scholarly journals Effect of Aerating Duration on Hydrocarbon Biodegradation in a Simulated Crude-Oil Polluted Aquatic Environment Undergoing Bioremediation

Author(s):  
Ewoh, Prosperity C. ◽  
Peekate, Lekiah P.

The aim of this research work was to determine the aerating duration that would be effective in enhancing hydrocarbon biodegradation rate during bioremediation of crude-oil polluted river. Sediment and river-water were placed in four glass troughs labeled CT (control), A, B, and C. The setups were polluted with crude-oil, and allowed undisturbed for 2 weeks. Subsequently, accessible crude-oil on the surface was removed; bacteria and nutrients were then added. Air was bubbled for 3 hours into setups A, B, and C, at daily, 3 days, and 7 days interval respectively. Aeration was not applied to setup CT. On day 1, 7, 14, and 21, hydrocarbon concentration was determined; populations of total heterotrophic bacteria (THB) and hydrocarbon-utilizing bacteria (HUB) were also determined. The time it will take for hydrocarbons in the setups to biodegraded “completely” was calculated using first-order reaction equation. The results obtained showed that 71.43, 86.39, 83.17, and 15.42 % hydrocarbon degradation were obtained in setup A, B, C, and CT respectively. The time it will take for hydrocarbons in the setups to biodegrade “completely” were 129, 89, 101, and 1079 days for A, B, C, and CT respectively. There was slight reduction in population of HUB in setup CT, fairly stable population in setup A, and increase in population of HUB in setups B and C. It is concluded that aerating crude-oil polluted aquatic environment for 3 hours at 3 days interval will be more effective in enhancing hydrocarbon biodegradation rate during bioremediation.

Author(s):  
Tudararo-Aherobo Laurelta ◽  
Okotie Sylvester ◽  
Ataikiru Tega ◽  
Stephen Avwerosuoghene

Aim: The research aims to assess the biodegradability of crude oil polluted aquatic environment using indigenous hydrocarbon degrading bacteria. Place and Duration of Study: The research was conducted in the Environmental Management and Toxicology Laboratory, Federal University of Petroleum Resources, Effurun, Delta State. Methodology: Hydrocarbon degrading bacteria species were isolated from hydrocarbon contaminated soils, screened and used for the degradation of crude oil. 5% and 10% crude oil were used to spike the test microcosm. Physicochemical parameters such as, pH, turbidity, total petroleum hydrocarbon (TPH) and bacterial counts of the bioremediated crude oil contaminated water were monitored on Day 0, 7 and 14. The biodegradation of the crude oil was done with the various bacteria isolates singly and as a consortium. Standard methods of American Public Health Association (APHA) and American Society for Testing and Materials (ASTM) were used for the analysis. Results: The isolates identified and used for the biodegradation process were, Azomonas sp., Enterococcus sp., Klebsiella sp. and Rhizobactersp. On day 14, in the microcosms with 5% crude oil contamination, Azomonas sp. recorded the highest turbidity reading of 328 ± 2.0 NTU, while Rhizobacter sp. recorded the least with 57.67 ± 0.58 NTU. The bacterial countswere between 7.68 ± 0.002 CFU/ml and 8.05 ± 0.10x 107 CFU/ml for Rhizobacter sp. and Azomonas sp. respectively.The crude oil was also degraded most in the microcosm treated with Azomonas sp. with a residual TPH concentration of 0.0013± 0.005 mg/l.For the 10% crude oil contaminated microcosms, TPH was also biodegraded most by Azomonas sp. with a value of 0.0026 ± 0.002mg/l. Turbidity readings were between 82 ± 1.0 NTU and 375.33 ± 0.57 NTU for Rhizobacter sp. and Azomonas sp. respectively. Bacterial counts were between (7.71± 0.012)x 107CFU/ml – (8.13± 0.001) x 107CFU/ml for Rhizobacter sp. and Azomonassp. respectively. Conclusion:There wasincreased microbial countsand decrease of residual crude oil concentration, indicating degradation of the crude oil by all the isolates.However, Azomonas sp. recorded the highest TPH degradation for both the 5% and 10% crude oil contaminated microcosms.Thus, findings from the research indicate that hydrocarbon degrading bacteria exist in our environment and can be used in the remediation of aquatic polluted environment.


Author(s):  
D. N. Ogbonna ◽  
S. A. Ngah ◽  
R. N. Okparanma ◽  
O. Ule ◽  
R. R. Nrior

Aim: The aim of the study was to assess Percentage Bioremediation of Spent Mushroom Substrate (SMS) and Mucor racemosus in hydrocarbon contaminated soil Place and Duration of Study: A portion of Rivers State University demonstration farmland in Nkpolu-Oroworukwo, Mile 3 Diobu area of Port Harcourt, Rivers State was used for this study. The piece of land is situated at Longitude 4°48’18.50’’N and Latitude 6o58’39.12’’E measuring 5.4864 m x 5.1816 m with a total area of 28.4283 m2. Bioremediation monitoring lasted for 56 days, analysis carried out weekly (per 7 days’ interval). Methodology: Five (5) experimental plots employing the Randomized Block Design were used each having dimensions of 100 x 50 x 30 cm (Length x Breadth x Height) = 150,000cm3. Baseline study of the uncontaminated and the deliberately contaminated agricultural soil was investigated for its microbiota and physico-chemical properties. Two of these plots were designated as pristine (Unpolluted soil) (CTRL 1) and crude oil contaminated soil without nutrient organics and bioaugmenting microbes (CTRL 2); these two serve as controls. Each of the experimental plots, except the control (CTRL 1), was contaminated with 2500 cm3 (2122.25 g) of crude oil giving initial Total Petroleum Hydrocarbon (TPH) value of 8729.00 mg/kg. The crude oil polluted soil in Plot 3 was further treated with 750 ml of Mucor racemosus broth (CS+Muc), Plot 4 was treated with 3000 g of Spent Mushroom Substrate (CS+SMS) while plot 5 was treated with the combination of both (CS+Muc+SMS). The plots were left for 7 days to ensure even distribution and soil-oil bonding. Sampling was done at seven-day interval (Day 1, 7, 14, 21, 28, 35, 42, 49, 56).  Physicochemical parameters monitored were pH, Temperature, Nitrogen, Phosphorus, Potassium, and Total Petroleum Hydrocarbon (TPH) throughout the experimental period. Microbial parameters monitored were Total Heterotrophic Bacteria (THB), Total Heterotrophic Fungi (THF), Hydrocarbon Utilizing Bacteria (HUB) and Hydrocarbon Utilizing Fungi (HUF). Percentage (%) Bioremediation was estimated from percentage (%) reduction of Total Petroleum Hydrocarbon (TPH) from day 1 to day 56 in relation to control plots.  Net % Bioremediation were also assessed to ascertain the actual potential of treatment agents singly or combined. Results: Total Heterotrophic Bacteria (THB) (CFU/g) recorded on day 7 and day 56 of the bioremediation were; day 7; CTRL 1 – US (1.07 x109), CTRL- CS (5.4 x108), CS+Muc (3.0 x108), CS+SMS (4.6 x108) and CS+Muc+SMS (5.0 x108). On day 56, data obtained were CTRL 1 –US (9.4 x108), CTRL 2 –CS (7.2 x109), CS+Muc (3.7 x108), CS+SMS (8.1x108) and CS+Muc+SMS (6.8 x108). The increase in number in the treated plots is a depiction of an increase in activity of the organism and the stimulating effect of bio-organics SMS while the untreated plot CTRL 1-US showed decrease in population at day 56. Similar trend showed for Total Heterotrophic Fungi. Generally, it was observed that the highest growth/ count was recorded at the 7th and 8th week (day 42 or day 49), at the 9th week there was an observable decrease; probably due to depletion of nutrients and other factors such as rainfall and seepage. The Net Percentage Hydrocarbon Utilizing Bacteria and Fungi (Net %HUB and Net %HUF) were highest in Crude Oil contaminated plot treated with Spent Mushroom Substrate (SMS) singly; that is (CS+SMS) (11.02% and 12.07%) and lowest in the uncontaminated soil – Control (CTRL 1 –US) (5.41% and 9.26%) respectively. The trend in decreasing order of Net % Hydrocarbon Utilizing Bacteria were as follows: CS+SMS (11.02%) > CS+Muc+SMS (10.14%) > CS+Muc (9.43%) > CTRL 2 –CS (8.1%) > CTRL 1 –US (5.41%) while Net % Hydrocarbon Utilizing Fungi followed similar trend and were: CS+SMS (12.07%) > CS+Muc+SMS (11.76%) = CS+Muc (11.76%) > CTRL 2 –CS (11.05%) > CTRL 1 –US (9.26%). Evaluation of Amount of Crude Oil or Hydrocarbon remediated and Net %Bioremediation revealed Crude Oil contaminated plot augmented with Mucor racemosus broth singly (CS+Muc) as having the highest bioremediation potential while the least is the untreated soil. The trend is as follows:  CS+Muc (8599.19 mg/kg; 33.93%) > CS+Muc+SMS (8298.95 mg/kg; 32.74%) > CS+SMS (8197.03 mg/kg; 32.34%) > CTRL 2 –CS (166.54 mg/kg; 0.66%) > CTRL 1 –US (85.48 mg/kg; 0.34%) Conclusion: This shows that a single nutrient substrate or augmenting microorganism applied appropriately may have a more positive result, that is; higher bioremediation potential than combined or multiple mixed treatments. It was further observed that microbial counts decreased with time in treatments with augmenting organisms alone but increased considerably in treatments supplement with organics having its peak on the 49th day.   It is therefore recommended that bioremediation of crude oil-polluted soil using bio-augmenting microorganism should be applied appropriately noting the volume: area ratio and be supplemented with efficient nutrient organics after every 49-day interval.


2020 ◽  
Vol 2 (2) ◽  
pp. 12-16
Author(s):  
Obhioze Augustine Akpoka

The capability of indigenous bacteria and microalgae in crude oil effluents to grow in and utilize crude oil as their sole source of carbon and energy provides an environmentally friendly and economical process for dealing with crude oil pollution and its inherent hazards. In view of the toxicity of crude oil spillages to indwellers of the affected ecosystems and the entire affected environment, the isolation of pure bacterial and microalgae cultures from crude effluents is a step in the right direction, particularly for bio-augmentation or bioremediation purposes. The total heterotrophic bacteria count and hydrocarbon utilizing bacteria count, as well as the microalgae count, were determined with the pour plate technique. The physicochemical properties of the effluent samples were also analyzed. Identification of the hydrocarbon utilizing bacteria was performed with phenotypic techniques. The result shows a mean total heterotrophic bacterium count of 5.91 log CFU/ml and a mean microalga count of 4.77 log cells/ml. When crude oil and polycyclic aromatic hydrocarbon (PAH) were used as sole carbon sources, total hydrocarbon utilizing bacteria counts were respectively estimated at 3.89 and 2.89 log CFU/ml. Phenotypic identification of hydrocarbon utilizing bacteria in the crude oil effluents revealed the presence of two main bacterial genera: Streptococcus and Pseudomonas. Data obtained from this study confirmed the biodegradative abilities of indigenous bacterial species, thus, ultimately resulting in the amelioration of the toxicity associated with the crude oil effluents.


Author(s):  
D. N. Ogbonna ◽  
S. I. Douglas ◽  
V. G. Awari

Many substances known to have toxic properties are regularly introduced into the environment through human activity. These substances which include hydrocarbons range in degree of toxicity and danger to human health. Frequent oil spills incidents have become a problem to ecological protection efforts. Conventional methods to remove, reduce or mitigate toxic substances introduced into soil via anthropogenic activities suffer setbacks due to the level of risk involved but bioremediation offers an alternative method to detoxify contaminants especially if the soil conditions are amended with organic nutrients or growth enhancing co-substrates. This study was therefore aimed characterizing hydrocarbon utilizing microorganisms associated with crude oil contaminated soils. Soils were obtained from the Rivers State University Agricultural farm contaminated deliberately with crude oil and allowed for 21 days to mimic the natural polluted soil. Sample collection and analyses were carried out according to standard microbiological procedures while characterization of the isolates was done using genomic studies. The results of microbial counts obtained from the soil samples for total heterotrophic bacteria ranged from 2.10 x108 to 2.58 x108 cfu/g, Total heterotrophic fungi had 1.6 x105 to 2.0 x105 cfu/g while the hydrocarbon utilizing bacteria ranged from 8.0 x103 to 5.0 x104 cfu/g and total hydrocarbon utilizing fungi ranged from 9.0 x103 to 7.0 x104 cfu/g in the contaminated soil. Five hydrocarbon utilizing bacterial species were identified as Staphylococcus saprophyticus, Bacillus amyloliquefaciens, Pseudomonas aeruginosa, Comamonas testosteroni and Chryseobacterium cucumeris while five hydrocarbon utilizing fungal species were identified as Penicillium citrinum, Penicillium brocae, Fusarium solani, Kodamaea ohmeri and Lentinus squarrosulus. Bacillus and Penicillium species were predominantly isolated from the soil. This may be due to the ability of the organisms to produce spores, which may shield them from the toxic effects of the hydrocarbons. Since these organisms are able to utilize crude oil as their sole carbon source. Hence, can be used for bioremediation of crude oil polluted environment.


2014 ◽  
Vol 3 (2) ◽  
pp. 36-47 ◽  
Author(s):  
IA Allamin ◽  
UJJ Ijah ◽  
HY Ismail ◽  
ML Riskuwa

Soil samples were collected from five sites covering petroleum exploration station in Kukawa, Kukawa Local Government Area of Borno State, Nigeria between October, 2012 and February, 2013 at two different depths (0-10cm and 10-20cm) to enumerate and identify hydrocarbon degrading bacteria in the soil. Total aerobic heterotrophic bacteria (TAHB) were enumerated on Nutrient agar (NA), and Hydrocarbon utilizing bacteria (HUB) enumerated on Oil agar (OA). The bacterial isolates were identified using morphological and biochemical tests. It was observed that the microorganisms (TAHB, and HUB) were more densely populated at 10cm depth. (TAHB: 5.3×108 - 11.4×108cfu/g, and HUB: 2.4×105 - 5.3×105 cfu/g, than at 20 cm depth (TAHB: 3.0×108 - 5.7×108 cfu/g, and HUB: 2.1×105 - 4.8×105 cfu/g). The HUB was identified as species of Bacillus, Pseudomonas, Klebsiella, Lactobacillus, Micrococcus, Corynebacterium, and Actinomyces. Bacillus, and Pseudomonas species were more constantly isolated than other isolates and they constitute 100% of total bacterial isolates. The potential of hydrocarbon utilizing bacteria isolated to degrade hydrocarbon was studied. Nineteen (19) bacterial species was screened, Bacillus subtilis, Pseudomonas aeruginosa, Bacillus cereus, Klebsiella pneumoniae, Micrococcus leteus,and Lactobacillus casei, utilized and degrade crude oil at considerably high rates after 21 days of incubation. The degradation efficiency was confirmed by GC-MS analysis, which indicated that the bacterial isolates utilized most of the crude oil components particularly straight chain alkanes and cycloalkanes DOI: http://dx.doi.org/10.3126/ije.v3i2.10503 International Journal of the Environment Vol.3(2) 2014: 36-47


2021 ◽  
Vol 25 (9) ◽  
pp. 1729-1735
Author(s):  
K.I. Ogru ◽  
P.G. Olannye

Soils contaminated with crude oil collected from three sites in Delta State were analyzed using serial dilution and pour plate methods. The physicochemical characteristics of the soil were determined using standard methods. The mean heterotrophic bacteria count and the mean hydrocarbon utilizing bacteria count were also determined. Blood haemolysis, foaming activity, oil spreading techniques and emulsification assay was used to screen the microorganisms for biosurfactant production. The biosurfactant producing bacteria were selected and their effect on metal removal and growth kinetics was also determined. The pH of the contaminated soil samples ranged 4.82 to 5.62. The mineral elements such as potassium (k+) and sodium (Na+) ranged from 0.20 to 0.80 Meq/100g and 0.07 to 0.81 Meq/100g respectively. The heavy metal content such as zinc (Zn2+) and lead (Pb2+) ranged from 10.13 to 19.24 mg/kg and 19.24 to 49.63 mg/kg respectively. Organic carbon and THC ranged from 5.44 to 6.87 % and 2720.00 to 3110.00 mg/kg respectively. The mean heterotrophic bacteria and hydrocarbon utilizing bacteria ranges from 1.4 ± 0.4 x 106 to 1.6 ± 0.7 x 106 and 1.0 ± 0.2 x 106 to 1.2 ± 0.4 × 106 respectively in the soil samples. Bacteria isolated and identified from the three sites include Corynebacterium spp., Bacillus subtilis., Pseudomonas aeruginosa, Micrococcus varians, Streptococcus spp., Klebsiella spp. and Enterobacter spp. with Bacillus subtilis and Pseudomonas aeruginosa having the highest prevalence and among these isolates only Corynebacterium spp., Bacillus subtilis., Pseudomonas aeruginosa and Micrococcus varians showed positive result for the production of biosurfactant. Bacillus subtilis had the highest metal removal capacity of 29.44% of 100 ppm of lead. Corynebacterium spp. and Bacillus subtilis had an optimum growth at pH 8 and 7 respectively while Pseudomonas aeruginosa and Micrococcus varians has an optimum growth at pH.


Fine Focus ◽  
2016 ◽  
Vol 2 (1) ◽  
pp. 7-14
Author(s):  
Chioma Blaise Chikere ◽  
Chinyere Augusta Ajuzieogu ◽  
Michael Chukwugoziem Miller

Hydrocarbon utilizers are expected to be indigenous in crude-oil polluted environments. The isolation and characterization of hydrocarbon utilizers is often a key strategy in bioremediation of hydrocarbon-polluted environments. In this study, crude-oil polluted soil samples from Obagi town, Onelga, Rivers state were enumerated and characterized for putative hydrocarbon utilizing bacterial populations. Biochemical characterization identified five bacterial species representative of five genera: Bacillus, Pseudomonas, Acinetobacter, Micrococcus and Staphylococcus. Amongst the genera of bacteria isolated, Bacillus had the highest frequency of occurrence (40%). The mean count of total heterotrophic bacteria was 1.7 X 107 cfu/g, while hydrocarbon utilizing bacteria (HUB) count mean density was 1.0 X 107 cfu/g for the three soil samples. Statistical analyses revealed no significant difference at p>0.05 between Total Heterotrophic Bacterial (THB) and Hydrocarbon Utilizing Bacterial (HUB) counts, suggesting that most of the bacteria present in the sampled sites were hydrocarbon utilizers. Findings from this study suggest the presence of indigenous putative hydrocarbon utilizing bacteria in the crude-oil polluted soil of Obagi town. Hence, a promising potential exists for future bioremediation studies on the site.


2021 ◽  
Vol 9 (6) ◽  
pp. 1200
Author(s):  
Gareth E. Thomas ◽  
Jan L. Brant ◽  
Pablo Campo ◽  
Dave R. Clark ◽  
Frederic Coulon ◽  
...  

This study evaluated the effects of three commercial dispersants (Finasol OSR 52, Slickgone NS, Superdispersant 25) and three biosurfactants (rhamnolipid, trehalolipid, sophorolipid) in crude-oil seawater microcosms. We analysed the crucial early bacterial response (1 and 3 days). In contrast, most analyses miss this key period and instead focus on later time points after oil and dispersant addition. By focusing on the early stage, we show that dispersants and biosurfactants, which reduce the interfacial surface tension of oil and water, significantly increase the abundance of hydrocarbon-degrading bacteria, and the rate of hydrocarbon biodegradation, within 24 h. A succession of obligate hydrocarbonoclastic bacteria (OHCB), driven by metabolite niche partitioning, is demonstrated. Importantly, this succession has revealed how the OHCB Oleispira, hitherto considered to be a psychrophile, can dominate in the early stages of oil-spill response (1 and 3 days), outcompeting all other OHCB, at the relatively high temperature of 16 °C. Additionally, we demonstrate how some dispersants or biosurfactants can select for specific bacterial genera, especially the biosurfactant rhamnolipid, which appears to provide an advantageous compatibility with Pseudomonas, a genus in which some species synthesize rhamnolipid in the presence of hydrocarbons.


2015 ◽  
Vol 17 (12) ◽  
pp. 2022-2033 ◽  
Author(s):  
Tiantian Shen ◽  
Yongrui Pi ◽  
Mutai Bao ◽  
Nana Xu ◽  
Yiming Li ◽  
...  

The biodegradation rate of crude oil by semi-coke immobilized microbial consortia was higher than that by free microbial consortia.


2013 ◽  
Vol 726-731 ◽  
pp. 2506-2509
Author(s):  
Xiao Xiao Wang ◽  
Xiao Qin Yu ◽  
Jun Ya Pan ◽  
Ji Wu Li

The effects of Pb2+concentration, pH and additional carbon source on biodegradation of 4-chlorophenol (4-CP) byFusariumsp. were investigated, and the characteristic and kinetic of 4-CP biodegradation were analyzed. It was concluded that 4-CP biodegradation rate byFusariumsp. decreased a little at concentration of Pb2+0.20 mg/L and 4-CP 50 mg/L. The suitable biodegradation pH was range from 6 to 7. Additional carbon source (phenol) might increase the rate of 4-CP biodegradation. The kinetic equations of 4-CP biodegradation were well accord with the zero order reaction equation at different concentration of Pb2+.


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