Crude Oil Contamination Research Articles

Applications of functional nanoparticle–stabilized surfactant foam in petroleum-contaminated soil remediation

Surfactant foam (SF) can be used to remediate petroleum-contaminated soil because of its easy transfer to inhomogeneous and low-permeability formations. Nanoparticles (NPs) not only stabilize SF under extreme conditions but also impart various functions, aiding the removal of petroleum contaminants. This review discusses the stabilization mechanisms of nanoparticle-stabilized SF (NP-SF) as well as the effects of NP size, chargeability, wettability, and NP-to-surfactant ratio on foam stability. SF stabilized by inert SiO2 NPs is most commonly used to remediate soil contaminated with crude oil and diesel. Low dose of SF stabilized by nano zero-valent iron is cost-effective for treating soil contaminated with chlorinated organics and heavy metal ions. The efficiency and recyclability of Al2O3/Fe3O4 NPs in the remediation of diesel and crude oil contamination could be enhanced by applying a magnetic field. This review provides a theoretical basis and practical guidelines for developing functional NP-SF to improve the remediation of petroleum-contaminated soils. Future research should focus on the structural design of photocatalytic NPs and the application of catalytic NP-SF in soil remediation.

Alterations in energy metabolism, total protein, uric and nucleic acids in African sharptooth catfish (Clarias gariepinus Burchell) exposed to crude oil and fractions

Water contamination by crude oil is a growing challenge and little is known about the probabilistic and non-probabilistic ecosystem and species consequences. Therefore, research aimed at understanding species survival strategy in crude oil-contaminated environments with focus on cellular metabolic alterations and dynamics is vital. This study assessed the alterations in lactate dehydrogenase (LDH), glucose (GLU), glucose-6-phosphate dehydrogenase (G-6-PDH), total protein (TP), uric and nucleic acids (UA, RNA, and DNA) in the liver, heart, kidney, blood supernatants, and muscle homogenates of African sharptooth catfish ([ASC] Clarias gariepinus) exposed to varying bonny-light crude oil concentrations to understand the underlying cause of their delayed development as well as potential health and wellbeing. Three concentrations (20, 50, and 100 mg/L) of diluted whole bonny-light crude oil (DWC), water-soluble (WSF), and water-insoluble (WIF) fractions of bonny-light crude oil were used to grow ASC for 9 weeks at room temperature. Biochemical assessments revealed significant (at p < 0.05) elevations in heart LDH (48.57 ± 4.67 to 3011.34 ± 4.67 U/L) and blood G-6-PDH activities (54.86 ± 0.00 to 128 ± 18.29 mU/mL), GLU (0.22 ± 0.01 to 0.77 ± 0.01 mg/dL), TP (5.15 ± 0.14 to 22.33 ± 0.21 g/L), UA (0.29 ± 0.05 to 10.05 ± 0.27 mg/dL), as well as liver DNA (0.38 ± 0.02 to 2.33 ± 0.09 μg/mL) and RNA (12.52 ± 0.05 to 30.44 ± 0.02 μg/mL) levels for laboratory-grown ASC in DWC, WSF, WIF, and oil-impacted Ubeji river collected ASC relative to the control. Due to greater levels of cellular metabolic alterations in oil-impacted Ubeji River collected ASC, it is evident that bonny-light contamination levels in the river is greater than 100 mg/L. In conclusion, bonny-light crude oil is toxic to ASC and induces stress response. The ecological changes caused by bonny-light crude oil contamination may ultimately affect niche functioning and the development of organs in ASC.

Evaluation of the Impact of Crude Oil Contamination on Soil's Physicochemical Characteristics, Micro-flora and Crop Yield

The effects of crude oil pollution on soil physicochemical properties, microflora, and ecotoxicity were evaluated. Soil samples were contaminated with crude oil, and the effects of contamination on the physicochemical parameters, microflora, and growth index of bean (Phaseolus vulgaris) seeds were studied over a 6-month period. The heterotrophic bacteria isolated from the uncontaminated soil were Micrococcus, Klebsiella, Flavobacterium, Bacillus, Pseudomonas, and Serratia species, and the moulds included microbes such as Aspergillus niger, Fusarium, and Mucor sp. Petroleum contamination increased the pH of the soils to alkaline values while increasing the total nitrogen, organic carbon, and phosphorus contents. Electrical conductivity, nitrogen content, and phosphorus content were significantly reduced after petroleum contamination (p ˂ 0.05). The heavy metal contents of the contaminated soils decreased with increasing remediation time. Zinc, total nitrogen, total organic carbon, and electrical conductivity contents were statistically significantly different among samples throughout the bioremediation period (p ˂ 0.05). The ability of isolates to utilise hydrocarbons was highest for Pseudomonas and Bacillus species and lowest for Klebsiella and Serratia species. After a germination period of 12 days, a germination test showed that the bioattenuated polluted soil improved germination of bean seeds. Bioattenuation methods should be used and improved as a means of remediating petroleum-polluted sites because they are cost-effective and environmentally friendly.

Functional response of microbial communities in lab-controlled oil-contaminated marine sediment.

Crude oil contamination is one of the biggest problems in modern society. As oil enters into contact with the environment, especially if the point of contact is a body of water, it begins a weathering process by mixing and spreading. This is dangerous to local living organisms' communities and can impact diversity. However, despite unfavorable conditions, some microorganisms in these environments can survive using hydrocarbons as a nutrient source. Thus, understanding the local community dynamics of contaminated areas is essential. In this work, we analyzed the 16S rRNA amplicon sequencing and metatranscriptomic data of uncontaminated versus contaminated shallow marine sediment from publicly available datasets. We investigated the local population's taxonomic composition, species diversity, and fluctuations over time. Co-expression analysis coupled with functional enrichment showed us a prevalence of hydrocarbon-degrading functionality while keeping a distinct transcriptional profile between the late stages of oil contamination and the uncontaminated control. Processes related to the degradation of aromatic compounds and the metabolism of propanoate and butanoate were coupled with evidence of enhanced activity such as flagellar assembly and two-component system. Many enzymes of the anaerobic toluene degradation pathways were also enriched in our results. Furthermore, our diversity and taxonomical analyses showed a prevalence of the class Desulfobacteria, indicating interesting targets for bioremediation applications on marine sediment.

Use of an Eletrokinetic Remediated Soil as a Road Subgrade Material

The soil investigated for suitability checks, as a subgrade material in this study, was a crude oil contaminated (COC) soil treated using an electrokinetic technique. The index properties and compaction characteristics of the electrokinetic remediated (EKR) soil are natural moisture content was 10.97%; The Atterberg limit test showed liquid limit, plastic limit, plasticity index and linear shrinkage of 36.50%, 22.05%,14.45 %, and 4.30%, respectively. The percentage of 62.80% passes 0.075mm sieve with a maximum dry density (MDD) of 1.77 Mg/m3, and the moisture content decreased from 13.2% to 11.81%. The soil is classified as A-6 according to AASHTO classification system and belong to clay of low plasticity CL or OL group according to the Unified Soil Classification System. The unconfined compression strength, (UCS), durability, and California bearing ratio (CBR) of the electrokinetic remediated soil improved marginally from 46.63kN/m2 to 92.64kN/m2; from 18% to 23%; and from 2.55% to 4.05% respectively. However, these results obtained, do not meet the minimum requirement of the Nigerian General Specification. As a result, it is advised for further research, that an EKR soil be stabilized using cement stabilization to achieve the desired subgrade strength.

Magnetic susceptibility as a proxy for detection of total petroleum hydrocarbons in contaminated wetlands.

Soil petroleum hydrocarbon contamination in the wetlands could cause ecological risk, especially through leakage into water reservoirs. So, the detection of the spatial variability of total petroleum hydrocarbons (TPH) in these soils is very crucial. The variability of TPH and its associations with magnetic susceptibility (χlf) in contaminated soils around the Shadegan pond in southern Iran was investigated. TPH varied from 2.1 to 18.1% (w/w), by the variation of χlf from 14.08 to 713.93 × 10-8 m3kg-1. The highest variability (coefficient of variation, CV = 107.12%) was obtained for χlf indicating significant impacts of magnetic minerals induced by crude oil contamination. High positive correlations were detected among TPH, χlf, and different forms of iron (Fed: extracted by CBD, Feo: extracted by oxalate, and Fet: total iron). The results of mineralogy by powdery XRD and scanning electron microscopy (SEM), also revealed the formation of ferrimagnetic minerals (magnetite, maghemite) during the biodegradation of petroleum hydrocarbons. The stepwise multiple regression analysis showed that χlf and Fed made a great contribution and could explain about 74% of TPH variability in the studied sites. For the extension of this cost-effective and rapid technique, further work is needed to assay saturation isothermal remnant magnetization and isothermal remanet magnetization in contaminated sites.

Bioaugmentation enhance the bioremediation of marine crude oil pollution: Microbial communities and metabolic pathways.

Bioaugmentation is an effective strategy used to speed up the bioremediation of marine oil spills. In the present study, a highly efficient petroleum degrading bacterium (Pseudomonas aeruginosa ZS1) was applied to the bioremediation of simulated crude oil pollution in different sampling sites in the South China Sea. The metabolic pathways of ZS1 to degrade crude oil, the temporal dynamics of the microbial community response to crude oil contamination, and the biofortification process were investigated. The results showed that the abundance and diversity of the microbial community decreased sharply after the occurrence of crude oil contamination. The best degradation rate of crude oil, which was achieved in the samples from the sampling site N3 after the addition of ZS1 bacteria, was 50.94% at 50 days. C13 alkanes were totally oxidized by ZS1 in the 50 days. The degradation rate of solid n-alkanes (C18-C20) was about 70%. Based on the whole genome sequencing and the metabolites analysis of ZS1, we found that ZS1 degraded n-alkanes through the terminal oxidation pathway and aromatic compounds through the catechol pathway. This study provides data support for further research on biodegradation pathways of crude oil and contributes to the subsequent development of more reasonable bioremediation strategies.

Alterations in Hepatocellular, Reproductive, and Oxidative Stress Parameters in Female Albino Rats Exposed to Crude Oil

Aim: To study the effect of exposure to crude oil on the liver, ovary, and some oxidative stress parameters in albino rats.&#x0D; Study Design: A total of 50 female albino rats were used in the experiment. The rats were grouped into three: The control group which consisted of 10 rats, the low dose group which consisted of 20 rats, and the high dose group also consisted of 20 rats. The low dosage group was orally administered 1.5 mL crude oil mixed with 300 grams of rat feeds (0.005 mL/g) and the high dosage group was orally administered 3.0 mL crude oil mixed with 300 grams of rat feeds (0.01mL/g), while the control group was fed with normal rat feeds. The treated feeds were given once a day for 35 days.&#x0D; Place of Study: The study was carried out in the Department of Medical Laboratory Science, Rivers State University, Port Harcourt, Nigeria.&#x0D; Methodology: On the 36th day, the rats were sacrificed and then 5mL of blood from each rat was collected by cardiac puncture into labeled lithium heparin bottles for liver enzymes assay, hormonal assay, and oxidative stress parameters assay, while the livers and ovaries were harvested and fixed in 10% formal saline before tissue processing and histological examinations using H&amp;E staining technique. The collected blood specimens were spun; the plasma was extracted and analyzed in the laboratory for Aspartate aminotransferase (AST), Alanine aminotransferase (ALT), Alkaline Phosphatase (ALP), follicle Stimulating hormone (FSH), luteinizing hormone (LH), Prolactin, Malondialdyde (MDA), and Superoxide dismutase (SOD). Statistical analysis was performed using Graphpad prism version 8.02.&#x0D; Results: Significantly higher plasma levels of AST, ALT, and MDA in the treated groups, except for ALP which was only significantly higher in the high-dose group. FSH, LH, Prolactin, and SOD indicated significantly lower levels in the crude oil-treated rats. The histological examinations showed marked distortion in the architecture of the livers and ovaries of the treated groups, also, there was a reduction in ovarian cellularity and massive degenerated tissues.&#x0D; Conclusion: It is shown that exposure to crude oil contaminants orally could have a significant effect on the plasma level of hepatocellular enzymes, reproductive hormones, and oxidative stress parameters which in turn could lead to hepatocellular dysfunction, infertility, or impaired reproduction in mammals and cellular injuries caused by excess free radicals as signaled by plasma level of oxidative stress parameters.

The influence of oil exploitation on the degradation of vegetation: A case study in the Yellow River Delta Nature Reserve, China

Crude oil is harmful to plants when it is leaked into the soil. The influence of oil exploitation on the degradation of vegetation is still unclear. Oil wells in the Yellow River Delta Natural Reserve (YRDNR) is an ideal region for the research of oil exploitation on vegetation given that this region is less influenced by other human activities. Field investigation and high-resolution remote sensing images were employed to explore the effect of oil exploitation on vegetation. Eighteen sample quadrats and three vegetation sampling strips were investigated near the oil wells. The total petroleum hydrocarbon (TPH) concentrations of the soil affected soil water content negatively. The water content of the sampled soil exhibited a significant positive effect on the species number, Shannon–Wiener index, and aboveground biomass (AGB) of the vegetation. Furthermore, crude oil contamination lowered plant height and quantity, and plant tolerance to crude oil pollutants differed across various species. Oil production has an impact range of 40 m on the surrounding vegetation. Two indices (Normalized Difference Vegetation Index (NDVI) and New Normalized Difference Water Indices 1 (NNDWI1) were employed in a high-resolution remote sensing image interpretation experiment to identify ground objects, the overall accuracy improved 11% compared with the NDVI utilization approach. Moreover, there existed an excellent linear regression relationship between NDVI and field investigated AGB (R 2 = 0 . 813 ). The degradation rate of AGB caused by oil exploitation, directly and indirectly, was about 16.49% in the YRDNR. • TPH indirectly affect species diversity and biomass of vegetation through soil water content. • The combined use of NDVI and NNDWI1 improved 11% of the image interpretation accuracy. • There existed an excellent linear regression relationship between NDVI and AGB. • The impact range of oil production on the surrounding vegetation is about 40 m. • The degradation rate of AGB caused by oil exploitation is about 16.49% in the YRDNR.

Vicia faba seed: a bioindicator of phytotoxicity, genotoxicity, and cytotoxicity of light crude oil.

Crude oil contamination is a serious threat to the environment and human health as it can contaminate food chains. Therefore, it is necessary to find efficient tests to monitor soils for crude oil contamination. The present study investigates the efficacy of Vicia faba seeds for monitoring contaminated soils with light crude oil. Vicia faba seeds were planted in 0 (control), 1, 2, and 4 percentages (weight percentage) light crude oil-contaminated soils. The seed germination and root length were measured to evaluate phytotoxicity, while the mitotic index, chromosome aberrations, and micronucleus formation in the root tip cells were examined for cytotoxicity and genotoxicity tests. The results showed that light crude oil had toxic effects on Vicia faba growth characteristics, even at 1% contamination. The phytotoxicity assay showed that crude oil reduced seed germination and root length by 45% and 61.67%, respectively. In contrast, cellular observations indicated an increase in mitotic index, chromosome aberrations, and micronucleus formation up to 3, 3.59, and 5.6 times, respectively, compared to the control. The light crude oil at 4% induced the simultaneous occurrence of nuclear bud, polyploidy, and micronucleus that may be considered as severe clastogenic and aneugenic effects. Accordingly, Vicia faba can be considered a reliable living system for monitoring light crude oil pollution in soils, even at low concentrations.

Application of multiple linear and polynomial regression in the sustainable biodegradation process of crude oil

Statistical regression models have been applied in various biotechnical applications to determine the relationship between response and conditional factors as well as to facilitate prediction. This research focuses on sustainable biodegradation process of crude oil using native and recombinant microbial strains to alleviate the significant environmental threat posed by crude oil contamination. This sustainable process is energy and cost-efficient compared to the traditional measures adopted in the extermination of the contaminated soil due to crude oil. The reaction of the wild and recombinant microbial strains to biodegradation rate was detected in the experimental study. These experimental data were used to develop multiple linear regression (MLR) and polynomial regression models (PR). The coefficient of determination, or R2 value, was used to validate the constructed models. The PR model had a high R2 of 0.863, whereas the MLR model had a low value of 0.495. The PR model provided the best match, and it also explains the impact of conditioning factors on the biodegradation rate. To summarize, the recombinant microbial strain yielded a better biodegradation rate with increasing incubation days at lower crude oil contents.

ORGANIC MATTER AND PHYSICAL PROPERTIES OF CRUDE OIL CONTAMINATED SOIL AMENDED WITH TERMITE SOIL AND BLUE PORTER PLANT

Crude oil contamination in the Niger Delta has become a serious problem for soil health and agricultural production. We hypothesized that applying Trinervitermes spp of termite soil and introducing the Blue porter plant (Stachytarpheta jamaicensis) to crude oil contaminated soil can accelerate microbial activities and improve the soil's physical properties and organic matter content. A field experiment was carried out on a 0.02 ha land to assess the effects of Trinervitermes geminatus termite soil and Stachytarpheta jamaicensis plant on the physical properties of a sandy loam soil contaminated with crude oil in the Niger Delta of Nigeria. The experiment was arranged in a Randomized Complete Block Design (RCBD), consisting of 13 treatments in 3 replications. The soil was contaminated with 4% crude oil (equivalent of 40,000 mg kg-1) (Cr4) and 5% crude oil (equivalent of 50,000 mg kg-1) (Cr5), in single application. The soil was treated with 10 and 20 t ha-1 of Trinervitermes geminatus termite soil (10Mo and 20Mo, respectively), alone and in combination with Blue porter plant (Stachytarpheta jamaicensis). Results revealed that 6-month applications of Trinervitermes geminatus termite soil and Stachytarpheta jamaicensis plant have significant effects on physical properties and Soil Organic Matter SOM) Applying 10 and 20 t ha-1 of termite soil in combination with Stachytarpheta jamaicensis plant to 4% crude oil increased SOM from 29 g kg-1 in the control plots to about 61 g kg-1 after 6 months. The application of 20 t ha-1 termite soil to 4% crude oil (Cr4+20Mo) reduced soil bulk density, increased saturation water content by 15%, and saturated hydraulic conductivity (Ksat) from zero to 1.67 and 1.53 cm h-1 in 6 months, after the application compared to the untreated Cr4 soil. Macro-aggregates &gt; 0.25 mm were generally higher in the termite soil alone and in combination with the Blue porter plant. Micro-aggregates &lt;0.25 mm dominated the Control plot (54 and 46% after 3 and6 months). Water stable aggregates in 4.75-2.0 mm size class increased from 22% to 56% for Cr5+20mo after 6 months. The termite soil improved the macro-aggregates, while the Blue porter plants improved Ksat of the soil after 6 months.

Correlation of soil microbiome with crude oil contamination drives detection of hydrocarbon degrading genes which are independent to quantity and type of contaminants

The impacts of crude oil contamination on soil microbial populations were explored in seven different polluted areas near oil and gas drilling sites and refineries of Assam, India. Using high-throughput sequencing techniques, the functional genes and metabolic pathways involved in the bioconversion of crude oil contaminants by the indigenous microbial community were explored. Total petroleum hydrocarbon (TPH) concentrations in soil samples ranged from 1109.47 to 75,725.33 mg/kg, while total polyaromatic hydrocarbon (PAH) concentrations ranged from 0.780 to 560.05 mg/kg. Pyrene, benzo[a]anthracene, naphthalene, phenanthrene, and anthracene had greater quantities than the maximum permitted limits, suggesting a greater ecological risk, in comparison to other polyaromatic hydrocarbons. According to the metagenomic data analysis, the bacterial phyla Proteobacteria, Actinobacteria, Acidobacteria, and Bacteroides were the most prevalent among all polluted areas. The most prominent hydrocarbon degraders in the contaminated sites included Burkholderia, Mycobacterium, Polaromonas, and Pseudomonas. However, the kinds of pollutants and their concentrations did not correlate with the abundances of respective degrading genes for all polluted locations, as some of the sites with little to low PAH contamination had significant abundances of corresponding functional genes for degradation. Thus, the findings of this study imply that the microbiome of hydrocarbon-contaminated areas, which are biologically involved in the degradation process, has various genes, operons and catabolic pathways that are independent of the presence of a specific kind of contaminant.

Occurrence and Uptake of Heavy Metals in Soil and Plant (Tomato) Associated with Crude Oil Contamination

The general increase of heavy metal content in the soil has been largely caused by crude oil spillage. This study investigates the possibility of tomato (Lycopersicon esculentum Miller) to sorb heavy metals present in crude oil. Crude oil of 0 mL (control), 75 and 150 mL were mixed thoroughly with 15 kg of loamy soil (dry weight) in perforated plastic buckets, as the experimental pots and left for 4 days before transplanting tomato seedlings. After 12 weeks of transplanting, heavy metals analysis was carried out on plant’s fruits, leaves, stems and roots. Physicochemical analyses show that control soil had the lowest organic carbon (3.07 %) while 150 mL had the highest mean organic carbon content (8.24 %). The silt, clay and sand constituents were not significantly different (p &gt; 0.05) in both treated and untreated soil. The control had the least pH value (6.1) while the lead (Pb) content in soil was highest in 150 mL (0.33 mg/kg) but was not significantly different (p &gt; 0.05) from control (0.26 ) and 75 mL (0.30 mg/kg). Lead (Pb) and Cadmium (Cd) were not detected in leaves and fruits. However, bioaccumulation factor (BAF) of Cd and Ni in stem were greater than 1. Although, the concentrations of these heavy metals falls below toxic levels, its consumption could lead to adverse health effects in both man and animals through bioaccumulation or biomagnification.&#x0D; HIGHLIGHTS&#x0D; &#x0D; Countries with poor hydrocarbon pollution regulation are more challenging with oil spills, either through accidental discharges or indiscriminate disposal of hydrocarbon waste&#x0D; Plants essentially need some metals such as iron, copper among others, for their growth and other metabolic activities. However, at excess of specific limits, these metals adversely affect plant growth&#x0D; In this study, bioaccumulation factors (BAF) of Cd and Ni in the stem were greater than 1, this shows that the tomato plant is a hyperaccumulator of Cd and Ni from the soil&#x0D; &#x0D; GRAPHICAL ABSTRACT

Bioremediation Potential of Selected Rhizosphere Fungi of Tridax Procumbens Linn. and Chromolaena odorata (L.) R.M. King &amp; H. Rob

Co-metabolism between plants and rhizosphere microbes is the mainstay of rhizoremediation of contaminated soils. The aim of the current study was to isolate and screen selected rhizosphere micro-fungi of two Asteraceae (Tridax procumbens and Chromolaena odorata) collected from the wild in University of Lagos, Akoka, Lagos State for bioremediation potential. Rhizosphere fungi were isolated, identified and evaluated for crude oil myco-remediation. The inhibitory effect of different concentrations of crude oil on mycelial growth of the most abundant fungi was determined with poisoned plate assay method. The most abundant and recurring fungi around C. odorata and T. procumbens were determined using the serial dilution and plating methods. Analysis of the rhizosphere soil of T. procumbens and C. odorata showed they were sandy loam type. C. odorata soil had higher moisture, organic carbon, and acid content than T. procumbens. Aspergillus flavus and Trichoderma harzianum were the most abundant and recurring fungi in C. odorata and T. procumbens, respectively. Thirty-nine micro-fungi belonging to twenty genera were isolated from the test plants’ rhizosphere. A. flavus and T. harzianum tolerated 2.50 to 10.00% crude oil contamination assessed with their mycelial growth inhibition reducing with time. A. flavus and T. harzianum caused a 68.45% and 86.71% reduction of crude oil contamination respectively, in a time dependent manner. The filamentous fungi ~A. flavus and T. harzianum can potentially be used to simultaneously ameliorate crude oil contaminated soils in conjunction with C. odorata and T. procumbens, respectively in the innovative technology termed rhizoremediation.

Bacterial Isolates from Greek Sites and Their Efficacy in Degrading Petroleum

Polycyclic aromatic hydrocarbons (PAHs) are a major organic pollutant, not only because they do not self-degenerate but also because they accumulate in the food chain and give rise to serious repercussions in terms of biodiversity sustainability. Petroleum-degrading bacteria have long been used as a promising solution in the effort to biodegrade crude oil. In this study, new isolates from specific Greek environments displaying various levels of crude oil contamination, as well as isolates belonging to the ATHUBA collection, were thoroughly investigated for their capacity to degrade crude oil. Furthermore, the presence of nahH and alkJ genes in the above bacterial isolates, as well as their ability to form agglomerates or release surfactants, was investigated. Two consortia were formed, and their ability to degrade crude oil was tested, achieving similar degrading capacities as those observed with the individual strains. A Pseudomonas plecoglossicida isolate demonstrated the highest percentage (76.7%) ability to degrade crude oil. The biodegradation rate of this isolate was further evaluated by measuring the alkanes/hopanes ratio over a period of ten days, exhibiting a higher degradation rate in short-chain (C11–C21) alkanes, whereas a decrease in the ratio was observed when the number of carbons in petroleum increased. This is the first detailed report on bacterial communities in oil-polluted areas of Greece that contain a variety of bacteria with the ability to degrade PAHs in contaminated sites and may provide a novel alternative to various bioremediation processes or be used as inocula in autochthonous bioaugmentation procedures for crude oil biodegradation.

Microbiome profile of soil and rhizosphere plants growing in traditional oil mining land in Wonocolo, Bojonegoro, Indonesia

Traditional oil mining poses negative effects on the environment through pollution with crude oil. One of the traditional mining sites in Wonocolo, Bojonegoro, Indonesia was reported to contaminate the surrounding area with a high level of crude oil. Therefore, this study aims to examine the microbiome profiles of contaminated soil and the rhizosphere of naturalized plants growing at the sites. It was conducted in Wonocolo, Bojonegoro to obtain an insight into the possible remediation efforts of using indigenous hydrocarbon-degrading bacteria and naturalized plants as in situ remediation agents. The results showed that the soil located close to the oil well-contained a high level of crude oil at 24.8%, and exhibited a distinct microbiome profile compared to those located further which had lower crude oil contamination of 14.15, 10.89, and 4.9%. Soil with the highest level of crude oil contamination had a comparatively higher relative abundance of assA, an anaerobic alkene-degrading gene. Meanwhile, the rhizosphere of the two naturalized plants, Muntingia calabura, and Pennisetum purpureum, exhibited indifferent microbiome profiles compared to the soil. They were found to contain less abundant hydrocarbon-degrading genes, such as C230, PAH-RHD-GP, nahAc, assA, and alkB suggesting that these naturalized plants might not be a suitable tool for in-situ remediation.

Assessment of Mechanical Properties of Soil-Lime-Crude Oil-Contaminated Soil Blend Using Regression Model for Sustainable Pavement Foundation Construction

Oil pollution causes deterioration of the physical, chemical, mechanical, and geotechnical characteristics of affected soil leading to loss of soil productivity for engineering purposes. Different stabilization methods serve as a remedy for such soil to regain its loss engineering properties. This study was concerned with the utilization of lime to stabilize crude oil contaminated soil and to investigate its efficacy for soil stabilization. The study also focused on determining the geotechnical properties of crude oil contamination and matching the result with standard specifications established for engineering works. Hydrated lime, expansive clayey soil, contaminated soil, and potable water were the materials used for the experimental investigation. The contaminated soil was treated with 6.5% lime and 0–20% crude oil contaminated materials obtained from oil exploration sites in North-Eastern Nigeria and per standard test method for laboratory evaluation of consistency limits, compaction properties, California bearing ratio (CBR), and microstructural and mineralogical assessments. The experimental results obtained were further tested statistically through one-way ANOVA and F-statistics to establish the source of variation for the geotechnical properties, while multiple linear regression and correlation statistics helped draw the connection between the consistency limits, compaction, and CBR properties of the soil-lime-COCM blend. Results indicated a coefficient of determination of 99.86. The contaminated soil materials were found to show optimal performance at a 5% ratio and 6.5% of lime for civil construction purposes.

Application of near infrared spectroscopy in sub-surface monitoring of petroleum contaminants in laboratory-prepared soils

ABSTRACT This study was conducted to determine the suitability of near-infrared (NIR) spectroscopy for subsurface monitoring of crude oil contaminants in different soil types under different moisture conditions. Calibration tests, carried out in both wet and dry soils, with crude oil contents 5–30% indicate an inverse relationship between spectra and oil content with R2 values ≥0.98 for dry soil mixtures. A derived index termed “Oil Index” was generated by calculating a spectral ratio between the main oil peak in the NIR region and a spectrally inactive part of the spectrum within the visible region. It was used in a series of experiments designed to test whether NIR probes could yield useful information about the movement of oil through different soils. Synthetic crude oil was dropped into a series of soil samples of different particle size distribution and moisture content. Analyses of the 3D distribution of values of the Oil Index demonstrate that it is possible to estimate and map synthetic crude oil concentration in the subsurface of the soil samples. Results showed that while the Oil Index provided a reasonable estimation for oil concentration in dry samples, this was not the case for wet samples, although the Index was useful in understanding the pattern of movement of oil contaminant in wet soils. The work indicates that this technique may enhance field investigation of oil contamination, providing an accurate in-field technique.

Sound Productivity of Spiny Lobster Panulirus homarus (Linnaeus, 1758) due to Crude Oil Contamination

Anthropogenic activities have the potential to put pressure on the marine environment. Crude oil was one of the pressure that give rise to any response of the aquatic organism, such as sound. This study aimed to analyze the sound productivity of spiny lobster Panulirus homarus (Linnaeus, 1758) in waters contaminated with crude oil. Observation of lobster sound was carried out on a laboratory scale using the passive acoustic method. A hydrophone and Closed Circuit Television (CCTV) camera coupled with a decoder and personal computer used to record the movements and sounds of P. homarus during the treatment of crude oil at concentrations 1; 5; 10 and 100 mgL-1. The result showed that crude oil contamination in water was impacted the sound productivity of P. homarus. In the low concentration of crude oil (1 - 5 mgL-1), P. homarus was responded with more sound produced. Afterwar, until concentration off 10 mgL-1, the response of P homarus showed different between individuals. In the 100 mgL-1 concentration, the sound productivity of all P. homarus was decreased. Based on this study, we concluded that the sound of P. homarus has the potential as an indicator of water pollution.Keywords: Panulirus houmarus, crude oil, fish sound