Showing papers on "Total petroleum hydrocarbon published in 2005"

Bacterial community dynamics and polycyclic aromatic hydrocarbon degradation during bioremediation of heavily creosote-contaminated soil.

Abstract: Bacterial community dynamics and biodegradation processes were examined in a highly creosote-contaminated soil undergoing a range of laboratory-based bioremediation treatments. The dynamics of the eubacterial community, the number of heterotrophs and polycyclic aromatic hydrocarbon (PAH) degraders, and the total petroleum hydrocarbon (TPH) and PAH concentrations were monitored during the bioremediation process. TPH and PAHs were significantly degraded in all treatments (72 to 79% and 83 to 87%, respectively), and the biodegradation values were higher when nutrients were not added, especially for benzo(a)anthracene and chrysene. The moisture content and aeration were determined to be the key factors associated with PAH bioremediation. Neither biosurfactant addition, bioaugmentation, nor ferric octate addition led to differences in PAH or TPH biodegradation compared to biodegradation with nutrient treatment. All treatments resulted in a high first-order degradation rate during the first 45 days, which was markedly reduced after 90 days. A sharp increase in the size of the heterotrophic and PAH-degrading microbial populations was observed, which coincided with the highest rates of TPH and PAH biodegradation. At the end of the incubation period, PAH degraders were more prevalent in samples to which nutrients had not been added. Denaturing gradient gel electrophoresis analysis and principal-component analysis confirmed that there was a remarkable shift in the composition of the bacterial community due to both the biodegradation process and the addition of nutrients. At early stages of biodegradation, the α-Proteobacteria group (genera Sphingomonas and Azospirillum) was the dominant group in all treatments. At later stages, the γ-Proteobacteria group (genus Xanthomonas), the α-Proteobacteria group (genus Sphingomonas), and the Cytophaga-Flexibacter-Bacteroides group (Bacteroidetes) were the dominant groups in the nonnutrient treatment, while the γ-Proteobacteria group (genus Xathomonas), the β-Proteobacteria group (genera Alcaligenes and Achromobacter), and the α-Proteobacteria group (genus Sphingomonas) were the dominant groups in the nutrient treatment. This study shows that specific bacterial phylotypes are associated both with different phases of PAH degradation and with nutrient addition in a preadapted PAH-contaminated soil. Our findings also suggest that there are complex interactions between bacterial species and medium conditions that influence the biodegradation capacity of the microbial communities involved in bioremediation processes.

Effect of petroleum-containing wastewater irrigation on bacterial diversities and enzymatic activities in a paddy soil irrigation area

Abstract: Effects of petroleum contamination on bacterial diversities and enzymatic activities in paddy soils were investigated in the Shenfu irrigation area, the largest area irrigated by oil-containing wastewater for more than 50 yr in northeastern China. Bacterial diversities were determined by conventional colony morphology typing techniques and 16S rDNA polymerase chain reaction (PCR)-denaturing gradient gel electrophoresis (DGGE). Dehydrogenase, hydrogen peroxidase, polyphenol oxidase, urease, and substrate-induced respiration (SIR) were measured to evaluate the effects of petroleum-containing wastewater irrigation on soil biochemical characteristics. Results showed that paddy soil total petroleum hydrocarbon (TPH) concentration in the irrigation area varied from 277.11 to 5213.37 mg kg(-1) dry soil. Soil TPH concentration declined along the gradient of the irrigation channel from up- to downstream. At the current pollution level, the paddy soil TPH concentration was positively correlated with the colony forming units (CFU) of aerobic heterotrophic bacteria (AHB) (r = 0.928, p < 0.001) and the genetic diversity based on DGGE profiles (r = 0.655, p < 0.05). The bacterial diversities in the soils based on colony morphotypes of AHB also increased with TPH concentration (r = 0.598), but not significant statistically (p = 0.052). Analysis of soil enzyme activities indicated a significant positive correlation between soil TPH concentration and activities of dehydrogenases (r = 0.974, p < 0.001), hydrogen peroxidases (r = 0.957, p < 0.001), polyphenol oxidases (r = 0.886, p < 0.001), and SIR (r = 0.916, p < 0.001). On the contrary, the urease activity showed a negative correlation with paddy soil TPH concentration (r = -0.814, p = 0.002), and could be used as a sensitive indicator of petroleum contamination.

Bioremediation of oil-polluted soil by Lentinus subnudus , a Nigerian white-rot fungus

Abstract: Inspite of the realization and studies on the use of microorganisms in degrading hydrocarbons there has been very little work on indigenous white-rot fungi in Nigeria, a leading oil – producing country. the ability of Lentinus subnudus to mineralize soil contaminated with various concentrations of crude oil was tested. Organic matter and carbon were higher than the control at all concentrations of crude oil contamination in soils inoculated with L. subnudus for 3 months. Nutrient contents were generally higher after 6 months of incubations except potassium levels which were not significantly different from the control. As for the total petroleum hydrocarbon (tph) in crude – oil contaminated soils; the highest rate of biodegradation was at 20% concentration after 3 months and 40% after 6 months of incubation. Key words : bioremediation, crude oil, total petroleum hydrocarbon oil-polluted soil, Lentinus subnudus African Journal of Biotechnology Vol. 4 (8), pp. 796-798

Remediation of crude oil contaminated soil by enhanced natural attenuation technique

Abstract: The concentrations of nitrogen, phosphorus, total hydrocarbon utilizing bacteria (THUB), total heterotrophic bacteria (THB) and total petroleum hydrocarbon were determined using the remediation by enhanced natural attenuation (RENA) in a crude oil contaminated farmland in Rivers state, Nigeria. A TPH concentration of 1.1004 x10 4 mg/kg of the sandy soil was achieved after spiking and tilling. There was a reduction in the TPH level from 300mg/kg after 8 weeks, to 282mg/kg after 10 weeks. No significant reduction in the TPH level was observed after the 10 th week. The nitrogen and phosphorus levels of the sandy soil were 24.6 and 22.8mg/kg respectively. This suggests that the nitrogen and phosphorus levels could no longer support biodegradation at the residual TPH levels of 282mg/kg and 22.8mg/kg after spiking and tilling respectively, which further reduced to 0.12mg/kg and 1.7mg/kg respectively after 10 weeks. The total hydrocarbon utilizing bacteria (THUB) increased from 3.0 x 10 4 cfu/g to 8.55x10 4 cfu/g and finally reduced to 5.38 x10 4 cfu/g, while the total heterotrophic bacteria (THB) reduced from 1.22 x10 8 cfu/g to 5.98 x 10 5 cfu/g. Data of the study indicate that remediation enhanced natural attenuation technique could be employed to remediate a farm settlement contaminated by crude oil. Journal of Applied Sciences and Environmental Management Vol. 9(1) 2005: 103-106

Kinetic Evaluation of a Field-Scale Activated Sludge System for Removing Petroleum Hydrocarbons from Oilfield-Produced Water

Abstract: Produced water is the single largest volume of wastewater generated by the oil and gas industry. Toxic petroleum hydrocarbons found in oilfield-produced waters have increasingly become the major environmental problem facing the U.S. and world oil and gas industry. Uncontrolled releases to the environment using outdated and inefficient technological control systems and methods have continually put surface and ground water environments at risk. In turn, this has placed the oil and gas industries with increasing environmental regulatory compliance costs. With the decline in oil and natural gas prices and the introduction of more stringent produced water surface discharge permit actions, many of these wells are nearing their economic limit. These low-volume marginal wells are being plugged and abandoned because the production, maintenance, treatment, and disposal costs are higher than the selling price. Therefore, in an effort to keep many of our nation's mature oil and gas fields productive, alternative technologies must be evaluated. This research project provided a comprehensive treatment of produced waters using an activated sludge system. The kinetic coefficients determined resulted in a total petroleum hydrocarbon removal efficiency of 99% at a produced water flow rate of 1890 L/day, and a mean cell residence time of 20 days. Kinetic coefficients were determined to be 0.69 (mg/MLSS)/mg total n-alkanes (TNA) and 0.01, 0.44, 2.00, and 0.27 day−1 for Y, kd, k, Ks, and μmax, respectively. © American Institute of Chemical Engineers Environ Prog, 2004

Effects of long‐chain hydrocarbon‐polluted sediment on freshwater macroinvertebrates

Abstract: High-molecular weight (> C16) hydrocarbons (HMWHs) are common pollutants in sediments of freshwater systems, particularly urban water bodies. No sediment quality guidelines exist for total hydrocarbons; more emphasis is placed on polyaromatic hydrocarbons, the most toxic component of hydrocarbons. A field-based microcosm experiment was conducted to determine whether unpolluted sediments spiked with synthetic motor oil impair freshwater macroinvertebrate assemblages. Total petroleum hydrocarbon (TPH) concentrations of 860 mg/kg dry weight significantly increased the abundance of Polypedilum vespertinus and Cricotopus albitarsis and decreased the abundance of Paratanytarsus grimmii adults (all Chironomidae), whereas TPH concentrations ranging from 1,858 to 14,266 mg/kg produced a significant reduction in the total numbers of taxa and abundance, with significant declines in the abundance of nine chironomid taxa. About 28% of water bodies surveyed in urban Melbourne, Australia, had TPH concentrations in sediments likely to cause ecological impairment, and about 14% of the water bodies surveyed are likely to have reduced species richness and abundance. Therefore, HMWHs can be a significant pollutant in urban water bodies. Freshwater sediment quality guidelines should be developed for this ubiquitous urban pollutant.

Assessment of organic pollutants in the offshore sediments of Dubai, United Arab Emirates

Abstract: Fifteen stations (st) were selected along Dubai coastal region to delineate the distribution and the source of total petroleum hydrocarbon (TPH), total organic carbon (TOC), total Kjeldhal nitrogen (TKN), polycyclic aromatic hydrocarbon (PAHs) and polychlorinated biphenyls. The concentrations of TPH fluctuated between 2 μg g −1 and 48018 μg g −1 and the values of TOC were in the range of 0.16–5.9 wt%, while TPAHs ranged from 0.09 μg g −1 to 161.72 μg g −1. On the other hand, TPCBs showed values between 0.8 μg kg−1 and 93.3 μg kg−1 and TKN values varied from 218 μg g−1 to 2457 μg g −1. Distribution of oil and organic compounds in Dubai sediments are safe compared with previous studies except for limited areas at the northeastern offshore. These readings are probably due to: (1) presence of commercial or industrial ports, dry docks and fishing harbours and (2) population centers mainly concentrated at the northern part of the study area. Results indicate that TOC can be used as indicator of oil pollution only in heavily oiled sediments. The highest values of TOC, TPH, TPAHs and TPCBs corresponded to the stations covered with fine sand, due to adsorption properties and larger surface area. The evaporation of low boiling point compounds from surface layers led to enrichment of sediments with the thick residual. Al-Hamriya St 3 exhibited the highest values of TPH, TOC, TPAHs and TPCBs and the second highest value of TKN.

Remediation of a spill of crude oil and brine without gypsum

Abstract: The empowerment of small independent oil and gas producers to solve their own remediation problems will result in greater environmental compliance and more effective protection of the environment, as well as making small producers more self-reliant. Here, we report on the effectiveness of a low-cost method of remediation of a combined spill of crude oil and brine in the Tallgrass Prairie Preserve in Osage County, Oklahoma. Specifically, we have used hay and fertilizer as amendments for remediation of both the oil and the brine. No gypsum was used. Three spills of crude oil plus produced water brine were treated with combinations of ripping, fertilizers and hay, and a downslope interception trench in an effort to demonstrate an inexpensive, easily implemented, and effective remediation plan. No statistically significant effect of treatment on the biodegradation of crude oil was, however observed. Total petroleum hydrocarbon (TPH) reduction clearly proceeded in the presence of brine contamination. The average TPH half-life considering all impacted sites was 267 days. The combination of hay addition, ripping, and a downslope interception trench was superior to hay addition with ripping or ripping plus an interception trench in terms of rates of sodium and chloride leaching from the impacted sites. Reductions in salt inventories (36 months) were 73% in the site with hay addition, ripping, and an interception trench, 40% in the site with hay addition and ripping only, and less than 3% in the site with ripping and an interception trench.

Biological Treatment of Petroleum in Radiologically Contaminated Soil

Abstract: This chapter describes ex situ bioremediation of the petroleum portion of radiologically co-contaminated soils using microorganisms isolated from a waste site and innovative bioreactor technology. Microorganisms first isolated and screened in the laboratory for bioremediation of petroleum were eventually used to treat soils in a bioreactor. The bioreactor treated soils contaminated with over 20,000 mg/kg total petroleum hydrocarbon and reduced the levels to less than 100 mg/kg in 22 months. After treatment, the soils were permanently disposed as low-level radiological waste. The petroleum and radiologically contaminated soil (PRCS) bioreactor operated using bioventing to control the supply of oxygen (air) to the soil being treated. The system treated 3.67 tons of PCRS amended with weathered compost, ammonium nitrate, fertilizer, and water. In addition, a consortium of microbes (patent pending) isolated at the Savannah River National Laboratory from a petroleum-contaminated site was added to the PRCS system. During operation, degradation of petroleum waste was accounted for through monitoring of carbon dioxide levels in the system effluent. The project demonstrated that co-contaminated soils could be successfully treated through bioventing and bioaugmentation to remove petroleum contamination to levels below 100 mg/kg while protecting workers and the environment from radiological contamination.

Monitoring of bioventing process for diesel-contaminated soil by dehydrogenase activity, microbial counts and the ratio ofn-alkane/isoprenoid

Abstract: Monitoring parameters were evaluated for a bioventing process that was designed to treat soils contaminated with diesel fuel. Statistical analyses were conducted to evaluate correlations between total petroleum hydrocarbon concentrations in the contaminated soil and physico-chemical parameters of soil such as microbial counts, dehydrogenase activity, andn-alkane/isoprenoid ratio. The correlation coefficients (r2) obtained showed that TPH concentrations in the bioventing system were strongly correlated with dehydrogenase activity (DHA), total heterotrophic bacterial count, and hydrocarbon utilizing bacterial count. Thus, it was concluded that these parameters could useful monitoring parameters for soils contaminated with diesel fuel

Feasibility study of bioremediation of a drilling-waste-polluted soil: stimulation of microbial activities and hydrocarbon removal.

Abstract: The objective of this study was to determine the feasibility of bioremediation as a treatment option for an aged and chronically polluted drilling waste soil located at the Southeast of Mexico. The polluted drilling-waste site with a mean total petroleum hydrocarbon concentration (TPHs) of 39,397 ± 858 mg/kg was treated with one dose of a nutrient-surfactant commercial product at 40 mg/kg soil and two doses of H2O2 (50 and 100 mg H2O2/kg soil). In this study, the parameters that were monitored include soil respiration, heterotrophic and hydrocarbon-degrading bacteria as biological indicators, catalase and dehydrogenase activities, and TPHs degradation as decontamination parameters. The results demonstrated that the microbial activities can be stimulated in a polluted drilling-waste site by the addition of H2O2 and commercial product, thereby resulting in increasing TPHs degradation. These aspects must be taken into account when biodegradation studies involve the application of a commercial product.

Bioremediation of oil-polluted soil by Lentinus subnudus, a Nigerian white-rot fungus

Abstract: Inspite of the realization and studies on the use of microorganisms in degrading hydrocarbons there has been very little work on indigenous white-rot fungi inNigeria, a leading oil – producing country. the ability of Lentinus subnudus to mineralize soil contaminated with various concentrations of crude oil was tested. Organic matter and carbon were higher than the control at all concentrations of crude oil contamination in soils inoculated with L. subnudus for 3 months. Nutrient contents were generally higher after 6 months of incubations except potassium levels which were not significantly different from the control. AS for the total petroleum hydrocarbon (tph) in crude – oil contaminated soils; the highest rate of biodegradation was at 20% concentration after 3 months and 40% after 6 months of incubation. Key words: Bioremediation, crude oil, total petroleum hydrocarbon oil-polluted soil,Lentinus subnudus.

[Impacts of petroleum-containing wastewater irrigation on microbial population and enzyme activities in paddy soil of Shenfu irrigation area].

Abstract: The study showed that the upper reaches of main petroleum-containing wastewater irrigation channels had the highest accumulation and distribution of total petroleum hydrocarbon (TPH) (5 213.37 mg x kg(-1) dry soil),and the CFU of soil bacteria and fungi was increased with increasing soil TPH concentration, the correlation coefficient being 0.928 (P < 0.001) and 0.772 (P < 0.05), respectively. The activities of soil dehydrogenase, catalase and polyphenoloxidase had a significantly positive correlation with soil TPH concentration, their correlation coefficient being 0.974 (P < 0.001), 0.957 (P < 0.001) and 0.886 (P < 0.001), respectively, while soil urease activity showed a significantly negative correlation (P = 0.002), which could be used as the most sensitive indicator of petroleum contamination. The substrate-induced respiration (SIR) of polluted soil was significantly correlated with soil TPH concentration (P < 0.001), dehydrogenase activity (P < 0.001), and heterotrophic bacterial CFU (P = 0.006).

Mycoremediation of Engine-Oil-Polluted Soil by Lentinus squarrosulus Mont., an Indigenous Nigerian White-Rot Fungus

Abstract: Th ere has been an increasing interest in the use of mushrooms in bioremediation of polluted habitats because of their ability to change the nutrient conditions in the soil and to accumulate metal ions, including heavy metals. Despite the upsurge in the research activities elsewhere, these studies are still in their infancy in Nigeria, which is one of the world’s leading oil producers. Lentinus squarrosulus Mont., a white-rot fungus, was tested for its ability to bioremediate a soil contaminated with 0.5–40% concentrations of engine oil over a period of 3 months. Results obtained revealed that in soils contaminated with engine oil and inoculated by L. squarrosulus, the amount of organic matter, carbon, nitrogen, and phosphorus increased, whereas the available potassium was reduced. A relatively high percentage degradation of total petroleum hydrocarbon (TPH) was observed in low concentrations of engine oil and a considerably lower percentage for the higher concentrations of engine oil. Th e metal concentration of Fe, Cu, Zn, and Ni increased with the increase of engine oil concentration up to 20%, followed by a decrease showing bio-accumulation by the white-rot fungus. Th e improvement of nutrient content values as well as the bioaccumulation of heavy metals at 20% engine oil concentration by L. squarrosulus is of importance for the mycoremediation of an engine-oil polluted soil.

Weathering Effects on Biodegradation and Toxicity of Hydrocarbons in Groundwater

Abstract: This study examined the effect of weathering on hydrocarbon biodegra- dation and toxicity at a former oil field near Guadalupe, California. Soil and groundwater at this site contains residual diesel-range hydrocarbons formerly used to dilute the viscous crude oil to facilitate pumping (Lundegard and Garcia, 2001). Natural attenuation is being considered at this site as a means of remediating residual hydrocarbons in soil and groundwater. To provide the lines of evidence required for use of natural attenuation at this site, this research was undertaken to determine if the hydrocarbons continue to be biodegradable after extensive weathering in the field. Observed hydrocarbon biodegra- dation rates were directly proportional to initial total petroleum hydrocarbon (TPH) con- centration, suggesting first-order kinetics. Highly weathered hydrocarbons most distant downgradient from the source zones exhibited slightly lower biodegradation rate con- stants. Microtox ® toxicity decreased rapidly during 20 days of biodegradation in labora-

Pollutant Removal Capacity of Stormwater Catchbasin Inserts

Abstract: Transportation facilities such as parking lots or maintenance yards often do not have provisions to treat stormwater prior to discharge. Catchbasin inserts can provide a retrofit alternative as a method to meet the new National Pollution Discharge Elimination System Phase II stormwater pollution prevention regulations. Six inserts manufactured by five manufacturers were evaluated for removal of suspended solids, petroleum hydrocarbons, and zinc using a pilot scale catchbasin and a simulated stormwater. At a flowrate of 0.011 to 0.013 m 3 /s (180 to 200 gpm) and pollutant concentrations of 225 to 260 mg/L suspended solids and 30 to 42 mg/L total petroleum hydrocarbon, the inserts were capable of removing 11 to 42 percent of suspended solids and 0 to 40 percent of total petroleum hydrocarbons.

Comprehensive GC (GC×GC) as a Tool for Assessment of Remediation Potential of Oil Contaminated Soils

Abstract: This report presents the evaluation of two-dimensional gas chromatography (GC×GC) as a novel analytical tool for assessment of oil contaminated soils. The thesis project was carried out at VITO, Belgium and the results will be used in a soil remediation project by a petroleum company. In previous oil polluted soil remediation projects, conventional GC-FID was normally used for characterisation of pollutants in soil samples. Different methods such as the TPH (total petroleum hydrocarbon) methods were developed for GC-FID. The results obtained from GC-FID are usually not sufficient to be used by environmental scientists for soil remediation projects. As a new analytical technique, GC×GC has been proved more powerful than conventional GC, especially for analysis of complex environmental samples. Several series of experiments were carried out in order to find the optimal operating conditions. Three columns with different stationary phase (BP20, SolGelwax and BPX50) were tested as second dimension column. BPX50 was chosen as the preferred column because the other two were not stable at high temperature. The goal of the optimisation was to maximize the plate number in second dimension, and at the same time avoid the wrap-around and breakthrough problems. A compromise had to be made between analysis time, separation power and wrap-around of high boiling point compounds in second dimension to obtain the optimal condition. In order to investigate the water solubility and volatility characteristics for pollutants in soil samples, several boiling point/LogKow matrices were built for both specific petroleum hydrocarbons and compounds in different organic groups. A good correlation between LogKow values and retention time coordinates in the boiling point/LowKow matrix was obtained for petroleum hydrocarbons. However, the same regularity could not be applied to compounds in different organic groups. BPX50 showed a comparable result compared to SolGelwax for petroleum hydrocarbons. A six week biodegradation study for oil contaminated soil samples was also carried out in this project. Original extracts of the selected soil sample and the extracts after 2 weeks, 4 weeks and 6 weeks biodegradation were analysed by GC×GC. As a comparison, three window defining methods were developed to show biodegradation information. GC×GC gave more detailed information compared to conventional GC for biodegradation studies. GC×GC also gave the possibility to make a distinction between major chemical classes of (poly)aromatic hydrocarbons. The methods developed for GC×GC are faster, easier and more suitable for analysis of a large number of soil samples.

Provisional Reference Dose for the Aromatic Fraction of Jet Fuel: Insight into Complex Mixtures

Abstract: : Previous efforts to define toxicity criteria for human health risk assessment of complex petroleum mixtures use health effects information for only a subset of the chemicals in such mixtures. The Total Petroleum Hydrocarbon Criteria Working Group (TPHCWG) developed a practical alternative by defining all petroleum mixtures as thirteen carbon number range fractions based on expected transport characteristics following release to the environment. The TPHCWG developed toxicity criteria for each fraction using all available data, prioritizing mixture toxicity information. However, limited toxicity data were available to represent the fractions, including the EC>8 - EC16 aromatic fraction, which is believed to be one of the more toxic fractions. To address this data gap, a 90-day oral gavage toxicity study was conducted in female Sprague-Dawley rats and male CS7BL/6 mice to characterize toxic effects of the EC>8 - EC16 aromatic fraction of Jet Fuel A. Animals were dosed at 0, 20, 100 and 500 mg/kg/day.

Application of oily sludge-treatment with excellent strains by composting

Abstract: A phosphate and a nitrate source were provided,the composting of oily sludge in refinery with the designated mixture of four excellent strains in 120 days at the averaged temperature of-3.9 ℃ resulted in TPH(total petroleum hydrocarbon) less than 3 000 μg/g dry sludge,which has met GB4284-84.And the mass fraction of sulfide reduces from 28 μg/g to 4 μg/g.The biodegradation of each chemical component was analyzed to probe the rule by the GC-MS.The result demonstrates the importance of utilizing foreign microbes which adapted to the pollutants to enhance the efficiency and productivity of bioremediation process.