Level Of Oil Pollution Research Articles

Variations of Structural and Functional Traits of Azolla pinnata R. Br. in Response to Crude Oil Pollution in Arid Regions

In oil-producing countries, water pollution by crude petroleum oil frequently occurs and causes many environmental problems. This study aims to investigate the effect of crude petroleum oil on the growth and functional trails of the economically important freshwater plant Azolla pinnata R. Br. and to report on the plant’s resistance to this abiotic stress. Plants were raised in an open greenhouse experiment under different levels of crude oil pollution ranging from 0.5 to 2.0 g/L. Plant functional traits were monitored over a three-week period. Plant cover of A. pinnata was decreased with the increased levels of oil pollution. The total chlorophyll content decreased from 0.76 mg/g fresh weight under 2 g/L oil treatment after 21 days of growth. The chlorophyll a/b ratio exceeded the unity at crude oil treatments above 1 g/L, with values reaching 2.78 after seven days, while after 21 days, the ratio ranged from 1.14 to 1.31. The carotenoid content ranged from 0.17 mg/g in the control to 0.11 mg/g in the 2 g/L oil treatment. The carotenoid content varied over time in relation to DNA% damage, which increased from 3.63% in the control to 11.36% in the highest oil treatment level of 2 g/L. The crude oil stress caused severe damage in the frond tissues and chloroplast structure of A. pinnata, including a less compacted palisade, the malformation of the epidermis, the disintegration of parenchyma tissue, and the lysis and malformation of the chloroplasts. Since A. pinnata cannot withstand high concentrations of crude oil pollution, it is for use in the remediation of slightly polluted freshwaters up to 0.5 g/L.

Recording gear-type pump acoustic signals for assessing the hydraulic oil impurity level in a hydraulic excavator transmission

Mechanization and development of mining machines increase the importance of maintenance quality of working bodies and the machines themselves. This requires implementing improvements in technical maintenance processes. Improving technical maintenance implies the implementation of condition monitored maintenance that also allows real-time monitoring of the technical status. As hydraulic oil pollution is one of the major causes of breakdowns, it is recommended to implement oil pollution monitoring methods that will allow estimating the real-time oil pollution level. Today, sampling is the most widespread method of pollution level control. This method is time-consuming and that is why there are many attempts to devise new methods of monitoring the real-time oil pollution level. One of such methods includes recording of the acoustic-emission signal. In this work, we suggested that increase in transmission oil pollution level leads to increase in acoustic-emission signal in 20-300 kHz range. This increase in the acoustic level will indicate the pollution of oil with solid particles and alert the maintenance crew of the necessity of replacing the oil. This method allows real-time monitoring the hydraulic oil condition not associated with high labor, time, or economic costs.

Clonal integration in Phagmites australis mitigates effects of oil pollution on greenhouse gas emissions in a coastal wetland

Clonal integration, i.e., resource sharing within clones, enables clonal plants to maintain biomass production when ramets (asexual individuals) under stress are connected to those not under stress. Oil pollution can strongly reduce biomass production, and connected ramets within clones may experience different levels of oil pollution. Therefore, clonal integration may help plants maintain biomass production despite oil pollution. Because biomass production is often negatively correlated with greenhouse gas emissions, we hypothesized that oil pollution would increase greenhouse gas emissions and that clonal integration would reduce such an effect. We tested these hypotheses in a coastal wetland dominated by the rhizomatous grass Phragmites australis near a major site of oil production in the Yellow River Delta in China. We applied 0, 5, or 10 mm crude oil per year for two years in plots within stands of P. australis and tested effects of severing rhizomes connecting ramets inside and outside a plot (i.e. preventing clonal integration) on biomass production, soil chemistry and greenhouse gas emissions. When severed, ramets inside plots with no added oil produced about 220 g aboveground biomass m‐−2 over the second growing season, and plots absorbed about 500 g total CO2 equivalents m−2. Adding 10 mm oil per year reduced aboveground biomass by about 30%, and caused plots to emit about 800 g CO2 equivalents m−2. Leaving ramets connected to those outside plots eliminated the negative effects of oil pollution on biomass production, and caused plots given 10 mm oil per year to emit about 50% fewer total CO2 equivalents. We conclude that oil pollution can increase greenhouse gas emissions and clonal integration can reduce the effect of oil pollution on biomass production and greenhouse gas emissions. Our study provides the first experimental evidence that clonal integration in plants can reduce greenhouse gas emissions.

Effects of Oil Pollution on Water Movement in Soils with Different Textures

Exploring water movement characteristics in oil-polluted soils could facilitate the understanding of soil stress resistance. The aim of the present study was to evaluate the effects of oil pollution on water movement in soils with different textures and explore the underlying mechanisms. A heavy loam (Earth-cumuli-Orthic Anthrosols, EOA), a light loam (Hapli-Ustic Cambosols, HUC), and a sandy loam (Usti-Sandic Primosols, USP) were spiked with different levels of crude oil (0, 0.5, 1, 2, and 4%, w/w). Soil water movement parameters, including saturated hydraulic conductivity, unsaturated hydraulic conductivity, and specific water capacity were measured. Soil water availability under different levels of oil pollution was also analyzed. According to the results, saturated hydraulic conductivity of all three soils decreased with an increase in the level of oil pollution, as did the unsaturated hydraulic conductivity of HUC and USP. Under 4% oil pollution, the saturated hydraulic conductivity of the EOA, HUC, and USP decreased by 52.8%, 81.7%, and 39.6%, compared with their respective unpolluted soils, while the unsaturated hydraulic conductivity of HUC and USP decreased by 78.0% and 39.9% at 20% soil water content. In addition, the unsaturated hydraulic conductivity of EOA decreased with an increase in oil pollution level when the soil water content was >25%; however, a reverse trend was observed at soil water content <25%. The specific water capacity of all soils increased first and then decreased with an increase in water suction, while it decreased with an increase in the level of oil pollution. The suction ranges corresponding to the available water content in the three soils were reduced by oil pollution, and the corresponding water-holding capacities were weakened. Oil pollution had major negative impacts on water movement in the soils with different textures, causing a decline in water infiltration and supply capacities, which could hamper soil drought resistance. However, the effects of soil texture on water movement were greater than the effects of oil pollution under the experimental conditions.

Response of Maize (Zea mays) on Crude Oil Polluted Soil after One Month of Remediation with Spent Mushroom Substrate

The study was conducted to evaluate the influence of different levels of crude oil pollution remediated with spent mushroom substrate (SMS) on the growth of maize after one month of pollution. Composite soil samples randomly collected were polluted with Bonny light crude oil (v/w) at a concentration of 0%, 2%, 4% and 6% in a perforated plastic pots with 6 kg of top soil (0-20) cm. Ten percent of decomposed SMS was applied on each of the pots. A month after remediation, four seeds of Oba Super 11 maize variety were sown into each pot and later thinned to two after germination. The design was Complete Randomized Design consisting of six treatments and four replicates. After eight weeks of the study, results revealed a reduction in plant germination rate (60%) in polluted (SCM) against (87%) in non-polluted (SM) soil. Plant germination was highest (93.8%) on natural soil (SSM) amended with SMS. Amendment of the polluted soil with SMS improved the germination of the plant from 60% to 75%. There was a significant (P&lt;0.01) decrease in plant height on polluted against natural soils. Amendment of the polluted soil with SMS slightly increased the height of the plant though not significant within the first six weeks of the study, however, a significant (P&lt;0.01) increase was observed on the seventh and eighth weeks of the study. Pollution of the soil with crude oil revealed significant (P&lt;0.01) reduction on some soil physico-chemical properties (available phosphorus, exchangeable cations (Ca, Mg and K), while a significant (P&lt;0.01) increase was observed on total hydrocarbon content, total nitrogen, total organic carbon and total organic matter on the polluted over natural soil. Amendment of the polluted soil with SMS improved the nutrient status of the soil as there was significant (P&lt;0.01) increase in the concentration of Ca, Mg, K, P and a reduction in the content of THC, TOC of the soil. Remediation of crude oil polluted soil, with spent mushroom substrate a month after pollution, improved soil fertility.

Zooplankton of a Taiga River under Chronic Oil Pollution

The species diversity and the quantitative characteristics of zooplankton in the Vatinskii Egan River have been studied in its middle and lower reaches. The river suffers considerable oil pollution. The zooplankton community of the river has been shown to have a relatively stable species structure in river reaches with different level of oil pollution. Zooplankton in taiga rivers running over swampy territories cannot be used as a reliable characteristic of the level of oil and oil product pollution, as it has a high recovery potential because of the very small size of water bodies on the catchment area. For the bioindication of oil pollution with the use of zooplankton, the most informative are the proportions of species within each group and the quantitative Shannon and Pantle–Buck indices, which account for the level of representation of each species in the community.

Hydrocarbon pollution of the Azov Sea water ecosystems and its differentiation

The object of the study is the aquatic ecosystem of the Sea of Azov, which has an important ecological and fishery significance. In terms of hydrocarbon (HC) pollution, it exceeds other marine bodies due to the large volume of the water runoff, making up about 1/8 of the volume of the sea, and a significant catchment area, 15 times larger than the sea area. The advantages and disadvantages of methods for the determination of hydrocarbons (HCs) in aquatic ecosystems are considered. The total HC pollution of different origin was estimated by the luminescence and infrared spectroscopy methods with the original compositions of HC mixtures applied. The degree of transformation of oil pollution is established. The content of biogenic HCs in water and bottom sediments has been estimated. Differentiation is carried out between oil and biogenic HCs in the aquatic ecosystem by the content of phytoplankton. Based on the obtained results and the analysis of long-term observations, a conclusion is drawn that an adequate assessment of the level of oil pollution of water and bottom sediments of the Sea of Azov could be possible only taking into account its biogenic HC background. The use of the results obtained will allow one to predict the regularities of changes in the chemical composition of the components of oil pollution, and justify methodically some features of the organization of environmental monitoring of the water ecosystem studied.

Bioresource capacity of the black sea and its development by the national fishery in the XX and XXI centuries

In this paper, the history of the formation, dynamics of structure, and species composition of the main objects of the national fishery in the Black Sea from the moment of the fall of the Crimean Khanate in 1783 up to today are analyzed, as well as the structure of commercial biological resources of the sea formed throughout the geological history of development of the Ponto-Caspian Basin (more than 30 million years). The geography and catch composition, scales, and methods of fish harvesting in the twentieth and twenty-first centuries are examined. The stages of intensification and reduction of fish harvesting success and the causes of these fluctuations (natural dynamics of population abundance, press of predatory species, hydrotechnical construction, marine pollution, overfishing, poaching) are identified. The author shows that at the end of the twentieth century, the Russian fishing industry entered a depressed state, while the other Black Sea countries increased their average annual total catch. At the same time, starting at the beginning of the twenty-first century, due to the lessening of press of warty comb jelly (Mnemiopsis leidyi), a decrease in the level of oil and chemical pollution of coastal and shelf waters in the northern Black Sea, and a reduction in industrial production on the seacoast and watershed territories, the ecological situation in the Russian territorial waters improved significantly and many formerly commercial fish populations started to recover.

Microscopic soil fungi - bioindicators organisms contaminated soil

In the paper there are considered methodological issues for the evaluation of soil biota in terms of oil pollution. Experimental studies have shown that under the exposure of a various levels of oil pollution meeting certain gradations of the state and optimal alteration in microbocenosis in sod-podzolic soils, there is occurred a transformation of structure of the complex of micromycetes and the accumulation of toxic species, hardly typical for podzolic soils - primarily represantatives of the genus Aspergillus (A.niger and A. versicolor), Paecilomyces (P.variotii Bainer), Trichoderma (T.hamatum), the genus of phytopathogens Fusarium (F.oxysporum), dermatophytes of genus Sporothrix (S. schenckii) and dark-colored melanin containing fungi of Dematiaceae family. Besides that there are presented data on the study of microbiocenosis of the urban soil, the urban soil differed from the zone soil, but shaped in similar landscape and climatic conditions, and therefore having a tendency to a similar response from the side of microorganisms inhabiting the soil. Isolated complex of soil microscopic fungi is described by many authors as a complex, characteristic for soils of megalopolises. This allowed authors of this work to suggest that in urban soils the gain in the occurrence of pathogenic species micromycetes also increases against a background of chronic, continuously renewed inflow of petroleum hydrocarbons from various sources of pollution. Because changes in the species composition of micromycetes occurred in accordance with the increasing load of oil, so far as microscopic soil fungi can be recommended as a bioindicator organisms for oil. In the article there is also provided information about the distinctive features of modern DNA identification method of soil microscopic fungi and accepted in our country methodology of isolation of micromycetes with the use of a nutrient Czapek medium.

Spatial Distribution Characteristics of Oil Spills in the Bohai Sea Based on Satellite Remote Sensing and GIS

Bing, L.; Xing, Q.-G.; Liu, X., and Zou, N.-N., 2019. Spatial distribution characteristics of oil spills in the Bohai Sea based on satellite remote sensing and GIS. In: Jung, H.-S.; Lee, S.; Ryu, J.-H., and Cui, T. (eds.), Advances in Remote Sensing and Geoscience Information Systems of Coastal Environments. Journal of Coastal Research, Special Issue No. 90, pp. 164-170. Coconut Creek (Florida), ISSN 0749-0208.In recent years, on account of the vast and persistent damage of oil spill accidents, it becomes essential to carry out a further study on oil spill distribution characteristics on sea. Routine satellite remote sensing surveillance on oil spills with Synthetic Aperture Radar (SAR) proved to be ideal for analyzing distribution of oil pollution in macro scale. In this research work, considering the presence of “look-alikes” phenomena on SAR images as well as current operational application of “confidence level”, a confidence-oriented oil spill geodatabase is initially designed and built for quantification analysis. Then, in view of the requirement of marine grid management, a common framework based on remote sensing and Geographic Information System (GIS) is proposed to map and reveal the spatial distribution of oil pollution, in the process of which, oil pollution index (OPI) is put forward to evaluate oil pollution levels, then oil pollution distribution map can be compiled in terms of OPI, and the relationship between oil pollution and oil spill risk source can be further analyzed. Finally, a case study of the Bohai Sea and the north of the Yellow Sea with five-year's inter-annual satellite monitoring data was studied. The results showed that, during the period between 2009 and 2013, the high frequency grids of potential oil spills mainly distributed in the Bohai Bay and the south of the Liaodong Bay. 77.03 % of detected oil spills were within a certain distance along the sea lanes or near the offshore platforms, indicating a high risk of oil pollution of these areas. Generally, this research work also benefits for yield for the first time a rather comprehensive distribution characteristics of potential oil spills in macro scale in the Bohai Sea combined with remote sensing and GIS technique, which will be beneficial for oil spill response, preparedness and risk management.

EFFECT OF NITROGEN AND HUMIC FERTILIZERS ON THE BIOCHEMICAL STATE OF OIL‐CONTAMINATED CHERNOZEM

Aim. In this paper, we aim to assess the effect of nitrogen and humic fertilizers on the biochemical state of oil‐contaminated chernozem.Methods. In order to simulate the oil pollu‐ tion, chernozem was exposed to oil doses constituting 1, 5 and 10% of the soil mass for 30, 60 and 90 days. For simulating bioremediation of oil‐contaminated chernozem, the following fertilizers were used: potassium and sodium humates, urea and nitroammophos. Nitrogen fertilizers – urea and nitroammophos having a nitrogen content of 46% and 15%, respectively – were applied to the soil for the purposes of restoring the equilibrium between carbon and nitrogen. Humic fertilizers (potassium and sodium humates) were applied to the soil for stimulating the indigenous oil destructive microbiota. In order to assess the biological activity of the soil, we determined catalase activity, invertase activity, as well as CO2 emission intensity.Results. The effect of urea, nitroammophos, potassium and sodium humates on the enzymatic activity and CO2 emissions of ordinary chernozem, which had been exposed to various doses of oil (1, 5 and 10% of the soil mass) for 90 days, was studied in a model experiment. Following the introduction of nitroammophos into soil with low levels of oil pollution, catalase activity decreased, whereas respiration and invertase activity increased. Urea introduced into the soil contaminat‐ ed with a 10% dose of oil stimulated catalase activity. At oil concentrations of 1 and 5%, the introduction of potassium and sodium humates had a stimulating effect on enzymic activity and carbon dioxide evolution.Conclusions. It is advisable to use the intensity of CO2 emissions released from the soil, as well as the invertase activity for diagnosing the state of chernozem con‐ taminated with oil (5‐10%) following the introduction of nitrogen and humic ameliorants. At lower doses of oil, it is advisable to assess the state of the soil following the introduction of nitrogen fertilizers by catalase activity.

Growth tolerance and remediation potential of six plants in oil-polluted soil

The aim of this study was to screen plant species for remediation of oil-polluted soil in a semi-arid loess area. Pot experiments were conducted to test six indigenous plant species: ryegrass (Lolium perenne), tall fescue (Festuca ovina), wheatgrass (Agropyron cristatum), alfalfa (Medicago sativa), erect milkvetch (Astragalus adsurgens), and caragana (Caragana korshinskii). Loessial soil was spiked with crude oil at five pollution levels (0, 0.5, 1, 2, and 4%, w/w). We analyzed plant growth parameters at different stages, soil oxidoreductase activities, and oil degradation rate under different treatments. Soil pollution by oil negatively affected the germination rate, plant height, and biomass of all six species while inhibiting soil dehydrogenase and catalase activities. These inhibitory effects increased with increasing oil pollution level, with 2% and 1% being the critical levels at which plant growth and soil oxidoreductase activities were significantly inhibited, respectively. Both oxidoreductase activities in the rhizosphere soil were significantly higher than those in the bulk soil, which led to a considerable increase in the degradation rate of total petroleum hydrocarbons (TPHs) in the rhizosphere. The plants showed varying remediation effects in the oil-polluted soil. Erect milkvetch and caragana showed potential for remediation of soil below the 0.5% pollution level, alfalfa for soil below the 1% pollution level, and ryegrass, tall fescue, and wheatgrass for soil below the 4% pollution level. The oil pollution level was negatively correlated with plant height, biomass, oxidoreductase activities, and TPH degradation rate for the six plants (p < 0.01), whereas plant biomass was positively correlated with plant height and TPH degradation rate (p < 0.01). Dehydrogenase activity was significantly positively correlated with catalase activity (p < 0.01), while both of them were positively correlated with TPH degradation rate (p < 0.05 and p < 0.01, respectively). In conclusion, the six indigenous plants exhibited different tolerances to oil pollution, among which ryegrass, tall fescue, and wheatgrass had the greatest potential for remediation of oil-polluted soil in the loess area.

Oil pollution of the western Gulf of the Ob coast

The article reports the results of the summer 2018 expedition to Cape Kamenny(of the Ob bay, Yamalo-Nenets Autonomous Region) and the nearby non-functioning oil product supply facility (OPSF).The aim of the study was to monitor the current environmental situation and assess the level of oil pollution of environmental objects on these territories. The field and laboratory studies revealed the need to treat and remediate the oil-polluted soils, water bodies and wetlands.The field surveys of the territories showed the presence of visible oil polluted sites. The results of the laboratory tests revealed an excess of maximal permissible concentration (MPC) levels (1.3 – 6.2 MPC) for the water bodies located near the sources of oil pollution. The soil samples near the OPSF demonstrate a significant excess of oil products content (up to 1474 times). The soils sampled at Cape Kamenny are characterized by smaller content of oil products.Since the non-functioning OPSF is situated on a territory that has always been poluted by oil, it seems necessary to develop a land remediation plan to rehabilitate the site and to prevent a further pollution of the adjacent territories due to the migration of the pollutants.The oil pollution levels established for Cape Kamenny territory indicate a fairly high level of anthropogenic pressure in this area. Due to the low comparatively low soil stability in the area, it appears necessary to augment the measures for controlling the oil products leakage and spills at all the potentially hazardous objects.

Microbiocenoses of Oil-Polluted Soils

The state of soil microbiocenoses at different levels of oil pollution was assessed. The microbiological activity of two types of soils (sod-podzolic and typical black earth) under the conditions of stress caused by oil pollution was determined. The regularities in variation of the ratio and total number of the main groups of microorganisms in different soil types were reveled. The compositions of microorganism species in polluted soils were determined. The dynamics of changes in microbiocenoses after one-time oil spiking was traced. A number of microbiological parameters, which can serve as markers of oil pollution in soil, were proposed.

Analytical Aspects of the Determination of the Total Concentration and Differentiation of Anthropogenic and Biogenic Hydrocarbons in Aquatic Ecosystems

Problems of determining the total concentration of anthropogenic and biogenic hydrocarbons in aquatic ecosystems are discussed. Hydrocarbons accumulating in water samples and bottom sediments are different in composition. Polycyclic aromatic hydrocarbons, resistant to degradation, are concentrated in bottom sediments; their amount in the aquatic environment is insignificant. It is shown that the level of oil pollution can be adequately assessed only taking into account the biogenic (natural) hydrocarbon background of water and bottom sediments of the investigated objects. A unified pattern for the analysis of water and bottom sediments for assessing the level of oil contamination of aquatic ecosystems taking into account the transformation of oil components and the origin of hydrocarbons of different genesis is proposed. A possibility of the differentiation of petroleum and biogenic hydrocarbons in aquatic ecosystems by the concentration of chlorophyll in them is substantiated.

KONSENTRASI MINYAK SAWIT MENTAH (CPO) DI KAWASAN PESISIR DUMAI PROVINSI RIAU

Dumai waters was categorized as being prone to oil spills, because the dominant industrial activities in the area, is crude palm oil (CPO) industry. This study aimed to determine the level of oil and fat pollution in Dumai Coastal Area of Riau Province. The determination of CPO in water and sediment was carried out through the tests in the laboratory. CPO concentration in Dumai Coastal Waters was still in the category of being unpolluted and it was safe for the environment. Keywords : Dumai Coastal Waters, CPO, oil and fat

Analysis of water retention characteristics of oil-polluted earthy materials with different textures based on van Genuchten model

The water retention characteristics of polluted soil systems are affected not only by the properties of the soil (e.g., texture) but also by those of the pollutants. This study aimed to evaluate the effect of oil pollution on the water-holding capacity of earthy materials with different textures. Three earthy materials (Lou, Loessial, and Aeolian sandy earthy materials) with different textures were treated with crude oil at five pollution levels (0, 0.5, 1, 2, and 4%). The soil water retention curve (SWRC) obtained for each treated sample was analyzed using the van Genuchten model. Oil pollution resulted in lower soil water retention in each case, with a leftward shift of the corresponding SWRC, and led to a decrease in the saturated water content of the earthy material, characterized by a marked increase in incomplete saturation, and a decrease in the residual water content (i.e., irreducible saturation). Oil pollution also determined a marked increase in the slope of the SWRC. The response of the SWRC to oil pollution was significantly influenced by the texture of earthy material, and the saturated water content of all earthy materials was strongly affected by the level of oil pollution. The residual water content of the heavier-textured Lou earthy material was also strongly affected by the oil pollution level, but no clear influence was found for the lighter-textured Loessial or Aeolian sandy earthy materials. The SWRC slope of the Aeolian sandy earthy material was sensitive to oil pollution, unlike those of the Lou and Loessial earthy materials. Oil pollution reduced the water-holding capacity of different earthy materials to an extent depending on the soil texture. Under low-suction conditions, a significant effect of oil pollution on earthy materials of different texture was generally observed, while under high-suction conditions, the effect of oil pollution was greater for heavier-textured earthy materials.

Study of the plasma proteome of Atlantic cod (Gadus morhua): Changes due to crude oil exposure

Oil contamination is an environmental issue of great concern and the necessity for background studies and monitoring programs to continuously evaluate the levels of oil pollution is required. In this study, Atlantic cod (Gadus morhua) were exposed to dispersed crude oil for 1 and 4 weeks to simulate environmental contamination. Fractionated plasma samples were then analysed by tandem mass spectrometry. In total, 717 proteins were identified and 10 new protein biomarker candidates were found. The significant proteome changes were related to the immune response by alterations in the levels of specific immunoglobulins, alpha-2-macroglobulin and galectin-3-binding proteins. After 4 weeks of oil exposure, a lowered level of a NLRC3-like protein was also observed. The results from this study provide insight into the Atlantic cod plasma proteome and into the toxicological effects and potential response mechanisms of short and long-term exposure to crude oil.

“Effect of giant rat’s tail grass (&lt;i&gt;Sporobolus pyramidalis p.beauv&lt;/i&gt;) on Total Petroleum Hydrocarbon (TPH) and Heavy metals content of crude oil polluted soils”

Soil contamination by crude oil has been an issue within the oil producing areas of the Niger Delta Nigeria and so, many remediation methods; including phytoremediation, the use of plants, have been adopted for the remediation of the affected soils. Such plants are expected to be safe and effective in the clean-up of hydrocarbons and heavy metals from oil polluted sites. Giant rat’s tail grass ( Sporobolus pyramidalis p.beauv ) is among the plants being proposed. This study therefore investigated in eight-weeks, the effects of giant rat’s tail grass ( Sporobolus pyramidalis p.beauv ) on the total petroleum hydrocarbon (TPH) and heavy metals content of contaminated soils. Residual TPH and heavy metals (chromium, Cr and lead, Pb) were quantified as an index for assessing the post-phytoremediated crude oil contaminated soils. Crude oil pollution levels of 25ml/kg, 50ml/kg and 100ml/kg on soils were respectively done alongside the unpolluted control. Remediation treatments of the test soils and the control with the plant were done after two weeks of pollution using three young seedlings of giant rat’s tail grass. Results from eight weeks remediation period showed that TPH (mg/kg) reduced from 496.55 to 257.90, 578.09 to 241.37, 602.61 to 198.80 and 21.27 to 6.22 on the test soils and the control respectively; Cr (mg/kg) from 5.86 to 1.23, 7.96 to 1.38, 9.76 to 1.65 and 4.26 to 0.63 on the test soils and the control respectively; and Pb (mg/kg) from 4.25 to 1.21, 5.26 to 2.31, 5.12 to 3.93 and 1.96 to 0.43 on the test soils and the control respectively. Soil analysis results from the study indicated that giant rat’s tail grass ( Sporobolus pyramidalis p.beauv ) has the potential to ameliorate crude oil toxicity at different crude oil contamination levels because of its ability to significantly (p>0.05) decrease the TPH and heavy metals content of the soil. Keywords : Total Petroleum Hydrocarbon, Heavy Metals, Phytoremediation, giant rat’s tail, crude oil contamination

Effect of Crude Oil Polluted Soil and Substrate Quantity on Some Morphological Characters of Pleurotus ostreatus (Jacq.) P. Kumm and Pleurotus pulmonarius (Fries) Quel Fruit Bodies

The study was conducted to determine the influence of different levels of crude oil pollution on some morphological characteristics of P. ostreatus and P. pulmonariusfruit bodies. Crude oil treatment was done at 2%, 4% and 6% levels to 2,500 g/kg of garden soil. A.gayanus substrate was used in two quantity layers of 150 g/kg (4 cm) and 300 g/kg (8 cm) and placed on top of the polluted soil before spawn inoculation. The Cap Size (C.S cm), Stipe Length (S.L cm) and Weight (Wt. g/kg) of each mature mushroom fruit body were determined. Data collected were analysed using Analysis of Variance (ANOVA), while mean separation was done using Duncan Multiple Range Test (DMRT). Results showed that mean and standard error mean (mean± SEM) of C.S, S.L, and Wt of fruit bodies of both oyster mushrooms were not significantly different at p<0.05. Therefore, the various levels of crude oil pollution (2%, 4%, and 6%), as well as A.gayanus substrate layers/quantities of 4 cm/150 g/kg and 8 cm/300 g/kg did not affect some of the morphological characters of the Oyster mushroom species studied.