Crude Oil Pollution Research Articles

Phytoremediation of Oil-Contaminated Soil by Tagetes erecta L. Combined with Biochar and Microbial Agent

Crude oil pollution of soil is an important issue that has serious effects on both the environment and human health. Phytoremediation is a promising approach to cleaning up oil-contaminated soil. In order to facilitate phytoremediation effects for oil-contaminated soil, this study set up a pot experiment to explore the co-application potentiality of Tagetes erecta L. with two other methods: microbial agent and biochar. Results showed that the greatest total petroleum hydrocarbon (TPH) biodegradation (76.60%) occurred in the soil treated with T. erecta, a microbial agent, and biochar; the highest biomass and root activity also occurred in this treatment.GC-MS analysis showed that petroleum hydrocarbon components in the range from C10 to C40 all reduced in different treatments, and intermediate-chain alkanes were preferred by our bioremediation methods. Compared with the treatments with biochar, the chlorophyll fluorescence parameter NPQ_Lss and plant antioxidant enzyme activities significantly decreased in the treatments applied with the microbial agent, while soil enzyme activities, especially oxidoreductase activities, significantly increased. Although the correlation between biochar and most plant growth and soil enzyme activity indicators was not significant in this study, the interaction effect analysis found a synergistic effect between microbial agents and biochar. Overall, this study suggests the co-addition of microbial agents and biochar as an excellent method to improve the phytoremediation effects of oil-contaminated soil and enhances our understanding of the inner mechanism.

Adsorption properties and competitive adsorption mechanism exhibited by carbon-nanotube-modified biochar for removal of crude oil and Ni(II) pollutants from water.

Carbon-nanotube-modified biochar (CNT3-CBC) with a nanostructured surface was prepared by using cattle manure as the raw material via the impregnation method. This modified biochar was then used to adsorb petroleum and Ni(II) from aqueous solutions. Various physicochemical characterization techniques were employed, including SEM, BET analysis, FTIR, and XPS. Kinetic and isothermal adsorption characteristics were analyzed. The influence of different biochar dosages, solution pH levels, and number of adsorption cycles on the efficiency of removal of crude oil and Ni(II) was meticulously evaluated. Results indicated that modified biochar had a higher surface area, a greater number of surface functional groups, and higher interaction forces compared to biochar. Adsorption kinetics and isotherms showed that modified biochar had a strong adsorption capacity. The experimental data conformed closely to the Elovich, Langmuir, and Freundlich adsorption models, underscoring the significant contributions of both physical and chemical adsorption mechanisms. Competitive adsorption of modified biochar in the co-sorption of petroleum and nickel solutions exists, and the modified biochar demonstrated high capacities for crude oil and Ni(II) in the competitive adsorption. The modified biochar prepared at a pyrolysis temperature of 800°C exhibited a superior adsorption performance, and the adsorption capacities of crude oil and Ni(II) were 303.03 mg·g-1 and 32.87 mg·g-¹ , respectively. Modified biochar has better regeneration potential after crude oil and Ni(II) adsorption, with the removal efficiency remaining above 50 % in the fourth cycle. As an efficient and environmentally friendly adsorbent, modified biochar shows great potential for removing crude oil and Ni(II) pollutants from water.

Isolation and Characterization of Effective Crude Oil Degrading Bacteria from Some Mussels Collected at Makaran Sea

Mussels are a group of beneficial marine organisms that have the ability to filter seawater so that seawater circulates inside the mussels and exits from the other side. Crude oil degrading bacteria exist in the tissue of mussels were enriched in ONR7a medium with crude oil as sole energy source. Some screening tests such as emulsification activity and bacterial adhesion to hydrocarbons were used for selection the best crude oil degrading bacteria. The quantity of heterotrophic bacteria was higher than degrading bacteria. Nineteen crude oil degrading bacteria were isolated from mussel’s samples collected from Makran shorelines. Most of the isolated bacteria were Gram-negative and bacilli. G5, O4, O10 and Q2 strains were selected as the best degrading strains based on screening analysis. The results of molecular identification showed that these four strains belonged to the following genera: Alcanivorax dieseloili Strain G5, Alcanivorax xenomutans strain O10, Halomonas denitrificans strain O4 and Pseudidiomarina aquimaris strain Q2. The results of this study showed that Makaran Sea have high diversity for degrading bacteria. If these bacteria were enriched and replicated in pilot phase the crude oil pollution can be managed in the real field at Makaran Sea.

The foraging behavior of gerbils reveals the ecological significance of crude oil pollution

Despite extensive ecotoxicological evidence on the adverse effects of oil pollution on rodents, little is known about how rodents make decisions in oil-polluted environments (i.e., outside of lab settings). We investigated the foraging behavior of Allenby gerbils, Gerbillus andersoni allenbyi (GA), that were presented with feeding trays in a semi-natural environment. The trays contained seeds mixed into one of three types of soils – clean soil, and two different soil samples collected from two well-documented terrestrial oil spill sites in Israel. The oil spill disasters occurred in 1975 and 2014 and the spill sites are located within a few hundred meters of each other, in the 'Avrona Nature Reserve in the Arava hyper-arid region in Israel.Gerbils of both sexes avoided foraging in 2014-polluted soil, but surprisingly, they foraged more in 1975-polluted soil. Our results indicate that for the GA, the 1975-polluted soil is an advantageous substrate to forage on, probably because its texture facilitates more efficient foraging, leading to greater energetic gain, and creating a trade-off between energetic gain and perceived foraging cost due to its pollution. We also proceeded to investigate some physiological consequences of chronic exposure to the 2014-polluted soil in the laboratory. Chronic oil exposure did not lead to mortality or weight loss, but female gerbils exhibited heightened cortisol. We conclude that terrestrial oil pollution may have significant sublethal impacts on animal behavior, even when there is no obvious short-term physiological cost to the exposure.

Crude Oil Biodegradation by a Biosurfactant-Producing Bacterial Consortium in High-Salinity Soil

Bioremediation is a promising strategy to remove crude oil contaminants. However, limited studies explored the potential of bacterial consortia on crude oil biodegradation in high salinity soil. In this study, four halotolerant strains (Pseudoxanthomonas sp. S1-2, Bacillus sp. S2-A, Dietzia sp. CN-3, and Acinetobacter sp. HC8-3S), with strong environmental tolerance (temperature, pH, and salinity), distinctive crude oil degradation, and beneficial biosurfactant production, were combined to construct a bacterial consortium. The inoculation of the consortium successfully degraded 97.1% of total petroleum hydrocarbons in 10 days, with notable removal of alkanes, cycloalkanes, branched alkanes, and aromatic hydrocarbons. Functional optimization showed that this consortium degraded crude oil effectively in a broad range of temperature (20–37 °C), pH (6–9), and salinity (0–100 g/L). In salt-enriched crude-oil-contaminated soil microcosms, the simultaneous treatment of bioaugmentation and biostimulation achieved the highest crude oil degradation rate of 568.6 mg/kg/d, compared to treatments involving abiotic factors, natural attenuation, biostimulation, and bioaugmentation after 60 days. Real-time PCR targeting the 16S rRNA and alkB genes showed the good adaptability and stability of this consortium. The degradation property of the constructed bacterial consortium and the engineered consortium strategy may have potential use in the bioremediation of crude oil pollution in high-salinity soil.

From Killer to Solution: Evaluating Bioremediation Strategies on Microbial Diversity in Crude Oil-Contaminated Soil over Three to Six Months in Port Harcourt, Nigeria

The study aimed to evaluate the efficacy of various bioremediation approaches on microbial diversity in crude oil-contaminated soil over three to six months in Port Harcourt, Nigeria. The objective was to assess the impact of different bioremediation strategies on microbial populations, particularly focusing on hydrocarbon-utilizing bacteria and fungi. Microbial populations were quantified using serial dilution and microbial count techniques. The vapor phase transfer mechanism was employed to estimate hydrocarbon-utilizing bacteria and fungi. Bacterial and fungal colonies were incubated for five days, followed by biochemical tests for isolate identification. Fungal pure cultures were observed under a microscope. The study observed a significant increase in microbial populations in soil free of crude oil pollution when bioremediators such as mushrooms and earthworms were introduced. Mushrooms exhibited a 50% increase in hydrocarbon-utilizing bacteria (HUB), while earthworms showed a 55% increase in HUB over the three to six-month period. The longer lifespan and nutrient absorption capabilities of earthworms facilitated faster growth. Furthermore, significant growth in the microbial population of hydrocarbon-utilizing bacteria and fungi was observed in crude oil-polluted soil after employing bioremediation, with the highest growth observed in soil treated with mushrooms at six months, followed by earthworms at six months. Conversely, the lowest microbial population was recorded in soil polluted with 10% crude oil and remediated with earthworms at three months. The results suggest that mushrooms and earthworms effectively increase microbial populations in crude oil-polluted soil. However, mushrooms demonstrated a higher microbial population increase compared to earthworms, especially in terms of promoting the growth of hydrocarbon-utilizing bacteria (HUB) and hydrocarbon-utilizing fungi (HUF). Based on the findings, it is recommended to prioritize using mushrooms as bioremediation agents in similar environmental restoration efforts due to their superior efficacy in increasing microbial populations, particularly HUB and HUF. This study underscores the potential of mushrooms and earthworms as effective bioremediation agents for restoring microbial diversity in crude oil-contaminated soil, offering insights for sustainable environmental restoration practices in oil-affected regions like Port Harcourt, Nigeria.

Exploring Alkali Hydroxide Influence on Calcium Titanate Formation for Application in Biodiesel Catalysts

Biodiesel has been recognized as the most widely utilized biofuel around the world due to its significant role in reducing the consumption of crude oil and lowering environmental pollution levels. By serving as a renewable alternative to fossil fuels, bioethanol helps decrease greenhouse gas emissions and contributes to a more sustainable energy future. Traditionally, alkali hydroxides like NaOH and KOH have been mainstays in biodiesel synthesis. However, their overuse can lead to unwanted byproducts and operational complexities. Since calcium titanate can occur at a strong base condition, it presents an alternative avenue worth exploring. In this study, we investigate the influence of alkali hydroxides, namely LiOH, NaOH, and KOH, on the formation of calcium titanate through hydrothermal methods, with varying heating times. We aim to understand how different hydroxides affect the synthesis process and the resultant properties of calcium titanate. We delve into the vibrational properties of Ca‒O‒Ti and Ti‒O bonds using Fourier transform infrared spectroscopy (FTIR), confirming the presence of calcium titanate (JCPDS No.42-0423) through X-ray diffractometry (XRD). This thorough characterization provides insight into the structural integrity and composition of the synthesized materials. Moreover, scanning electron microscopy (SEM) reveals the intriguing cube-like morphology of calcium titanate, offering visual evidence of its unique structure. The fatty acid methyl ester Iimpressively, our results show that calcium titanate synthesized in 7 M NaOH and KOH solutions, heated for 24 hours, emerges as a promising biodiesel catalyst. We observe fatty acid methyl ester provides the percentages of 63.67% and 90.02%, respectively, indicating the catalytic efficacy of these materials in biodiesel production. These findings not only contribute to the understanding of calcium titanate synthesis but also pave the way for a sustainable future in biodiesel production by introducing efficient and eco-friendly catalysts.

Double bioinspired of robust BaSO4/SnO2 membrane with anti-crude oil adhesion and remarkable emulsion separation

Pollution from oily waste water is a serious environmental problem worldwide, causing serious damage to the environment and human health. At the same time, emulsifiers also cause great difficulties in wastewater treatment. Although efforts have been made to develop many high performance emulsion separation membranes, it is difficult to have the ability to resist crude oil pollution in practical applications. The construction of superoleophobic micro/nano-scale lamellar structured membranes with the potential to efficiently separate oil/water emulsions was inspired by the oil-resistant properties of fish scales and the unique adhesion of mussels. Tin dioxide, polydopamine and hydrophilic barium sulphate have been modified on the surface of stainless steel mesh by in-situ hydrothermal and dip coating. The superhydrophilic stainless steel mesh was successfully prepared by using the adhesion of polydopamine. Using the excellent underwater hydration ability of tin dioxide and the hydroxyl group-rich hydrophilic barium sulfate, the modified membrane showed excellent resistance to crude oil pollution. The superhydrophilic membrane can continuously separate different types of oil-in-water emulsions with high separation efficiency (99.9 %) and excellent separation flux (900 L m−2 h−1), with no decrease in efficiency and flux after 10 emulsion separation cycles. In addition, the superhydrophilic membrane has excellent durability and stability, remaining super-oleophobic underwater to sand shock, sandpaper abrasion, high saline corrosion and UV ageing. The prepared stainless steel membrane not only provides a novel anti-fouling strategy, but its excellent stability also provides some new inspiration for the treatment of oil and water pollution in the future.

Impact of Crude Oil Pollution on some Geotechnical Characteristics of North Rumaila Soils in the Southern Iraqi Province of Basrah Governorate

Background: Pollution affects the soil and results in a change in its natural, chemical, or organic characteristics and properties, which directly or indirectly affect the geotechnical properties of the soil and make it unsuitable for engineering use. The aim of the study is to determine how adding various amounts of crude oil to the study area's soil affects the soil's geotechnical characteristics, including soil shear resistance, compaction coefficients, and California bearing capacity. Materials and Methods: The North Rumaila site was chosen for the study. At a depth of one meter, natural, pollution-free soil was extracted, and weight percentages of 2%, 4%, 6%, 8%, and 10% of crude oil were added. Grain size analysis, moisture content, direct shear, compaction, and Californian bearing tests were conducted. Results: The findings indicate that the soil at the North Rumaila site has a moisture content of 6.45% and is mostly silty sand with small amounts of clay and gravel. Crude oil was added to the soil, which caused the Californian to lose some of its bearing capacity, the optimal moisture content to raise, the angle of internal friction to decrease, and the bearing capacity of the soil to decrease. Conclusion: Pollution by crude oil effects negatively impacted the soil's geotechnical qualities.

Electrical resistivity imaging of crude oil contaminant in coastal soils – A laboratory sandbox study

Characterizing the subsurface distribution of crude oil after a spill in a coastal environment is challenging due to variations in the soil and fluid properties. In situ sampling is limited in capturing the lateral and vertical migration of the crude oil within the vadose and saturated zones. This study presents a laboratory sandbox framework used to assess the effectiveness of electrical resistivity imaging for investigating the spatiotemporal distribution of crude oil in coastal sandy soils. A sandbox with dimensions L = 240 cm, W = 60 cm, and H = 60 cm was constructed using a 10 mm plexiglass and filled to a 40 cm height with 2 mm medium to fine-grained sand. At each stage of the experiment, 20 kg of sand was mixed with 1 l of water to create moist sand, after which the mixture was flushed over 12 h to remove suspended fine particles. Both saturated and unsaturated conditions were simulated by setting the water table at 10 cm and draining a fully saturated system overnight. Two liters of crude oil were spilled and monitored for 30 h. A surface array of 98 electrodes, with a unit electrode spacing of 2 cm, was installed along two transects 12 cm apart. Resistivity measurements were collected using a dipole-dipole array before, during, and after the simulated crude oil spill. The time-lapse electrical resistivity results revealed an initial gravity-induced vertical migration under both saturated and unsaturated conditions; over time, lateral migration of crude oil became apparent. In the saturated zone, there was a noticeable reduction in the percentage difference in resistivity from 700 % to 400 % after 24 h, depicting a spatial and temporal redistribution of the crude oil attributed to variation in pore geometry. This highlights the sensitivity of electrical resistivity measurements to subtle but measurable anisotropy in the distribution of soil pores. Overall, electrical resistivity proved successful in imaging the non-ideal behavior of crude oil pollutants and the associated spatial changes in the pore-size distribution of subsurface sediments.

Spatial distribution of PAHs, nickel, and vanadium in sediments from a large coastal lagoon near a petroleum extraction area in the southern Gulf of Mexico

One of the world's crucial areas for crude oil exploration and extraction is the southern Gulf of Mexico, where Terminos Lagoon (TL) is located. Sediments from the TL region were used to assess the spatial patterns, origins, and ecotoxicological risks associated with 16 priority polycyclic aromatic hydrocarbons (PAHs; 3.1–248.9 ng⸳g−1 dry weight basis, dw) and trace metals (Ni = 11.0–104.0 mg⸳kg−1; V = 2.0–35.0 mg⸳kg−1 dw) linked to anthropogenic activities. Although origin indices based on PAHs and metals concentrations indicate no crude oil pollution in the region, sources of pyrogenic PAHs were identified. A chemometric approach demonstrated associations between organic matter and PAHs, and that metal accumulation depends mostly by the input of lithogenic materials. Ecotoxicological risk estimations showed a higher risk of possible adverse effects in sites near swamps and mangrove zones, highlighting the need of future monitoring. This study provides a reference for policymakers to conserve Mexico's largest coastal lagoon and other oil-impacted coastal areas worldwide.

Wood Sponge for Oil-Water Separation.

In addition to filtering some sediments, hydrophobic wood sponges can also absorb many organic solvents, particularly crude oil. The leakage of crude oil poses a serious threat to the marine ecosystem, and oil mixed with water also generates great danger for its use. From the perspective of low cost and high performance, wood sponges exhibit great potential for dealing with crude oil pollution. Wood sponge is a renewable material. With a highly oriented layered structure and a highly compressible three-dimensional porous frame, wood sponges are extremely hydrophobic, making them ideal for oil-water separation. Currently, the most common approach for creating wood sponge is to first destroy the wood cell wall to obtain a porous-oriented layered structure and then enhance the oil-water separation ability via superhydrophobic treatment. Wood sponge prepared using various experimental methods and different natural woods exhibits distinctive properties in regards to robustness, compressibility, fatigue resistance, and oil absorption ability. As an aerogel material, wood sponge offers multi-action (absorption, filtration) and reusable oil-water separation functions. This paper introduces the advantages of the use of wood sponge for oil-water separation. The physical and chemical properties of wood sponge and its mechanism of adsorbing crude oil are explained. The synthesis method and the properties are discussed. Finally, the use of wood sponge is summarized and prospected.

Modified Cotton Sorbent for Removing Crude Oil Pollution From Water: Sorption Kinetic Study

Modified Cotton Sorbent for Removing Crude Oil Pollution From Water: Sorption Kinetic Study

Treatment of crude oil-polluted water using CoFe2O4-doped mango (Mangifera indica) seed shell composite

This study investigates the potential of cobalt ferrite-doped mango seed shell (CoFe2O4-MSS) as an innovative and eco-friendly approach for the treatment of crude oil-polluted water. CoFe2O4-MSS was synthesized by impregnating carbonized mango seed shell with cobalt ferrite nanoparticles through thermal precipitation. The study systematically evaluated the adsorption capacity, kinetics, and isotherm behavior of the developed material using standard equations. Experimental results demonstrate the effectiveness of the cobalt ferrite-doped mango seed shell in adsorbing crude oil components, with high removal efficiency of 98.3% at 80 °C after 50 min. The crystallite sizes of raw mango seed shell and CoFe2O4-MSS are 31.8 nm and 21.3 nm, respectively. The calculated adsorption capacity stood at 55.50 mg/g, the Brunauer–Emmett–Teller surface area of CoFe2O4-MSS was 1007.4m2/g with a porosity distribution of 1.685 η\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\eta$$\\end{document} while the volume and pore diameter are 3.104m3/g and 7.212 nm, respectively. FTIR analysis revealed the presence of aliphatic, aromatic, and silicon compounds. The isotherm data matched well with Langmuir isotherm model while kinetic data fitted well with Bhattacharya–Venkobachar model. The unique properties of cobalt ferrite, a magnetic and iron-based material, combined with the abundant and biodegradable nature of mango seed shells, make this composite an attractive adsorbent for removing crude oil contaminants. This research contributes to the development of sustainable and cost-effective solutions for addressing environmental challenges posed by crude oil pollution. Also, this research has contributed immensely to the sustainable development goals of the united nation (UN-SDG) regarding environmental protection.

Molecular Characterization and Tolerance Potential of Culturable Crude Oil-Degrading Microbes in Santa-Barbara River, Bayelsa State, Nigeria

There has been chronic contamination of the surrounding aquatic and terrestrial environments in the Niger Delta region of Nigeria due to the enormous activities of crude oil exploration. This study aimed to characterize and assess the crude oil tolerance potential of indigenous microbes from crude oil spills in Santa Barbara River, Bayelsa State, Nigeria, that could serve as potential consortia for bioremediation of the crude oil spills. Total crude oil hydrocarbon-utilizing bacteria count (THUBC) and total crude oil hydrocarbon-utilizing fungi count (THUFC) in the samples were determined with a culture-dependent spread plate technique. Bacterial and fungal isolates were characterised using standard phenotypic and 16S/Internal Transcribed Spacer region rRNA gene sequencing techniques, respectively. The tolerance of autochthonous bacterial isolates to different concentrations of crude oil was subsequently determined. THUBC and THUFC in crude oil-polluted water samples ranged from 1.88 log10 CFU/ml to 2.74 log10 CFU/ml and from 0.00 log10 CFU/ml to 1.70 log10 CFU/ml, respectively. Representative strains of Proteus mirabilis, Bacillus subtilis, Pseudomonas aeruginosa, Micrococcus luteus and Aspergillus flavus isolates obtained from crude oil-polluted water samples were deposited in the GenBank (NCBI) under accession numbers OQ969924, OQ969951, OQ969987, OQ970009 and OQ975908. Proteus mirabilis, Pseudomonas aeruginosa and Aspergillus flavus demonstrated the most significant tolerance to crude oil pollutants (minimum crude oil inhibitory concentrations (MIC) = 80%) followed by Bacillus subtilis and Micrococcus luteus (MIC= 40%). The findings from this study are pointers to the potential role of the microbial isolates as bioremediation consortia to remediate the polluted Santa Barbara River.

Bioconcentration and lethal effects of gas-condensate and crude oil on nearshore copepod assemblages

The progressive establishment of gas platforms and increasing petroleum accidents pose a threat to zooplankton communities and thus to pelagic ecosystems. This study is the first to compare the impacts of gas-condensate and crude oil on copepod assemblages. We conducted microcosm experiments simulating slick scenarios at five different concentrations of gas-condensate and crude oil to determine and compare their lethal effects and the bioconcentration of low molecular weight polycyclic aromatic hydrocarbons (LMW-PAHs) in eastern Mediterranean coastal copepod assemblages. We found that gas-condensate had a two-times higher toxic effect than crude oil, significantly reducing copepod survival with increased exposure levels. The LMW-PAHs bioconcentration factor was 1–2 orders of magnitude higher in copepods exposed to gas-condensate than in those exposed to crude oil. The median lethal concentration (LC50) was significantly lower in calanoids vs. cyclopoid copepods, suggesting that calanoids are more susceptible to gas-condensate and crude oil pollution, with potential trophic implications.

Link between Oil Pollution and Adverse Pregnancy Outcomes in the Niger Delta Region of Nigeria

Oil exploration in the Niger Delta has led to severe environmental pollution. This study investigates the association between exposure to crude oil and adverse pregnancy outcomes. 
 Study Design: This was a comparative cross-sectional study of the differences in adverse pregnancy outcomes of people living in heavily oil polluted and non-polluted communities
 Place and Duration of Study: Kegbara Dere (K-Dere), a rural Community in Ogoniland, Gokana Local Government Area, Rivers State and Obohia community in Ndoki kingdom, Ukwa East LGA of Abia state between June 2022 and Jan 2023.
 Methodology: We recruited 900 study participants (450 each from the crude oil impacted and the non-oil polluted communities) using multi-stage random sampling. Questionnaires were used to collect data on socio-demographics and adverse pregnancy history by case definitions using the adapted WHO indirect sisterhood method of maternal mortality estimate. Data was analyzed using IBM Statistical Package for Social Sciences (SPSS) version 25. Differences in proportions were compared using Chi Square test. The association between living in an oil polluted community or exposure to crude oil pollutants and adverse pregnancy outcomes was determined using crude odds ratio. Confidence intervals were determined at 95% level and a p-value of less than 0.05 was considered significant.
 Results: Pregnant women in the polluted community experienced a significantly higher prevalence of adverse outcomes, including stillbirth, abortion, and birth defects. The risk of experiencing an adverse pregnancy outcome was 30 times higher in the polluted area.
 Conclusion: This study suggests a strong link between oil pollution and pregnancy complications. Further research with robust designs is needed to confirm causality. Environmental cleanup and protective measures for pregnant women are crucial in these areas.

Biostimulation potentials of spent milled maize and cowblood on a crude oil polluted soil

This study was carried out to investigate the biostimulation effect of the application of spent milled maize and cow blood to crude oil polluted soil. The treatment groups were; Control (0 L crude oil (CO) + 0 kg spent milled maize (SMM)), group 1 (1 L CO + 1 kg SMM + 1 L cow blood), group 2 (2 L CO + 2 kg SMM) and group 3 (5 L CO + 5 kg SMM). The experiment was laid out in a completely randomized design A total of four treatment combinations were applied and replicated 3 times giving a total of 48 plots.The physicochemical properties and bacterial load of the soil were determined before pollution, two weeks after pollution, four weeks and eight weeks after remediation. The results for physicochemical properties of soil indicates a decrease in total organic carbon and nitrogen while there was an increase in the levels of cation exchange capacity, phosphorus and electrical conductivity after crude oil pollution. The mean levels of total petroleum hydrocarbon and polycyclic aromatic hydrocarbon reduced after the pollution. The application of the spent milled maize and cow bloodwere observed to improve the physicochemical properties of soil. There was also an increased bacterial count for the treated groups compared to the control; the values ranged from 1.3 x 103cfu/g to 1.24 x 108cfu/g. The identified bacteria were Flavobacterium, Pseudomonas, Bacillus, Micrococcus, Proteus, Clostridium and Nocardia species.Generally, this study has revealed that spent milled maize and cow blood are effective in the restoration of crude oil polluted soil.

Effect of Crude Oil Polluted Soil on the Reproductive Growth of Plantain (Musa paradisiaca L.)

Soil polluted by crude oil is detrimental to the survival of plants and microbes. Plantain (Musa paradisiaca L.) is a major important food crop, showing tolerance to abiotic and biotic stress. This study investigated the impact of soil polluted with Bonny Light crude oil (BLCO) on the reproductive growth of two plantain cultivars. Crude oil was added to agricultural soil on which plantain suckers were planted. Reproductive growth was then periodically assessed. The number of suckers was significantly higher in French plantain plants grown on polluted soil in comparison with control. False Horn plantain plants on unpolluted soil produced more suckers in comparison to the plants on polluted soil. Also, the time between planting to flower bud appearance and flower bud appearance to bud opening reduced in plants on polluted soil in both cultivars in comparison with the control. Statistically, there was an insignificant decrease in the fruit size of False Horn plantain on polluted soil compared with the control while there was an appreciable increase with a significant effect in fruits size of French plantain on polluted soil compared with the control. Generally, French plantain tolerated the stress induced by crude oil pollution of soil in its reproductive growth more than False Horn. The reproductive growth of False Horn and French plantain cultivars show that there could be varied response to crude oil polluted soil.

Planning Implications of the Effect of Crude Oil Pollution on Germination and Growth Parameters of Mucuna Pruriens (Var Cochinchinesis) Fabacea in Aluu Town, Rivers State, Nigeria

The effect of varying concentrations of crude oil pollution on the germination and growth parameters of Mucuna pruriens (Var. cochinchinenesis) was investigated. The following treatments were used; 0ml, 100ml, 200ml, 400ml, 800ml 1600ml respectively. The germination of velvet bean was 100%, but growth was inhibited by a wide range of treatments (800ml and 1600ml). The lag phase of proceeding growth is also reduced at this treatment. Growth inhibition is attributed primarily to the characteristics of oil, which acts as a physical barrier to water and oxygen uptake. It was observed that the plants with the polluted treatments had reduced development and growth as against the non–polluted treatment (control) due to the toxic consequence of the crude oil on the geomorphological parameters (Number of leaves, leaf area, and plant height) tested for Velvet beans treated with lower treatment (100ml and 200ml) were observed to be more productive when compared to the control experiment. Consequently, as the crude oil exceeds the plant absorbing capacity at 800ml and 1600ml, respectively, the growth retards, chlorosis, presence of tough apical meristem, and defoliation from the base of the plant.