Total Hydrocarbon Content Research Articles

Emission control in a dual fuel low temperature combustion engine at intermediate loads

Intermediate to high load operation in dual fuel reactivity controlled compression ignition (RCCI) techniques is restricted due to uncontrolled combustion that causes engine knocking. Dual fuel strategies with advanced pilot injection and near-top dead center (TDC) main injection timings are reported to enhance combustion control, albeit with increased soot emissions, reduction of thermal efficiency, and emergence of an intricate trade-off between total hydrocarbon (THC) and oxides of nitrogen (NOx) emissions. In order to address these conflicting issues, an intermediate engine load, corresponding to 6 bar gross indicated mean effective pressure at 1500 and 2200 rev/min engine speeds was investigated in this work. The main objectives of this work are (1) to obtain combination of control parameters to achieve near-zero engine-out NOx and soot emissions and high thermal efficiency while minimizing THC and CO emissions; (2) to understand the effectiveness of diesel oxidation catalysts (DOCs) for the oxidation and reduction of exhaust gas species in the dual fuel mode; and (3) to understand the oxidation characteristics of the soot generated from the dual fuel mode. Optimum dual fuel low temperature combustion strategies, in terms of diesel injection timings, quantity and exhaust gas recirculation levels, were identified using the statistical multi response signal to noise (MRSN) ratio method in which NOx, soot and indicated efficiency were response variables. The performance of commercial DOCs, with different precious metal (Pt and/or Pd) loadings, were also studied at optimum dual fuel strategies for gasoline-diesel dual fuel operations. High DOC outlet temperatures (>∼340°C), due to the exotherm generated by the oxidation of high concentrations of THC and carbon monoxide (CO) emissions from dual fuel operations, resulted in greater than 90% THC conversion efficiency. The exotherm decreased the nitric oxide (NO) oxidation whereas the nitrogen dioxide (NO2) reduction reactions were favored over the DOC in the dual fuel mode at the intermediate load operating condition. Thermogravimetric analysis of the soot showed higher activation energy (177.2 kJ/mol), formed at the dual fuel optimum condition, relative to the activation energy (162.7 kJ/mol) of the soot formed in conventional diesel combustion (CDC).

Evaluation of hydrocarbon degrading potentials of cellulolytic edaphic borne fungi

This study assessed the hydrocarbon degradative potentials of cellulolytic fungi cultured from top soil samples within Benin City, Edo State. Soil samples were collected from 3 sites; a farmland, a fallow plant covered land, and municipal dumpsite. Physicochemical parameters of the soil samples were based on standard methods. Standard cultural and molecular techniques were used to isolate and identify fungi present in samples. Cellulolytic activity of fungal isolates was determined with Czapek-dox agar supplemented with 0.1% sodium carboxymethyl cellulose (CMC). Cellulolytic fungi were subsequently screened for the ability to utilize blended petroleum as sole carbon source. Further, two isolates having the highest optical density were used for growth profile study as axenic culture and in consortium. The growth profile study assessed pH, optical density, total petroleum hydrocarbon content and fungal dry mass. Results showed that the organic carbon value of the top soils ranged from 4.14 g/kg ± 0.55 to 8.56 g/kg ± 0.05. All collected soil samples were sandy, while total hydrocarbon content ranged from 0.38 g/kg ± 0.04 to 1.13 g/kg ± 0.01. The mean fungal counts were highest in dumpsite soils and ranged from 4.0 × 103 cfu/g ± 1414 to 7.0 × 103 cfu/g ± 1003. Eight fungal isolates with cellulolytic properties were identified from the soil samples. Trichosporon asahii and Curvularia bothriochloae had highest (p < 0.05) OD when grown on blended petroleum and were used for growth profile studies. OD was highest (p < 0.05) in C. bothriochloae (0.372 ± 0.0005) relative to T. asahii and the consortium at 15 d. THC reduced significantly (p < 0.05) in both axenic cultures and the consortium after 15 days, while fungal biomass was highest (p < 0.05) in consortium relative to axenic cultures after 15 d. This study showed hydrocarbon degrading capabilities of cellulolytic fungi from different top soils.

Evaluation of the Ability of Ameliorants to Influence the Biological Indicators and Hydrophobicity of Oil-Contaminated Haplic Chernozems

ABSTRACT The aim of the study was to assess the ameliorants effect on the biological parameters and Haplic Chernozems hydrophobicity. In model experiment conditions, Haplic Chernozem was polluted by oil and remediation with application of nitroammophos, Sodium humate, biochar, and Baikal EM-1 was simulated during to 30, 90, and 180 days. Indicators of soils activity – germination and intensity indicators of initial seed growth, the activity of catalase and dehydrogenases, the total number of bacteria, hydrophobicity were studied. On the 30 and 90th days after remediation, the most significant reliable decrease in oil regarding was promoted by 2 D biochar. After 180 days of dose 1 D and dose 2 D nitroammophos, as well as 1 D Baikal EM-1, the total petroleum hydrocarbon content was reduced significantly. Baikal EM-1 and biochar contributes to the greatest decrease in hydrophobicity at all periods of the experiment to a greater extent. On the 30th day, the introduction of nitroammophos, biochar, and 1 D Sodium humate contributed to an increase in the integral indicator of the biological state of oil-contaminated Haplic Chernozem, on the 90th day, the introduction of all doses of biochar led to an increase in the indicator, and on the 180th – all doses of Baikal EM-1, and 0.5 D Sodium humate. The research results may be used when choosing a method of soil restoration after oil pollution.

Synergistic use of cattle bile, compost and fertilizer amendments in enhancing the bioremediation of hydrocarbon-contaminated soils

This study investigated the degradation of hydrocarbon-contaminated soil using compost, NPK 20:10:10 fertilizer, and cattle bile as biostimulants. In this study, 1000 g of homogenized contaminated soil was amended with 10.50 g of NPK fertilizer and 107.50 g of compost to achieve a nitrogen concentration of 0.2 %. To establish a 0.4 % nitrogen concentration, 23.90 g of NPK fertilizer, 243.54 g of compost, and 2 ml of cattle bile were used. These amendments were applied in various combinations to create the following microcosm treatments: A, B, C, D, A2, B2, C2, D2, and a control. The microcosms, along with the control were incubated for 6 weeks in triplicate. Throughout this period, several parameters were monitored every two weeks, including pH, nitrogen (N), potassium (K), phosphorus (P), moisture content, organic carbon, organic matter, total heterotrophic bacterial count (THBC), and total petroleum hydrocarbon (TPH) concentration. The results showed significant differences (p < 0.05) in TPH content across the microcosms during the four sampling periods. By the end of the 6-week incubation, the TPH residual concentration varied between 1.58 mg kg-1 and 20.61 mg kg-1, corresponding to degradation rates of 98.43 % and 79.58 %, respectively, from an initial TPH concentration of 100.91 mg kg-1. Microcosm B2 demonstrated the highest hydrocarbon removal efficiency (98.43 %), while the control showed the lowest efficiency. The order of degradation efficiency among the microcosms was B2 > B (94.89 %) > C (94.64 %) > A (94.13 %) > D2 (93.62 %) > A2 (93.51 %) > C2 (92.45 %) > D (91.44 %). The study also found that pH and nitrogen levels were related to the reduction in hydrocarbon content. Microcosms with a 0.4 % nitrogen concentration showed a higher rate of nitrogen consumption compared to those with a 0.2 % concentration. Additionally, changes in pH were observed as hydrocarbon degradation progressed. This study further applied cluster analysis, Bayesian statistics, and multiple linear regression to evaluate the effects of treatments on soil quality over time. Cluster analysis showed increasing dissimilarity between merged clusters, while Bayesian analysis revealed positive trends in parameter estimates in Weeks 2 and 4. Regression analysis indicated significant impacts of Weeks 2, 4, and 6 on Week 0, with F-statistics of 8.475 (p = 0.016), 9.804 (p = 0.004), and 3.759 (p = 0.037), though multicollinearity reduced the predictive power of individual coefficients. Overall, Microcosm B2 emerged as the most effective treatment option. The findings suggest that biostimulation using a combination of moisture, compost, NPK fertilizer, and cattle bile is an effective approach to achieving high efficiency in TPH degradation in hydrocarbon-contaminated soils.

Optimization of Bioremediation of Crude Oil Polluted Soil through Variation in Moisture Content and Proportion of Augmenting Bacterium and Fungus

Aim: The aim of this study was to enhance bioremediation of crude-oil polluted soil through optimization procedures. Study Design: The Box-Benkhen coded values format and experimental design were used in the design of the study. Place and Duration of Study: The study was carried out in the Microbiology laboratory of the Department of Microbiology, Rivers State University, Nigeria, between February 2024 and July 2024. Methodology: Hydrocarbon utilizing bacteria (HUB) &amp; fungi (HUF) were isolated from crude-oil polluted soil, and screened for hydrocarbon degrading ability (HCDA). HUB and HUF with the highest HCDA were identified and used for bioremediation optimization experiment. In the experiment, different combination of moisture content (MC), and proportion of HUB (pHUB) &amp; HUF (pHUF) were investigated for their effect on extent of hydrocarbon reduction (EoHR). EoHR obtained from the different combinations were fitted using a generalized polynomial model so as to obtain a polynomial equation for predicting EoHR. The equation was used in generating prediction profiles from which the combined values of the 3 parameters that will lead to the highest EoHR was determined. The predicted combined values were implemented in a new setup. A control and a setup enhanced with fertilizer were also prepared. The setups were maintained for 3 weeks. On day 0, 14, and 21 samples were collected and analyzed for total hydrocarbon concentration (THC). Results: The results obtained showed that among the coded isolated HUB and HUF, HB5 and HF1 had the highest HCDA; 36.4% and 4.1% respectively, and were identified phenotypically as Klebsiella ornithinolytica and Aspergillus flavus respectively. The results of the optimization experiment and prediction profiles showed that the highest (68.6%) EoHR was achievable at MC = 20%, pHUB = 10%, and pHUF = 1%. The actual EoHR on day 21 in the optimized, enhanced optimized, and control setups were 60.3, 58.9, and 39.9% respectively. Conclusion: Bioremediation optimization studies is advantageous and should be carried out on crude-oil polluted sites before carrying out bioremediation.

Survival and reproduction tests using springtails reveal weathered petroleum hydrocarbon soil toxicity in boreal ecozone.

Survival and reproduction tests were conducted using two native springtail (subclass: Collembola) species to determine the toxicity of a fine-grained (< 0.005 - 0.425 mm) soil from an industrial site located in the Canadian boreal ecozone. Accidental petroleum hydrocarbon (PHC) release continuously occurred at this site until 1998, resulting in a total hydrocarbon concentration of 12,800mg/kg (soil dry weight). Subfractions of the PHC-contaminated soil were characterized using Canadian Council of Ministers of the Environment Fractions, which are based on effective carbon numbers (nC). Fraction 2 (> nC10 to nC16) was measured at 8400mg/kg and Fraction 3 (> nC16 to nC34) at 4250mg/kg in the contaminated soil. Age-synchronized colonies of Folsomia candida and Proisotoma minuta were subject to 0%, 25%, 50%, 75%, and 100% relative contamination mixtures of the PHC-contaminated and background site soil (< 100mg/kg total PHCs) for 28 and 21days, respectively. Survival and reproduction decreased significantly (Kruskal-Wallis Tests: p < 0.05, df = 4.0) in treatments of the contaminated site soil compared to the background soil. In both species, the most significant decline in survival and reproduction occurred between the 0% and 25% contaminated soil. Toxicity responses in the two springtails were ascribed to the standardized test design, short lifespans, and high fecundity in both species. This study showed that 25 + years of soil weathering has not eliminated the toxicity of fine-grained PHC-contaminated soil on two native terrestrial springtail species. Adverse effects to springtail health were attributed to exposure to soils dominated by genotoxic PHC Fraction 2 compounds and slow weathering processes due to the cold climate at the site.

Heavy Metals, Polycyclic Aromatic Hydrocarbons, Total Petroleum Hydrocarbons and Total Hydrocarbon Contents in Drilling Mud Effluents From Eastern Obolo Oilfield In The Niger Delta Region Of Nigeria

The objective of this paper is to evaluate the concentrations of heavy metals, polycyclic aromatic hydrocarbons (PAHs), total petroleum hydrocarbons (TPH) and total hydrocarbon content (THC) in drilling mud effluents from Eastern Obolo Oilfield in the Niger Delta region of Nigeria using appropriate standard methods. The TPH and THC of OBM and WBM analyses with UV-Vis spectrophotometer indicated 1.60 mg/kg for OBM and 1.30 mg/kg for WBM. A value of 5.35 mg/kg was obtained for OBM compared to 5.15mg/kg for the OBM in the THC. Generally, the result indicated that TPH&lt;THC and was found to be far lower than 50 mg/kg allowable for drilling mud in the environment. GC-MS analysis for TPH indicated a range of n- alkanes with a higher concentration (46118.28 ug/l) in the OBM compared to WBM concentration (17185.95 ug/l) compared to the UV-Vis spectrophotometer. The analysis of TPH using GC-MS revealed a more comprehensive range of n- alkanes present in the OBM and WBM. The heavy metals indicated considerable differences of the concentration in OBM and WBM. The concentrations viewed significantly with the range for the WBM; Fe&gt;Zn&gt;Cr&gt;Pb&gt;Cu&gt;Ni&gt;Cd. The concentrations range in the OBM were; Fe&gt;Cr&gt;Zn&gt;Ni&gt;Cu&gt;Pb&gt;Cd. The evaluation of the concentrations of these elements in drilling mud are of environmental significance from pollution viewpoint especially ferrochrome lignosulphate (Chromium pollution) and lead compounds (lead pollution). The results from this study which indicates the presence of varying concentrations of heavy metals and petroleum hydrocarbons in the drilling mud is valuable and significant when making the choice for subsequent disposal of drilling mud effluents and, particularly in the study area where extensive oil/gas operation is ongoing.

Physicochemical and Fungal Analysis of a Hydrocarbon-Polluted Soil at Amadi-Ama Creek of Bonny River Port Harcourt, Rivers State, Nigeria

Numerous hydrocarbon-utilizing fungal species have been implicated with the ability to utilize/degrade hydrocarbon as carbon source, which indicate their potential for environmental cleanup in hydrocarbon-contaminated sites. In this study, five (5) indigenous fungal species were isolated from a petroleum-hydrocarbon polluted soil at Amadi-ama Creek, Bonny river shoreline, Port Harcourt, Rivers State. These fungal species may have high potential to biodegrade petroleum hydrocarbon pollutants. Samples were collected randomly from the hydrocarbon impacted soil at Amadi-ama Creek, Bonny river shoreline. Sabouraud’s Dextrose Agar (SDA) and Czapek Agar were used as growth media. Samples were examined to assess the physical and chemical characteristics such as conductivity, pH, temperature, nitrate, iron, copper, zinc, chromium, phosphate, sulphate, total hydrocarbon content, total petroleum hydrocarbon, and polycyclic aromatic hydrocarbon. These parameters are known to influence the occurrence, diversity and distribution of microorganisms in an ecological niche. Soil pH showed to be acidic (6.21), result also showed that Total hydrocarbon content, Total petroleum hydrocarbon and Polycyclic aromatic hydrocarbon values were at 306.55mg/kg, 112.134mg/kg, 44.227mg/kg respectively establishing the incidence of hydrocarbon pollution. Electrical conductivity and Temperature were at 1250 Us/cm, and 29.580C respectively while Nitrate, Phosphate, Sulphate, Iron, Copper, Zinc, and Chromium values were at 1.228mg/kg, 0.751mg/kg, 20.214mg/kg, 18.431mg/kg, 0.113mg/kg, 0.121mg/kg, and 0.042mg/kg respectively. Monitoring of the soil quality established the incidence of hydrocarbon pollution as well the incidence of anthropogenic influence on the soil putting into cognizance human activities at the shoreline. Morphological identification of obtained fungal species led to their assignment into four (4) genera and five (5) species; Aspergillus niger (28%), Aspergillus flavus (22%), Cladosporium herbarum (20%), Penicillium notatum (17%), Fusarium spp (11%). The predominance of Aspergillus isolates (28% and 22%) in this study could be a pointer to their potential to utilize hydrocarbon as their sole source of nutrient. The isolation of these indigenous fungal species could serve as a baseline study on which further analysis such as hydrocarbon degradation screening test could determine their individual hydrocarbon degradation potentials and subsequent consideration as hydrocarbon degrading microbes in subsequent bioremediation study.

Quantitative expression of LNAPL pollutant concentrations in capillary zone by coupling multiple environmental factors based on random forest algorithm

The capillary zone plays a crucial role in migration and transformation of pollutants. Light nonaqueous liquids (LNAPLs) have become the main organic pollutant in soil and groundwater environments. However, few studies have focused on the concentration distribution characteristics and quantitative expression of LNAPL pollutants within capillary zone. In this study, we conducted a sandbox-migration experiment using diesel oil as a typical LNAPL pollutant, with the capillary zone of silty sand as the research object. The variation characteristics of LNAPL pollutants (total petroleum hydrocarbon) concentration and environmental factors (moisture content, electrical conductivity, pH, and oxidationreduction potential) were essentially consistent at different locations with the same height. These characteristics differed within range of 10.0–50.0 cm and above 60.0 cm from groundwater. A model for quantitative expression of concentrations was constructed by coupling multiple environmental factors of 968 sets-7744 data via random forest algorithm. The goodness of fit (R2) for both training and test sets was greater than 0.90, and the mean absolute percentage error (MAPE) was less than 16.00 %. The absolute values of relative errors in predicting concentrations at characteristic points were less than 15.00 %. The constructed model can accurately and quantitatively express and predict concentrations in capillary zone.

International airport emissions and their impact on local air quality: chemical speciation of ambient aerosols at Madrid–Barajas Airport during the AVIATOR campaign

Abstract. Madrid–Barajas Airport (MAD) is the fourth-busiest airport in Europe. The aerosol chemical composition and the concentrations of other key pollutants were measured at the airport perimeter during October 2021 to assess the impact of airport emissions on local air quality. A high-fidelity ambient instrumentation system was deployed at Madrid–Barajas Airport to measure the following: concentrations of organic aerosols (with their composition), black carbon (eBC), carbon dioxide (CO2), carbon monoxide (CO), nitrogen dioxide (NOx), sulfur dioxide (SO2), particulate matter (PM2.5, PM10), total hydrocarbon (THC), and total particle number. The average concentrations of eBC, NOx, SO2, PM2.5, PM10, CO, and THC at the airport for the entire campaign were 1.07 µg m−3, 22.7 µg m−3, 4.10 µg m−3, 9.35 µg m−3, 16.43 µg m−3, 0.23 mg m−3, and 2.30 mg m−3, respectively. The source apportionment analysis of the non-refractory organic aerosol (OA) using positive matrix factorisation (PMF) allowed us to discriminate between different sources of pollution, namely less oxidised oxygenated organic aerosol (LO-OOA), alkane organic aerosol (AlkOA), and more oxidised oxygenated organic aerosol (MO-OOA). The results showed that LO-OOA and MO-OOA account for more than 80 % of the total organic particle mass measured near the runway. Trace gases correlate better with the AlkOA factor than LO-OOA and MO-OOA, indicating that AlkOA is mainly related to primary combustion emissions. Bivariate polar plots were used for pollutant source identification. Significantly higher concentrations of the obtained factors were observed at low wind speeds (&lt;3 m s−1) from the southwest, where two of the runways and all terminals are located. Higher SO2/NOx and CO/eBC ratios were observed when the winds originated from the northeast, where the two northern runways are located. These elevated ratios are attributed to the aircraft activity being the major pollutant source in the northeast area.

Green transformation of oily sludge through geopolymer: Material properties and hydration mechanisms

Oily sludge (OS) is a kind of hazardous waste generated from the petrochemical industry. Currently, pyrolysis has been widely applied for OS disposal, while low-oil content (<5 wt%) OS still lacks novel technology to achieve efficient resource utilization and harmful substances immobilization. In this study, a kind of OS-based geopolymer was developed by OS and ground granulated blast furnace slag (GGBS). The results showed that in geopolymer with 30 wt% OS, the content of total petroleum hydrocarbons (TPHs) decreased by 82%, Zn achieved 100% stabilization, and the 28 d compressive strength could still reach 32.8 MPa. The appropriate oil content filled the pores and cracks in geopolymer matrix. The constructed model compounds further elucidated the hydration mechanisms of OS-geopolymer. The nucleation effect of crude oil and micro-aggregate effect of minerals jointly improved the polymerization degree of C-(A)-S-H gels. OS promoted the transformation of [SiO4]4− monomers into C-(A)-S-H unbranched middle groups and three-dimensional networks, thereby efficiently stabilizing harmful substances. Sustainability analysis showed that OS-based geopolymer had good environmental and economic benefits. Overall, this work provides theoretical guidance for the green transformation of OS in the construction field.

Investigation of the utilization of forest woodchips in a commercial small-scale open-top gasifier

The present work investigates the gasification of forest woodchips, which also contain needles, branches and cones, in an 85-kW open-top gasifier with 60 %–100 % load. This lower quality fuel has higher contents of ash, bark and fines compared to typical requirements of commercial small-scale gasifiers. The woodchips were utilized in unsieved and sieved (>10 mm) fraction. By using gas analysis and temperature measurements at a high local and temporal resolution, three main novel results were found: 1) The results of this work confirm that preferential paths in the fuel bed, caused by the fines content, led to a worse gas quality. The positive effects of a load reduction (i.e., increasing hydrogen and decreasing tars contents) were not found with the unsieved fuel. 2) Opposite trends for the methane concentration with the load were found with unsieved and sieved fuel. The preferential paths probably prevented the complete decomposition of longer-chain hydrocarbons and increased the intermediate product methane, while the non-methane hydrocarbon content reduced at a similar rate with both fuel fractions. 3) When using unsieved fuel, reducing the load massively decreased the fluctuations of the air mass flow and the total hydrocarbon content. With sieved fuel, however, a satisfying process stability was already achieved in all loads. Therefore, an appropriate load management was identified to enable the utilization of fuels with higher fines contents. With these new findings, forest chips in unsieved and sieved form can be successfully used in small-scale open-top gasification.

Catabolic gene indices of hydrocarbon diminution in Ultisol treated with cropped Bacillus altitudinis-amendments

This study evaluated catabolic gene expression as an index of hydrocarbon breakdown in ultisol treated with Bacillus altitudinis-Cropped Biofertilizers derived from Biosolid and Brewer Spent Grain (BSG) using phenotypic and molecular methods. We observed significant reductions in Total Petroleum Hydrocarbons (TPH) concentrations with both amendments, albeit the biosolid based amendment was markedly more effective. Concurrently, there was a substantial increase in hydrocarbon-degrading bacteria. Notably, the bulk of Operational Taxonomic Units (OTUs) in biosolid (95.77 %) and BSG (93.00 %) amended Ultisol were Proteobacteria, Acidobacteria, Actinobacteria, and Planctomycetes, which are key players in hydrocarbon bioremediation. We observed the presence of eleven hydrocarbon-degrading genes through M5nr analysis. These genes encompass essential catalysts for aliphatic hydrocarbon degradation and hydrocarbon desulfurization. Notably, these enzymes/genes include Bacterial Flavin-bound Monooxygenase (AlmA), Alkane Monooxygenase (AlkM), Alpha Ketoglutarate Dependent Dioxygenase (alkB), Propane Monooxygenase (PrM), Cytochrome P450 (cP450), Methane Monooxygenase/Ammonia Monooxygenase (MMO/AMO) subunits A, B, and C, Alkane Sulfonate Monooxygenase (ssuD), Alkane Sulfonates Transport System Permease Protein (ssuC), Dibenzothiophene Monooxygenase (dszC), Dibenzothiophene-Sulfone Monooxygenase (dszA), and Dibenzothiophene-5,5-Dioxide Monooxygenase (dszB). These genes play pivotal roles in the degradation of aliphatic hydrocarbons and hydrocarbon desulfurization. Interestingly, unique gene expression patterns were observed for each amendment, with Actinomycetales and Bulkhoderiales orders expressing the majority of identified genes. These findings have revealed the amendment-specific microbial and genetic alterations and, the diversity and potential of the annotated genes induced by the Bacillus altitudinis-Cropped Biofertilizers (biosolid and BSG amendments) for effective remediation of hydrocarbon-contaminated soils.

Response of petroleum-contaminated soil to chemical oxidation combined with biostimulation

In this study, a microcosm experiment was conducted to investigate the effects of Na2S2O8 preoxidation combined with biostimulation on petroleum-contaminated soil remediation. The response of microbial community during this process was explored using BIOLOG ECO microplate carbon utilization method and 16 s rDNA high-throughput sequencing. The results showed that use of 10 mg/g Na2S2O8 removed 19.8 % of the petroleum hydrocarbons, reduced soil biotoxicity and did not affect soil microbial activity compared to other concentrations. Therefore, sodium persulfate of ca. 10 mg/g was used to oxidize petroleum in soil before the biostimulation experiment with organic and inorganic fertilizers. Our finding showed that the content of total petroleum hydrocarbons (TPHs) in soil was reduced by 43.3 % in inorganic fertilizer treatment after 60 days. The results of BIOLOG ECO microplate carbon utilization analysis and 16 S rDNA high-throughput sequencing further confirmed that biostimulation quickly restored the microbial activities in oxidant treated soil. The main marker bacteria in chemical oxidation combined with biostimulation remediation were Arthrobacter and Paenarthrobacter, and their relative abundances were both significantly negatively correlated with the content of petroleum hydrocarbons in soil.

Indigenous fungi with the ability to biodegrade hydrocarbons in diesel-contaminated soil are isolated and selected using a simple methodology

Soil contamination by hydrocarbons is a problem that causes severe damage to the environment and public health. Technologies such as bioremediation using native microbial species represent a promising and environmentally friendly alternative for decontamination. This study aimed to isolate indigenous fungi species from the State of Rio de Janeiro, Brazil and evaluate their diesel degrading capacity in soils contaminated with crude oil. Seven filamentous fungi were isolated after enrichment cultivation from soils collected from contaminated sites and subjected to growth analysis on diesel nutrient media. Two fungal species were pre-selected and identified by morphological genus analysis and molecular techniques as Trichoderma asperellum and Penicillium pedernalense. The microdilution test showed that T. asperellum presented better fungal growth in high diesel concentrations than P. pedernalense. In addition, T. asperellum was able to degrade 41 and 54% of the total petroleum hydrocarbon (TPH) content present in soil artificially contaminated with diesel (10 g/kg of soil) in 7 and 14 days of incubation, respectively. In higher diesel concentration (1000 g of diesel/kg of soil) the TPH degradation reached 26%, 45%, and 48%, in 9, 16, and 30 d, respectively. The results demonstrated that the selected species was suitable for diesel degradation. We can also conclude that the isolation and selection process proposed in this work was successful and represents a simple alternative for obtaining native species with hydrocarbon degradation capacity, for use in the bioremediation process in the recovery of contaminated areas in an ecologically acceptable way.

Bioremediation of Heavily Contaminated Sandstone from Bida Basin: A pre-emptive model for hydrocarbon exploration in the basin using Bacillus Sustilis and Cereus spp

Petroleum, often known as crude oil, is a complex organic mixture that naturally exists beneath the surface. There is often extreme pollution and other dangerous conditions associated with its exploration, production, refining, storage, and distribution activities. Thus, it is vital to carefully consider the best options after hydrocarbons are found in the Bida Basin, especially in regards to oil spills. In order to prevent this, this study created a preventive model by contaminating samples of sandstone from the Doko Member of the Bida Basin with spent engine oil, which is known to contain a higher percentage of nitrogen and sulfur compounds, aromatic and aliphatic hydrocarbons, and metals like manganese, calcium, zinc, and lead than fresh oils. Two (2) bacterial isolates with a high potential for engine oil biodegradability—Bacillus Subtilis and Cereus—were utilized to assess the effectiveness of total petroleum hydrocarbon (TPH) removal, which is a crucial aspect of crude oil detection. A weekly monitoring program was used to track various physicochemical characteristics of the wasted engine oil, including pH, bacterial biodegradation rate, total petroleum hydrocarbon, nitrate, phosphate, and total organic carbon content. After fourteen and twenty-eight days of contamination, respectively, the test results showed ~50% to &lt;70% biodegradation rate. So, when hydrocarbon development in the Bida Basin begins in earnest, NNPC will have access to first-hand technology for environmental cleanup at a very cheap cost, demonstrating the effectiveness of Bacillus Cereus and substilis as hydrocarbon biodegradation tools.

Negative Health and Environmental Effects of Oil Exploitation in Southern Ijaw, Bayelsa State, Nigeria

This research delves into the effects of oil extraction on the ecosystem in Southern Ijaw, Bayelsa State, Nigeria. It specifically examines the degree of degradation, identifies pollutants, and evaluates biodiversity. The water and soil samples taken from the impacted areas have significant pollution, according to the results. According to soil analysis, heavy metal and Total Petroleum Hydrocarbon (TPH) concentrations are high and above legal limits. Elevated TPH levels in water bodies present hazards to both human health and aquatic life. The loss of mangroves and the damage caused by oil spill fires to the vegetation worsen ecological degradation. Air pollution and contaminated water supplies are the main causes of the widespread negative effects on public health, which include respiratory conditions and waterborne infections. The report emphasises how urgently environmental degradation must be stopped, biodiversity must be preserved, and public health must be protected in oil-producing areas like Southern Ijaw.

Embryonic exposure to water accommodated fraction of crude oil inhibits reproductive capability in adult female marine medaka (Oryzias melastigma)

The water accommodated fraction (WAF) of spilled crude oil is a severe threat to the health of marine fish. This study was conducted to investigate the effects of short-term embryonic exposure to the WAF on the ovarian development and reproductive capability of F0 adult female marine medaka (Oryzias melastigma). Following embryonic exposure to the WAF with nominal total petroleum hydrocarbon concentrations of 0.5, 5, 50, and 500 μg/L for 7 days, the number of spawned eggs and gonadosomatic indices of F0 adult females were significantly reduced at 130 days postfertilization. In these F0 adult females, the proportion of mature oocytes was significantly lower, the level of 17β-estradiol was lower, and the level of testosterone was greater than those in control group. The mRNA levels of the follicle-stimulating hormone β subunit, luteinizing hormone β subunit, cytochrome P450 aromatase 19b, estrogen receptor α and β, and androgen receptor α and β genes were upregulated, while the mRNA level of the salmon-type gonadotropin-releasing hormone was downregulated in F0 adult females exposed to the WAF during the embryonic stage. Additionally, the methylation level of vitellogenin (vtg) in F0 adult females was significantly elevated, this might have, in turn, downregulated the mRNA level of vtg. The mortality rate of the unexposed F1 embryos was significantly increased and the hatching success was significantly reduced. These results collectively indicated the necessity of incorporating and evaluating the effects of short-term early-life exposure to crude oil in the assessment of risks to the reproductive health of marine fish.

Bioremediation of Soil Samples Contaminated with Crude Oil using Rice Husk-based Biocarbon (Oryza Sativa)

This research consisted of the bioremediation of four soil samples contaminated with oil using biochar made from rice husks. For this, fourth samples of soil Balao (B), Tachina (T), Refinería (R), and Winchele (W), from the province of Esmeraldas, Ecuador, previously contaminated with oil from a refinery in the country. The rice husk (Oryza sativa) was characterized to determine its ash, organic matter, and moisture content. The soil samples were characterized to know their cation exchange capacity, pH, temperature, humidity, organic carbon, ash, organic matter, density, porosity, and texture. The crude oil used as a soil contaminant agent was determined by API, temperature, Conradson carbon, density, ash, organic matter, and viscosity of the crude oil. Each sample was contaminated, and the bioremediation process was evaluated for 90 days. In the zero analysis, the content of total hydrocarbons (TPH) in sample B was 2,691.78 mg/Kg, 2,505.99 mg/Kg for T, 2,950.99 mg/Kg in R and W with 2,708.24 mg /Kg. Once the biochar was obtained, its pH, initial yield, density, ash content, organic matter, phosphorus, calcium, and magnesium were known. After bioremediation, concentrations of 475.61mg/Kg, 209.65mg/Kg, 136.66mg/Kg, and 578.05mg/Kg of TPHs were reached for B, T, R, and B, achieving compliance with the permissible limit established in local legislation for contaminated soils. The results obtained indicate that the process used can be an alternative to soil bioremediation processes.

Enhanced Natural Attenuation Technique, Edaphic and Microbiological Changes in Oil-Impacted Soil of Odhiaje Community, Rivers State

Oil spills in the Niger Delta could exert environmental pressures on the soil component. We investigated the impacts of oil spills and the effect of the Enhanced Natural Attenuation (ENA) remediation method on contaminated soil and resident microbial populations in the Odhiaje community in Rivers State, Nigeria. Soil samples for microbiological studies were collected weekly during a 17-week remediation period, while those for edaphic parameters were taken before and after remediation, all at 4 sampling points (SPs). Serial dilution of the oil-impacted soils for microbial density enumeration was carried out according to standard methods. Results revealed that mean concentrations of Total Petroleum Hydrocarbon Contents (THC) (Sig.value = 0.009), SO42- ions (Sig.value = 0.001), and sand compositions (Sig.value = 0.045) all differed markedly across the sampling points at p&lt;0.05. Mean levels of EC (Sig.tvalue = 0.039) and ΣN (Sig.tvalue = 0.058) &amp; K+ ions (Sig.tvalue = 0.004) differed significantly before and after the remediation exercise at the 95% confidence interval. Application of nutrients was rapidly accompanied by microbial population increases, leading to the consumption of oil contaminants in soils to levels comparable to control over the remediation period. Total Heterotrophic Bacteria counts correlated with pH (r = 0.501) and SO42- ions (r = 0.500) (p&lt;0.05), and K+ ions (r = -0.800) (p&lt;0.01); Total Heterotrophic Fungi correlated with pH (r = 0.520) (p&lt;0.05), and Mg2+ ions (r = 0.820) (p&lt;0.01); Hydrocarbon Utilizing Bacteria correlated with available P (r = 0.530) and silt composition (r = -0.504) (p&lt;0.05), and K+ (r = 0.626) and Mg2+ ions (r = 0.733) (p&lt;0.01); and Hydrocarbon Utilizing Fungi correlated with K+ (r = 0.500) &amp; Mg2+ ions (r = 0.506) (p&lt;0.05). Results indicate improvement in C/N ratios and effectiveness of the current cost-effective bioaugmentation technique in the restoration of arable soil productivity in the Odhiaje community.