The coastal area is one of the areas that is quite vulnerable to the threat of pollution caused by human activities,including pollution caused by oil spills(hydrocarbons)in the sea.The incident can be caused by severa...The coastal area is one of the areas that is quite vulnerable to the threat of pollution caused by human activities,including pollution caused by oil spills(hydrocarbons)in the sea.The incident can be caused by several factors including the explosion,leakage of petroleum pipelines on the seabed,leakage of tanks or petroleum tankers at sea and disposal of waste petroleum products into the environment.Oil spills continuously can cause environmental contamination and pollution both aquatic and terrestrial.If the petroleum hydrocarbons enter sea waters,some of them will be absorbed by aquatic organisms because the nature of the petroleum hydrocarbons is difficult to decompose in waters.The intentional and unintentional entry of hazardous and toxic substances into marine ecosystems such as petroleum hydrocarbons and chemical solvents resulting from industrial wastes has become a serious problem for human health and the environment.The purpose of this study was to determine the concentration of Total Petroleum Hydrocarbon(TPH)contained in fish in coastal waters of Karawang Regency,West Java Province.This research was conducted in September-November 2019 by taking several fish samples at Ciparage Jaya Fish Auction Place,Betok Mati and Sungai Buntu Rive with a total sample of 24 fish,and taking seawater samples in the three study sites.TPH analysis was carried out at the Integrated Chemistry Laboratory,Bogor Agricultural University.TPH values in fish at Ciparage-1,Ciparage-2,Betok Mati and Sungai Buntu stations,in general,have different mean values but are almost uniform,each at 6.82;6.82;7.45 and 5.12 mg/kg.Based on the average TPH concentration in fish,it can be said that the average TPH in fish at Betok Mati station is relatively higher compared to other stations.TPH values in all fish samples exceed the safe threshold,which is a maximum of 0.002 mg/kg.Based on the results of the Bioaccumulation factor(BAF)analysis showed that the average TPH in fish was 6.55 mg/kg and the average TPH in the waters was 11.23 mg/l,so the BAF value was 58.35 which means that the absorption rate of TPH by fish organisms against the concentration of TPH in the waters of 58.35%.The analysis shows that the value of Ecological Hazard Assessment(EHA)is 3743.33 which means that the level of influence of the hazard on ecosystems and organisms is 3743.33.This value exceeds the recommended threshold according to the European Union,which is a maximum of 0.002 mg/l.展开更多
The remediation of crude oil-impacted soil has always been a challenge in different soil environments and climatic conditions. Bioremediation technology has offered a breakthrough in restoring crude oil-impacted soil/...The remediation of crude oil-impacted soil has always been a challenge in different soil environments and climatic conditions. Bioremediation technology has offered a breakthrough in restoring crude oil-impacted soil/sediment in muddy, dry soil and wetlands. Though, there have been varied environmental conditions that have hampered the success of the bioremediation process. This study has evaluated the effectiveness of a biostimulated bioremediation of crude oil-impacted soil using some design criteria—nutrient amendment (NPK fertilizer) and moisture content. Soil sample sets—A, B, C, D, E, F, and G were impacted with crude oil at a ratio of 10 g/kg and amended with varying amounts of nutrient 30, 60, and 80 g of N.P.K fertilizer. The medium for the inoculation of the nutrient was water and the volume of water applied varied from 30% to 80% saturation. The soil sample sets were harvested at an interval of 3 months for 180 days to determine the concentration of total petroleum hydrocarbon left in the soil. The analysis of the total petroleum hydrocarbon was achieved using a GC-FID with a capillary column and autosampler. Soil samples were extracted with mixed solvent dichloromethane and acetone at a 1:1 ratio. The total petroleum hydrocarbon results show that biostimulated bioremediation achieved better results in soil sample sets with low moisture content (30% water saturation) and moderate nutrient amendment. The biodegradation of the sample sets with high water saturation and a high nutrient amendment was slow with a higher amount of total hydrocarbon content at the end of the 180 days. The variability in the hydrocarbon degradation pattern of contaminated soil shows that biostimulated bioremediation achieved better results in soils with low moisture content than in soil environments with high water content (saturation). More so, nutrient overdosing of the substrate hampered the effectiveness of the remediation process.展开更多
This study was conducted during Dec2011-Nov2012 on three stations located in the south sector of Main Outfall Drain (MOD) River. Station 1 was near Al-Holandee Bridge which was the general carriage way in the center o...This study was conducted during Dec2011-Nov2012 on three stations located in the south sector of Main Outfall Drain (MOD) River. Station 1 was near Al-Holandee Bridge which was the general carriage way in the center of Al-Nassiriya city, station 2 was 20 km far from the first station, while station 3 was in the beginning of the new branch. This study reveals the Seasonal Variation of Total petroleum hydrocarbons (TPHs) in both surface waters, sediment and it is related with trace metals nickel and vanadium in water (dissolved, particulate) and sediment (residual and exchangeable) phases. Also, the study shows the relationships between the concentration of Ni and V with Total Organic Carbon (TOC%) in the sediment.展开更多
The mathematical model of migration of total petroleum hydrocarbons in unsaturated media was described,including convection,molecular diffusion,mechanical dispersion and adsorption,and chemical reactions.By finite ele...The mathematical model of migration of total petroleum hydrocarbons in unsaturated media was described,including convection,molecular diffusion,mechanical dispersion and adsorption,and chemical reactions.By finite element method,a numerical model of evaluating petroleum hydrocarbon migration through contaminated soils was created and applied to the environmental investigations of a relocated mechanical factory in Shanghai.The model consisted of three compacted soil layers:plain fill,sandy silt and silty clay.The results showed that pollutants in the sandy silt traveled faster than that in the plain fill and silty clay.The same decreasing trend of migration velocity was observed in all of the three soil layers.After 180 d,the concentrations of pollutants in the sandy silt can be as low as 40% of the original maximum,while its counterpart in the silty clay is 64%.展开更多
Petroleum products contamination is a world-wide problem that threatens polluting groundwater and surface water systems. However, the problem is not only large-scale in scope when viewed from a case-by-case basis. Man...Petroleum products contamination is a world-wide problem that threatens polluting groundwater and surface water systems. However, the problem is not only large-scale in scope when viewed from a case-by-case basis. Many fueling, construction, agricultural, and industrial activities result in the problem of managing smaller quantities of these soils from an ecological safety perspective. Landfilling has been the disposal method of choice in the US;however, this option is becoming economically prohibitive and it does not really offer a true degradation fate for the pollutants. This study focused on the proving of an innovative biocell design that afforded a high level of petroleum degradation within a simple and cost effective design. Additionally, the design offered a remediation solution for sites not easily accessed. Soil contaminated with both diesel fuel and gasoline collected from a former filling station was used in this on-site remediation case study. Rapid biodegradation of the petroleum products were observed at the initiation of the study with rates leveling off as the study progressed with the final total petroleum hydrocarbon concentration being 10 mg/kg at Day 90. Oxygen uptake rates were monitored and found to nicely track both microbial activity and pollutant removal dynamics. The biocell design met all expectations by being effective, yet simple to build and operate.展开更多
A hydrocarbon degrading bacterial consortium KO5-2 was isolated from oil-contaminated soil of Karamay in Xinjiang, China, which could remove 56.9% of 10 g/L total petroleum hydrocarbons(TPH) at 30 ℃ after 7 days of i...A hydrocarbon degrading bacterial consortium KO5-2 was isolated from oil-contaminated soil of Karamay in Xinjiang, China, which could remove 56.9% of 10 g/L total petroleum hydrocarbons(TPH) at 30 ℃ after 7 days of incubation, and could also remove 100% of fluorene, 98.93% of phenanthrene and 65.73% of pyrene within 3, 7 and 9 days, respectively. Twelve strains from six different genera were isolated from KO5-2 and only eight ones were able to utilize the TPH. The denaturing gradient gel electrophoresis(DGGE) was used to investigate the microbial community shifts in five different carbon sources(including TPH, saturated hydrocarbons, fluorene, phenanthrene and pyrene). The test results indicated that the community compositions of KO5-2 in carbon sources of TPH and saturated hydrocarbons, respectively, were roughly the same, while they were distinctive in the three different carbon sources of PAHs. Rhodococcus sp. and Pseudomonas sp. could survive in the five kinds of carbon sources. Bacillus sp., Sphingomonas sp. and Ochrobactrum sp. likely played key roles in the degradation of saturated hydrocarbons, PAHs and phenanthrene, respectively. This study showed that specific bacterial phylotypes were associated with different contaminants and complex interactions between bacterial species, and the medium conditions influenced the biodegradation capacity of the microbial communities involved in bioremediation processes.展开更多
A computational fluid dynamics(CFD)numerical simulation and field experiment were used to investigate optimal operating parameters of high-pressure jet grouting equipment and clarify the boundary law of the injection ...A computational fluid dynamics(CFD)numerical simulation and field experiment were used to investigate optimal operating parameters of high-pressure jet grouting equipment and clarify the boundary law of the injection area in the remediation process.The response surface optimization design results show that the optimal injection pressure is 30 MPa,rotation speed is 23 r/min,commission speed is 30 cm/min,and the optimal injection diameter is 147.3 cm.Based on the CFD numerical simulation,the ratio of the injection core,turbulent zone,and seepage zone is approximately 1∶4∶2.The distribution law of jet core,turbulence zone and seepage zone at different cross-sections under 30 MPa operating conditions is as follows:The jet core radius is approximately 100 mm,the turbulence zone is mainly distributed at 100 to 500 mm,the seepage zone is mainly distributed at 500 to 700 mm,the seepage zone could be completed within 2 h,and the proportion of the three boundary zones in the injection zone is similar to that of the numerical simulation.This study provides theoretical parameters and practical reference for the remediation of deep pollution via in-situ chemical oxidation in the Loess Plateau soil environment.展开更多
This study was designed and carried out to characterize hydrocarbonoclastic microbial communities in soil polluted with artisanal refined hydrocarbon at Trans Amadi, Phalga Local Government Area of Rivers State, Niger...This study was designed and carried out to characterize hydrocarbonoclastic microbial communities in soil polluted with artisanal refined hydrocarbon at Trans Amadi, Phalga Local Government Area of Rivers State, Nigeria. Heterotrophic bacteria count ranged from 8.0 × 10<sup>5</sup> cfu/gm for sample TSAS1, and 2.1 × 10<sup>6</sup> cfu/gm for sample TSAS2 while TSAS3 was too numerous to count (TNTC). Hydrocarbon utilizing bacteria count ranged from 1.1 × 10<sup>5</sup> cfu/gm for TSAS1, and 5.9 × 10<sup>4</sup> cfu/gm for TSAS2, while TSAS3 was 5.4 × 10<sup>4</sup> cfu/gm. Physiochemical parameters of the soil were determined. The ranges obtained were pH 6.6, conductivity 125 μs/cm, temperature 27.3°C, moisture 7.72, total nitrogen 0.056%, phosphate 1.554 ppm, potassium 145.87 ppm, lead 7.02 ppm, cadmium 0.41 ppm, nickel 1.96 ppm, copper 1.14 ppm, total petroleum hydrocarbon 1487.24181 ppm, polycyclic aromatic hydrocarbon 12.85287 ppm. Isolates of hydrocarbon utilizing bacteria characterized belonged to the genera Escherichia coli, Klebsiella sp., Lactobacillus sp., Enterobacter sp., Serratia sp., and Proteus sp. The findings in this study have revealed the abilities of these groups of bacteria to be employed in bioremediation/biodegradation clean-up practices. Thus the polluted soil may harbour important genera of bacterial species that may have beneficial applications in environmental microbiology for future remediation processes.展开更多
GC-FID methods for the analysis of Petroleum hydrocarbons were developed and optimised. Contamination of soil from the Niger Delta was investigated about 40 days after crude oil spillage from the Shell Petroleum margi...GC-FID methods for the analysis of Petroleum hydrocarbons were developed and optimised. Contamination of soil from the Niger Delta was investigated about 40 days after crude oil spillage from the Shell Petroleum marginal well head. Soil samples and controls were collected at depths of 0 - 15 cm, 15 - 30 cm and 30 - 60 cm. Samples were analysed using gas chromatography fitted with a flame ionisation detector. Penetration and migration of C10-C26 and C26-C34 hydrocarbons through the soil layers were assessed by cluster analysis to determine the spatial distribution, penetration and similarity of these compounds over the contaminated area. The results also indicated elevated levels of total hydrocarbon contents when compared with the reference sites. Recommendations are made to carefully monitor and remediate the environment.展开更多
In the Niger Delta region of Nigeria, oil explorations and exploitations abound, causing environmental pollution with serious consequences on soil ecosystem and its biodiversity. In spite of the relationship between m...In the Niger Delta region of Nigeria, oil explorations and exploitations abound, causing environmental pollution with serious consequences on soil ecosystem and its biodiversity. In spite of the relationship between microbes and fauna in soil ecosystem, such that both organisms can metabolize certain range of petroleum hydrocarbon substrates with the fauna influencing the remediation potentials of bacteria, yet soil fauna is still not fully considered in bioremediation. The influence of earthworm;Lumbricus terrestris on the remediating potentials of soil bacteria in petroleum hydrocarbon contaminated soils was investigated. Eighteen pots were filled with 700 g of soil each, with nine treated with mixture of 3 levels crude oil and remediated with earthworm, while the other nine had no earthworm. The total petroleum hydrocarbon (TPH), soil physical, nutrient compositions, and TPH degrading bacteria biodiversity were determined before contamination or commencement of study and thirty days after. The results showed a decrease in TPH concentration of 55.58%, 62.57% and 67.07% in 1 ml, 2 ml and 3 ml crude oil contaminated soil, respectively. Species richness and abundance of bacteria organisms increased with high relative abundance in soils remediated with earthworms, hydrocarbon utilizing bacteria increased from less than 0.1 cfu/g to 0.4 cfu/g, and total heterotrophic bacteria 1.6 cfu/g at the end of the study. Earthworms increased rate of remediation potentials of bacteria, such that within 30 days post remediation treatment, 34.14% of reduced concentration was achieved over soil samples without earthworms at 3 ml, and 25.14% at 2 ml concentration. Reduction in pH levels in remediated soils was between 6.39 to 6.17 and 6.74 to 6.72 in unremediated soils, while moisture content was 6.73% to 6.77% unremediated and 5.85% to 6.62% in earthworm remediated soils. Total organic carbon, nitrates in soils inoculated with earthworms were lower in concentration than those without earthworms. Reverse was the case with potassium, phosphate and phosphorous concentrations which were above those without earthworms. Results indicate statistically, significant difference between reduction in TPH in earthworm remediated soils and unremediated soils, pointing out that earthworm is a good candidate for facilitation of bacteria remediation-petroleum hydrocarbon contamination.展开更多
文摘The coastal area is one of the areas that is quite vulnerable to the threat of pollution caused by human activities,including pollution caused by oil spills(hydrocarbons)in the sea.The incident can be caused by several factors including the explosion,leakage of petroleum pipelines on the seabed,leakage of tanks or petroleum tankers at sea and disposal of waste petroleum products into the environment.Oil spills continuously can cause environmental contamination and pollution both aquatic and terrestrial.If the petroleum hydrocarbons enter sea waters,some of them will be absorbed by aquatic organisms because the nature of the petroleum hydrocarbons is difficult to decompose in waters.The intentional and unintentional entry of hazardous and toxic substances into marine ecosystems such as petroleum hydrocarbons and chemical solvents resulting from industrial wastes has become a serious problem for human health and the environment.The purpose of this study was to determine the concentration of Total Petroleum Hydrocarbon(TPH)contained in fish in coastal waters of Karawang Regency,West Java Province.This research was conducted in September-November 2019 by taking several fish samples at Ciparage Jaya Fish Auction Place,Betok Mati and Sungai Buntu Rive with a total sample of 24 fish,and taking seawater samples in the three study sites.TPH analysis was carried out at the Integrated Chemistry Laboratory,Bogor Agricultural University.TPH values in fish at Ciparage-1,Ciparage-2,Betok Mati and Sungai Buntu stations,in general,have different mean values but are almost uniform,each at 6.82;6.82;7.45 and 5.12 mg/kg.Based on the average TPH concentration in fish,it can be said that the average TPH in fish at Betok Mati station is relatively higher compared to other stations.TPH values in all fish samples exceed the safe threshold,which is a maximum of 0.002 mg/kg.Based on the results of the Bioaccumulation factor(BAF)analysis showed that the average TPH in fish was 6.55 mg/kg and the average TPH in the waters was 11.23 mg/l,so the BAF value was 58.35 which means that the absorption rate of TPH by fish organisms against the concentration of TPH in the waters of 58.35%.The analysis shows that the value of Ecological Hazard Assessment(EHA)is 3743.33 which means that the level of influence of the hazard on ecosystems and organisms is 3743.33.This value exceeds the recommended threshold according to the European Union,which is a maximum of 0.002 mg/l.
文摘The remediation of crude oil-impacted soil has always been a challenge in different soil environments and climatic conditions. Bioremediation technology has offered a breakthrough in restoring crude oil-impacted soil/sediment in muddy, dry soil and wetlands. Though, there have been varied environmental conditions that have hampered the success of the bioremediation process. This study has evaluated the effectiveness of a biostimulated bioremediation of crude oil-impacted soil using some design criteria—nutrient amendment (NPK fertilizer) and moisture content. Soil sample sets—A, B, C, D, E, F, and G were impacted with crude oil at a ratio of 10 g/kg and amended with varying amounts of nutrient 30, 60, and 80 g of N.P.K fertilizer. The medium for the inoculation of the nutrient was water and the volume of water applied varied from 30% to 80% saturation. The soil sample sets were harvested at an interval of 3 months for 180 days to determine the concentration of total petroleum hydrocarbon left in the soil. The analysis of the total petroleum hydrocarbon was achieved using a GC-FID with a capillary column and autosampler. Soil samples were extracted with mixed solvent dichloromethane and acetone at a 1:1 ratio. The total petroleum hydrocarbon results show that biostimulated bioremediation achieved better results in soil sample sets with low moisture content (30% water saturation) and moderate nutrient amendment. The biodegradation of the sample sets with high water saturation and a high nutrient amendment was slow with a higher amount of total hydrocarbon content at the end of the 180 days. The variability in the hydrocarbon degradation pattern of contaminated soil shows that biostimulated bioremediation achieved better results in soils with low moisture content than in soil environments with high water content (saturation). More so, nutrient overdosing of the substrate hampered the effectiveness of the remediation process.
文摘This study was conducted during Dec2011-Nov2012 on three stations located in the south sector of Main Outfall Drain (MOD) River. Station 1 was near Al-Holandee Bridge which was the general carriage way in the center of Al-Nassiriya city, station 2 was 20 km far from the first station, while station 3 was in the beginning of the new branch. This study reveals the Seasonal Variation of Total petroleum hydrocarbons (TPHs) in both surface waters, sediment and it is related with trace metals nickel and vanadium in water (dissolved, particulate) and sediment (residual and exchangeable) phases. Also, the study shows the relationships between the concentration of Ni and V with Total Organic Carbon (TOC%) in the sediment.
文摘The mathematical model of migration of total petroleum hydrocarbons in unsaturated media was described,including convection,molecular diffusion,mechanical dispersion and adsorption,and chemical reactions.By finite element method,a numerical model of evaluating petroleum hydrocarbon migration through contaminated soils was created and applied to the environmental investigations of a relocated mechanical factory in Shanghai.The model consisted of three compacted soil layers:plain fill,sandy silt and silty clay.The results showed that pollutants in the sandy silt traveled faster than that in the plain fill and silty clay.The same decreasing trend of migration velocity was observed in all of the three soil layers.After 180 d,the concentrations of pollutants in the sandy silt can be as low as 40% of the original maximum,while its counterpart in the silty clay is 64%.
文摘Petroleum products contamination is a world-wide problem that threatens polluting groundwater and surface water systems. However, the problem is not only large-scale in scope when viewed from a case-by-case basis. Many fueling, construction, agricultural, and industrial activities result in the problem of managing smaller quantities of these soils from an ecological safety perspective. Landfilling has been the disposal method of choice in the US;however, this option is becoming economically prohibitive and it does not really offer a true degradation fate for the pollutants. This study focused on the proving of an innovative biocell design that afforded a high level of petroleum degradation within a simple and cost effective design. Additionally, the design offered a remediation solution for sites not easily accessed. Soil contaminated with both diesel fuel and gasoline collected from a former filling station was used in this on-site remediation case study. Rapid biodegradation of the petroleum products were observed at the initiation of the study with rates leveling off as the study progressed with the final total petroleum hydrocarbon concentration being 10 mg/kg at Day 90. Oxygen uptake rates were monitored and found to nicely track both microbial activity and pollutant removal dynamics. The biocell design met all expectations by being effective, yet simple to build and operate.
基金supported by the Scientific Research Fund of Liaoning Provincial Education Department (L2014148)
文摘A hydrocarbon degrading bacterial consortium KO5-2 was isolated from oil-contaminated soil of Karamay in Xinjiang, China, which could remove 56.9% of 10 g/L total petroleum hydrocarbons(TPH) at 30 ℃ after 7 days of incubation, and could also remove 100% of fluorene, 98.93% of phenanthrene and 65.73% of pyrene within 3, 7 and 9 days, respectively. Twelve strains from six different genera were isolated from KO5-2 and only eight ones were able to utilize the TPH. The denaturing gradient gel electrophoresis(DGGE) was used to investigate the microbial community shifts in five different carbon sources(including TPH, saturated hydrocarbons, fluorene, phenanthrene and pyrene). The test results indicated that the community compositions of KO5-2 in carbon sources of TPH and saturated hydrocarbons, respectively, were roughly the same, while they were distinctive in the three different carbon sources of PAHs. Rhodococcus sp. and Pseudomonas sp. could survive in the five kinds of carbon sources. Bacillus sp., Sphingomonas sp. and Ochrobactrum sp. likely played key roles in the degradation of saturated hydrocarbons, PAHs and phenanthrene, respectively. This study showed that specific bacterial phylotypes were associated with different contaminants and complex interactions between bacterial species, and the medium conditions influenced the biodegradation capacity of the microbial communities involved in bioremediation processes.
基金The National Natural Science Foundation of China(No.41967043,52160003)the Natural Science Foundation of Gansu Province(No.20JR5RA461)+1 种基金the Key Project of China Railway Southwest Research Institute Co.,Ltd.(No.2018-KJ003-Z003-XB)the Industrial Support Program of the Higher Education of Gansu Province(No.2020C-40).
文摘A computational fluid dynamics(CFD)numerical simulation and field experiment were used to investigate optimal operating parameters of high-pressure jet grouting equipment and clarify the boundary law of the injection area in the remediation process.The response surface optimization design results show that the optimal injection pressure is 30 MPa,rotation speed is 23 r/min,commission speed is 30 cm/min,and the optimal injection diameter is 147.3 cm.Based on the CFD numerical simulation,the ratio of the injection core,turbulent zone,and seepage zone is approximately 1∶4∶2.The distribution law of jet core,turbulence zone and seepage zone at different cross-sections under 30 MPa operating conditions is as follows:The jet core radius is approximately 100 mm,the turbulence zone is mainly distributed at 100 to 500 mm,the seepage zone is mainly distributed at 500 to 700 mm,the seepage zone could be completed within 2 h,and the proportion of the three boundary zones in the injection zone is similar to that of the numerical simulation.This study provides theoretical parameters and practical reference for the remediation of deep pollution via in-situ chemical oxidation in the Loess Plateau soil environment.
文摘This study was designed and carried out to characterize hydrocarbonoclastic microbial communities in soil polluted with artisanal refined hydrocarbon at Trans Amadi, Phalga Local Government Area of Rivers State, Nigeria. Heterotrophic bacteria count ranged from 8.0 × 10<sup>5</sup> cfu/gm for sample TSAS1, and 2.1 × 10<sup>6</sup> cfu/gm for sample TSAS2 while TSAS3 was too numerous to count (TNTC). Hydrocarbon utilizing bacteria count ranged from 1.1 × 10<sup>5</sup> cfu/gm for TSAS1, and 5.9 × 10<sup>4</sup> cfu/gm for TSAS2, while TSAS3 was 5.4 × 10<sup>4</sup> cfu/gm. Physiochemical parameters of the soil were determined. The ranges obtained were pH 6.6, conductivity 125 μs/cm, temperature 27.3°C, moisture 7.72, total nitrogen 0.056%, phosphate 1.554 ppm, potassium 145.87 ppm, lead 7.02 ppm, cadmium 0.41 ppm, nickel 1.96 ppm, copper 1.14 ppm, total petroleum hydrocarbon 1487.24181 ppm, polycyclic aromatic hydrocarbon 12.85287 ppm. Isolates of hydrocarbon utilizing bacteria characterized belonged to the genera Escherichia coli, Klebsiella sp., Lactobacillus sp., Enterobacter sp., Serratia sp., and Proteus sp. The findings in this study have revealed the abilities of these groups of bacteria to be employed in bioremediation/biodegradation clean-up practices. Thus the polluted soil may harbour important genera of bacterial species that may have beneficial applications in environmental microbiology for future remediation processes.
文摘GC-FID methods for the analysis of Petroleum hydrocarbons were developed and optimised. Contamination of soil from the Niger Delta was investigated about 40 days after crude oil spillage from the Shell Petroleum marginal well head. Soil samples and controls were collected at depths of 0 - 15 cm, 15 - 30 cm and 30 - 60 cm. Samples were analysed using gas chromatography fitted with a flame ionisation detector. Penetration and migration of C10-C26 and C26-C34 hydrocarbons through the soil layers were assessed by cluster analysis to determine the spatial distribution, penetration and similarity of these compounds over the contaminated area. The results also indicated elevated levels of total hydrocarbon contents when compared with the reference sites. Recommendations are made to carefully monitor and remediate the environment.
文摘In the Niger Delta region of Nigeria, oil explorations and exploitations abound, causing environmental pollution with serious consequences on soil ecosystem and its biodiversity. In spite of the relationship between microbes and fauna in soil ecosystem, such that both organisms can metabolize certain range of petroleum hydrocarbon substrates with the fauna influencing the remediation potentials of bacteria, yet soil fauna is still not fully considered in bioremediation. The influence of earthworm;Lumbricus terrestris on the remediating potentials of soil bacteria in petroleum hydrocarbon contaminated soils was investigated. Eighteen pots were filled with 700 g of soil each, with nine treated with mixture of 3 levels crude oil and remediated with earthworm, while the other nine had no earthworm. The total petroleum hydrocarbon (TPH), soil physical, nutrient compositions, and TPH degrading bacteria biodiversity were determined before contamination or commencement of study and thirty days after. The results showed a decrease in TPH concentration of 55.58%, 62.57% and 67.07% in 1 ml, 2 ml and 3 ml crude oil contaminated soil, respectively. Species richness and abundance of bacteria organisms increased with high relative abundance in soils remediated with earthworms, hydrocarbon utilizing bacteria increased from less than 0.1 cfu/g to 0.4 cfu/g, and total heterotrophic bacteria 1.6 cfu/g at the end of the study. Earthworms increased rate of remediation potentials of bacteria, such that within 30 days post remediation treatment, 34.14% of reduced concentration was achieved over soil samples without earthworms at 3 ml, and 25.14% at 2 ml concentration. Reduction in pH levels in remediated soils was between 6.39 to 6.17 and 6.74 to 6.72 in unremediated soils, while moisture content was 6.73% to 6.77% unremediated and 5.85% to 6.62% in earthworm remediated soils. Total organic carbon, nitrates in soils inoculated with earthworms were lower in concentration than those without earthworms. Reverse was the case with potassium, phosphate and phosphorous concentrations which were above those without earthworms. Results indicate statistically, significant difference between reduction in TPH in earthworm remediated soils and unremediated soils, pointing out that earthworm is a good candidate for facilitation of bacteria remediation-petroleum hydrocarbon contamination.
