s):  
T.A. Adedosu ◽  
O.O. Sonibare .

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